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Saskatchewan Potash Belt - Vanscoy, Cory, Patience Lake, Allan, Colonsay, Lanigan, Jansen, Wynyard, Esterhazy -K1, K2, -K3, -K4, Rocanville, Russell-St. Lazare, Belle Plaine, Bethune/Legacy, Tugaske, Southey, Milestone, Albany, Broadview
Saskatchewan, Canada
Main commodities: Potash


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The Saskatchewan Potash Belt is composed of eleven significant mines and at least six advanced projects that exploit or target the potash bearing members of the Middle Devonian Prairie Evaporite Formation in the nested intracontinental Williston and Elk Point basins of central to SE Saskatchewan. These deposits form a chain which includes a cluster in the north around Saskatoon and a tail that extends to the ESE to SE to, and over the Manitoba border, as well as a less well defined parallel chain to the SW. The northwestern extremity of the belt is represented by the Unity Shaft and drill intersection near the Alberta border. Some ~165 km to the ESE, the cluster around Saskatoon in the NW, occupies the next 200 km of the chain, and includes, from the SW to east-west to ESE, the Vanscoy,   Cory,   Patience Lake,   Allan,   Colonsay,   Lanigan   and   Jansen   operations and Wynyard Project.
  These are followed by a gap of ~200 km to Esterhazy-K1, -K3   and   -K2,   Rocanville   and the   Russell-St. Lazare   mine at Harrowby, across the border in Manitoba. This second group to the SE of the 'gap' define a 5 to 100 km long trend. The Rocanville main shaft is 4 km west of the Manitoba border. The Russell-St. Lazare resource in Manitoba is a continuation of both the potash bed being mined at Rocanville, and the Esterhazy-K4 resource that is, in turn, bounded to the west by the resource mined at Esterhazy K1 and K2. Esterhazy K4 is being held in reserve to replace production lost through exhaustion of the other Esterhazy deposits. Although no mines have been developed in the gap referred to above, mineable resources have been tested at Bredenbury which appears to be a NW extension of the K4 resource, and the   Triton/Leech Lake Project   to the NW of that near Yorkton.
  The parallel chain ~200 km to the SW is centred on the operating   Belle Plaine   and   Bethune/Legacy   solution mines west of Regina, and from the NW to ESE, the   Tugaske,   Southey,   Milestone,   Albany   and   Broadview   advanced solution mining projects, to the NW and ESE of Regina.

All of these deposits and projects are described individually below and may be accessed from the links above.   Images showing the   location   of each of the major mines are at the end of the main text description, before the references.

Go also to:   Potash members of the Prairie Evaporite Formation,   Mineralogy of the potash members  and  Geologic Anomalies.

Total production from the main mines in Saskatchewan for the year of 2018 was 22.84  Mt of KCl (Broughton, 2019).

NOTE: In Saskatchewan, potash grades are quoted as K2O% equivalent. K2O% = 0.6317 x KCl%.   Conversely, KCl% = 1.583 x K2O%; and 1.907 x K%.   K% = 0.83 x K2O%.

Saskatchewan Potash Belt


GEOLOGICAL SETTING

  The Middle Devonian potash rich evaporites of the Saskatchewan Potash Belt are part of the sequence deposited within the Elk Point Basin that unconformably overlies, above a major hiatus, the less extensive Lower Palaeozoic Williston Basin. The latter is a large, oval shaped, intracratonic sedimentary basin in eastern Montana, western North Dakota, South Dakota, southern Saskatchewan, and south-western Manitoba, covering an area of ~765 km north-south and 480 km east-west. The Williston Basin lies above the Palaeoproterozoic, 1.9 to 1.8 Ga Trans-Hudson Orogen that is interpreted to have influenced the location of the sagging that produced the Williston Basin. The Elk Point Basin, in turn, lies beneath the Cretaceous Western Interior Seaway that connected the Arctic Ocean and Gulf of Mexico and separated the Canadian Shield from the Rocky Mountains. In the centre of the basin, the Proterozoic and Archaean basement are buried by ~5000 m of sedimentary rocks of the Williston and Elk Point basins, and the Western Seaway.
  Deposition within this stack of basins commenced during the Cambrian, although subsidence and basin infill were most intense during the Ordovician, Silurian and Devonian. This period saw thick accumulations of limestone and dolostone, with lesser sandstones, siltstones, shales and evaporites. Subsidence persisted on a lesser scale into the Lower Carboniferous, and had largely ceased by the Upper Carboniferous (Pennsylvanian), although Carboniferous rocks are largely absent from the Jansen area. A hiatus in the sedimentary record ensued that lasted until the Mid Triassic. Renewed, but less significant subsidence and sedimentation took place during the Triassic and Jurassic, followed by another hiatus until the subsidence that led to the Western Interior Seaway in the Lower Cretaceous. Toward the end of the Cretaceous, tectonic activity related to the Laramide Orogeny rejuvenated basement structures to induce folding within the sedimentary rocks of the Williston and overlying basins.

The stratigraphic succession within the nested Williston, Elk Point Basin and Western Seaway may be summarised as follows, from the base:

ARCHAEAN and PALAEOPROTEROZOIC BASEMENT

The Glennie Domain - which belongs to the Trans-Hudson Orogen, is characterised by Palaeoproterozoic arc volcanogenic assemblages and granitoid rocks that occur as thrust sheets over the intervening Archaean Saskatchewan (or Sask) Craton, prior to the final collision between the bounding Archaean Rae-Hearne and Superior provinces.
  Angular unconformity

CAMBRIAN to LOWER ORDOVICIAN

  Deadwood Formation, which is 0 to 800 m thick and was deposited between 500 and 480 Ma in the Lower Cambrian to Lower Ordovician. It is primarily composed of siliciclastics, which include quartz-rich sandstones, interbedded with siltstone and shale/claystone, whilst lesser carbonate beds are found within the middle and upper portions of the unit (LeFever et al., 1987; Sarnoski, 2015).

MID LOWER to MIDDLE ORDOVICIAN

  Hiatus in the sedimentary record.

MIDDLE ORDOVICIAN to EARLY DEVONIAN

  Winnipeg Formation - a complex sequence of interbedded sands and shales, ranging from 90% shale to >90% sands, deposited in a deltaic regime that progressed to shallow marine, to be covered by marine shales and dolomitic limestone. It ranges from 0 to 69 m in thickness and was deposited in the late Middle Ordovician.
Big Horn Group - of upper Ordovician age, subdivided into the:
  Red River Formation, which is of early Upper Ordovician age, and comprises cyclic successions of thick limestone and dolostone that are >200 m thick in the centre of the basin, thinning to zero to the east and south. The lower members of the formation are mostly sub-tidal to deep intertidal marine limestone. The upper half of the formation is divided into four depositional cycles, each comprising three parts, progressing from subtidal burrowed lime mudstone, to a middle, restricted intertidal to peri-saline laminated dolostone, to an upper anhydrite, deposited in a restricted peritidal to penesaline, and rarely a sabkha environment. This is conformably overlain by the,
  Stoney Mountain Formation, which was deposited between 449 and 443.7 Ma, and is 30 to 45 m thick, with pronounced lateral facies variations. To the south and centre it comprises interbedded, red to grey calcareous shales and highly fossiliferous limestones, overlain by thin, red to yellowish grey, argillaceous, fossiliferous dolostones. Further north, the shale content progressively decreases to a relatively uniform lithology of pale yellowish brown, faintly mottled, very finely crystalline, dense, sparsely fossiliferous dolostone, with thin nodular bedding. In the basin centre a thin 2.5 to 3 m evaporite, the Stonewall Anhydrite, occurs at the top of the the formation, followed by the lower sections of the conformably overlying Stonewall Formation.
  Stonewall Formation - which was deposited between 449 and 436 in the Late Silurian and Early Devonian, and extends throughout the basin, with a thickness that ranges from 15 to 34 m. It largely comprises pale yellowish grey, faintly mottled, finely crystalline, medium-bedded dolostone, generally sparsely fossiliferous.
  Interlake Group, which is 50 to 110 m thick, and conformably to disconformably overlies the Stonewall Formation and Big Horn Group, and extends throughout the basin, deposited between 443.7 and 418.7 Ma. It is primarily composed of pale yellowish grey to yellowish brown, very finely crystalline to sublithographic dolostones, with coarse fossil fragmental, oolitic, stromatolitic and biohermal interbeds. This relatively monotonous dolostone sequence is interrupted by a series of argillaceous and/or silty to sandy beds that can be correlated across the basin. It is overlain, across a gentle angular unconformity and hiatus, by the Devonian Ashern Formation.

EARLY to LATE MIDDLE DEVONIAN

Elk Point Group, which is of Middle Devonian age, deposited between 397.5 and 385.3 Ma in a marine embayment of the Elk Point Basin, that stretched from an open ocean in the present-day Northwest Territories of Canada, to North Dakota in the United States. This broader, elongate depository encompassed and extended beyond the area of both the Williston and contiguous Alberta Basin to its NNW, and represented a rejuvenation of subsidence after the preceding hiatus. Over its life, the Elk Point Basin was filled with a sequence primarily composed of carbonate lithologies (dolostone and limestone) and evaporitic rocks (halite, anhydrite and potash), with lesser dolomitic mudstone and shale. Although the basin was initially connected to the open ocean in the NW, emerging restrictions began to limit this connection, leading to an increase in salinity, which induced the deposition of the Prairie Evaporite Formation which hosts the potash bearing members.
  The Elk Point Basin is divided into three, from NW to SE, namely the Northern and Central Alberta, and the Saskatchewan sub-basins (see image above). These are bounded by a series of ENE-WSW aligned basement highs, specifically the Tathlina Uplift to the NW of the Northern Alberta Sub-basins, on which the Presqu’ile Barrier Reef complex was formed during the Devonian; the Peace River-Athabasca Arch between the Northern and Central Athabasca sub-basins; the Meadow Lake Escarpment separating the latter from the Saskatchewan Basin, and finally the Sioux Arch to the SE. The Elk Point Group was deposited in these three sub-basins, being thickest and best developed over a longer period in the Central Athabasca Sub-basin, during which there were several marine transgressions and regressive erosion events. Lower Middle Devonian sandstones, red beds and salt deposits of the up to 230 m thick Lotsberg Formation accumulated in the Central Alberta, and to a lesser degree the Northern Alberta sub-basins in a tectonically stable, continental environment (Meijer Drees, 2008). The first marine ingress led to the deposition of marine carbonates of the 12 to 23 m thick Ernestina Lake Formation, with red beds, evaporites, and peritidal sediments on the basin margin. This sedimentation constricted the connection with the open ocean in the NW, restricting circulation, and resulting in excessive evaporation and salt deposition of the 50 to 80 m thick Cold Lake Formation (Meijer Drees, 2008). The second marine incursion resulted in red beds and peritidal evaporites filling the Northern and Central Alberta sub-basins. A subsequent fall in sea level, regression and minor erosion was followed by a third marine transgression during the early Middle Devonian, resulting in shaly, nearshore, and peritidal carbonates onlapping the unconformity and southeastward gradation into peritidal and evaporitic carbonates of the up to 75 m thick Chinchaga Formation. This was accompanied by nearshore clastics or red beds of the 45 m thick Contact Rapids Formation of the Central Athabasca Sub-basin, and deposition of the Ashern Formation (see below) the basal unit of the group in the Saskatchewan Basin. The upper, regressive part of this assemblage includes a suite of shallow-marine carbonates known as the Winnipegosis Formation in the Central Alberta and Saskatchewan sub-basins. This formation immediately underlies the Prairie Evaporite Formation in the latter sub-basin (Meijer Drees, 2008).
  A fourth marine transgression in the late Middle Devonian was accompanied by vertical growth of the Presqu'ile Barrier Reef complex at the entrance of the Elk Point Basin to the NW, restricting the ingress of fresh sea water into the basin. Evaporation progressively increased as the marine brine flowed south, and eventually into the Saskatchewan sub-basin ~800 km to the SE, concomitant with it's increasing salinity and density. Deposition of evaporites from this inflow formed the Prairie Evaporite Formation.
  The permeability of the Presqu'ile barrier reef is interpreted to have allowed the inflow of seawater into the restricted sub-basins, although the water loss through evaporation is estimated to have been 200 to 800 times greater (Maiklem 1971). However, seepage alone is calculated to have been insufficient to produce the volumes of evaporites found in the basin in the projected time span for salt deposition, and restricted but continuous inflow of seawater through channels traversing the barrier reef is postulated (Nunn and Harris, 2007) during each marine incursion. Evaporites were deposited throughout the Elk Point Basin, laterally and vertically zoned from: carbonate rocks → gypsum (subsequently converted to anhydrite) → halite → halite + potassium chloride salts + potassium-magnesium chloride salts. Finally, the continued evaporation and supply of more saline marine water produced a thick alternating sequence of salt and four potash-bearing salt sequences, mainly restricted to the most distant Saskatchewan sub-basin (Brongersma-Sanders and Groen, 1970).
  Within the large-scale flooding episode responsible for the Prairie Evaporite Formation, there were several major cycles of alternating flooding and desiccation that correspond to the development of four major potash bearing salt members of the formation, the Patience Lake, Belle Plaine, White Bear and Esterhazy Members (Klingspor, 1966). In more detail, within each of these, there were also numerous cycles of sea water flooding and desiccation. Within the Patience Lake Member, at least 16 halite → sylvite plus halite → clay deposition cycles have been differentiated, while 7 additional incomplete cycles of halite → clay deposition may be present (Boys 1990). Potash deposition in those latter seven cycles was either not reached, or the potash was removed subsequent to deposition. The Belle Plaine and Esterhazy Members could represent a minimum of 4 to possibly >20 cycles of flooding, evaporation, and desiccation. The White Bear Member may have undergone fewer of these flooding, evaporation, and desiccation cycles as its thickness and grade are less than the other members.

Within the Saskatchewan Sub-basin, the Elk Point Group has been subdivided into the:
  Ashern Formation, a thin, up to 55 m thick Lower Devonian unit of brick-red to reddish-brown to greyish-orange shaly dolostone which may be sugary to crystalline and contrasts with the underlying pale Silurian dolostones. It sometimes contains anhydrite, and in the deeper parts of the basin grades to greenish grey with calcite rather than dolomite. It unconformably overlies the Silurian sequence, as described above, marking the base of the Devonian transgression into the Elk Point Basin, whilst it is para-conformably overlain by the,
  Winnipegosis Formation, which was deposited between 387.7 and 382.7 Ma in the Giventian of the Middle Devonian. The formation commences with a lower platformal carbonate, which is commonly a mottled dolostone, and extends throughout the Elk Point Basin with a fairly constant thickness of 13 m. This facies was deposited in a shallow-water, marine environment, and includes oncolitic packstone, with less common interlaminated argillaceous and carbonaceous mudstones, dolostone laminites, and intraformational conglomerates at its top. Bituminous carbonates are common, as are fossiliferous, algae-rich lime mudstone to wackestone (Kent, 1984). The platformal beds are overlain by an argillaceous interval separating them from thicker bank facies. The latter are characterised by pinnacle reefs, which form positive basement mounds that extend upwards, from a few metres, to as much as 110 m, into the overlaying Prairie Evaporite Formation. They are flat topped, and generally circular, with a diameter as large as 8 km across (Baar, 1972, 1973; Boys, 1990). Fossils are common in the carbonate banks, which, in outcrop, are structureless masses of fossiliferous, yellowish grey dolostone with fair to excellent porosity. The bank facies display both lateral and vertical variations in lithology and faunal content. The upper ~6 m of the banks/mounds are composed of dolomitised algal boundstones, packstones and grainstones, referred to as the 'algal cap unit', which extends laterally into adjacent anhydrite of the off-bank or bank-flank positions. Between the banks/mounds, the intermound facies are composed of up to 20 m of inter­laminated carbonate mudstone, enterolithic anhydrite, bituminous carbonate and anhydrite laminates of the Ratner Laminate Member that are 0.6 to 16 m thick (Wilson, 1985; Boys, 1990; Fu et al., 2006). These were most likely deposited in a quiet-water marine environment after most of the Winnipegosis banks had formed. Locally, the upper part of the formation is anhydrite, which may pass into the anhydrites of the basal Prairie Evaporite Formation.
  Prairie Evaporite Formation, which conformably overlies intermound facies carbonates or anhydrite at the top of the Winnipegosis Formation, is host to the potash resources of the Elk Point Basin. It was deposited between 387.7 and 382.7 Ma in the Givetian, over an area from north-central Alberta, SE through Swskatchewan into western Manitoba, and then south into North Dakota and Montana in the US. It reaches a maximum thickness of 218 m in a thicker band that extends from west of Saskatoon, east to Melville and then south into North Dakota.
  Along the southwestern margin of the Elk Point Basin, the 'salt beds' of the Prairie Evaporite grade into near-shore siliciclastic/clastic mixed facies lapping onto the Western Alberta Ridge and the southeastern Peace River Arch. In the NW, the principal lithology changes from evaporites → anhydrite of the Muskeg Formation and then → carbonates, including the reefal beds of the Presqu'ile Barrier. These carbonates of the Presqu'ile Barrier interfinger into the Northern Albert Sub-basin with the anhydrite Muskeg Formation, which comprises an ~160 m basal interbedded anhydrite and dolostone, an ~40m thick middle dolostone unit, and an ~14.5 m thick upper unit of interbedded limestone and dolostone (Meijer Drees, 1986). The Muskeg Formation grades southeastward into the Prairie Evaporite, which extends from the northern Alberta sub-basin, through the central Alberta, and then into the Saskatchewan sub-basin, representing an interval of some 880 km from the Presqu’ile barrier reef complex. The Presqu'ile Barrier developed across the mouth of the embayment, blocking it from the open ocean and restricting the inflow of sea water. Along both it's eastern margin, and in southwestern Saskatchewan, the Prairie Evaporite has undergone extensive dissolution of salts, which resulted in thickness irregularities, to the local absence of salts, particularly in south-central Saskatchewan to the south and SW of Saskatoon (Grobe, 2000).
  In general the Prairie Evaporite is composed of halite, sylvite and lesser carnallite (KCl•MgCl2•6H2O) of various colours and degrees of crystallinity, although predominantly red and moderately coarsely crystalline. Blue halite is locally present. Seams of red or grey dolomitic mudstone and some anhydrite beds are present.
  The Prairie Evaporite has been broadly divided into lower and upper sections, separated by a unit composed of anhydrite and laminated dolomite, variously known as the Middle Anhydrite (Holter, 1969), the Shell Lake Member, or the Shell Lake Marker Bed (Reinson and Wardlaw, 1972; Marsh et al., 2001; Zhang et al., 2001). This dividing unit is a good seismic reflector, and is composed of repeating upward successions of anhydrite, interbedded anhydrite and dolomite, and halite. It is split into the Upper and Lower Shell Lake Anhydrite by the Quill Lake Marker Beds that are composed of interbedded, laminated pellet packstones, algal stromatolitic mudstones, algal fragmented pisolitic and stromatlitic grainstones and packstones and wackestones, all of which are strongly dolomitised. The Shell Lake Member has been regarded as being continuous with the underlying Winnipegosis Formation reef mounds, although subsequent work demonstrates it terminates against/laps onto fully developed reef mounds. It is best developed in a broad linear trend along the NE margin of the basin, below the string of significant potash deposits between Saskatoon in the NW and Picton in the SE, and varies from 1 to 5 m in thickness, with thicker sections, where it may locally reach 40 m. The Prairie Evaporite section below the Shell Lake Member has been referred to as the Whitkow Member, and is composed of a Lower Anhydrite, and an Upper Salt Unit. The Lower Anhydrite overlies the intermound facies of the Winnipegosis Formation and is ~10 m thick. It is composed of nodular mosaic and massive anhydrite; nodular-bedded, dolomitic anhydrite; distorted, nodular-mosaic anhydrite; and streaky, laminated anhydrite. These anhydritic beds contain remnant dolostone clasts and dolomitic fossil fragments or pisoliths (Klingspor, 1966; Bebout and Maiklem, 1973; Corrigan, 1975). The Upper Salt Unit of the Whitkow Member is ~60 m thick, and is composed of recrystallised, semi-translucent halite with minor, generally <1 cm thick intercalated, light grey, anhydritic laminae (Reinson and Wardlaw, 1972; Meijer Drees, 1986). The lower anhydrite, and the overlying halite sections of the Whitkow Member were deposited between, and lap onto the bank facies of the Winnipegosis Formation, and neither are found between the latter and the Shell Lake Member, which also laps onto, but also elsewhere unconformably overlies the eroded upper section of the reef banks.
&nbs; On a smaller scale, alternating halite and anhydrite laminae (or couplets) that occur in the lower part of the Prairie Evaporite are believed to represent a primary deposition of halite and gypsum related to a cyclic influx of seawater or brine (Wardlaw and Schwerdtner, 1966).
  Above the Shell Lake Member a thickness of predominantly halite similar to the upper salt unit of the Whitkow Member is developed. This unit appears to vary from <10 to as much as 90 m (e.g., Yang, Love and Smith, 2021) in thickness. It is capped by the appearance of potash interbeds, which include the Esterhazy, White Bear or Belle Plaine members in different parts of the basin. Laminae and thin beds of sylvite and/or carnallite appear as these potash members are approached from below.
  The upper 100 m of the Prairie Evaporite incorporates a number of halite and potash bearing interbeds, that are variably developed throughout large areas of the Saskatchewan Sub-basin of the Elk Point Basin, with individual members being absent or present, or economic, or uneconomic, at different mines. The potash-rich intervals are referred to as 'members', and the intercalated halite-rich intervals are known as 'interbeds'. The potash-bearing members are stratabound and consist mainly of sylvite or carnallite intermixed with halite, to form sylvinite and carnallitite beds. The halite interbeds may contain thin bands of potash-bearing salt as well as disseminated potash minerals. The halite interbeds above a mined potash member, known as a 'salt-back', are important in that they serve as both a competent roof (back) and an impermeable barrier to protect the potash-bearing salt and mining operations from groundwater inflow and flooding from overlying aquifers. A minimum salt-back thickness of 9 m is a commonly accepted requirement for conventional underground mining in Saskatchewan (Yang et al,, 2009).
  Each of the potash-bearing members is composed of a series of bedded evaporite cycles (Holter, 1969), each of which commences at the base with a mixture of halite and lesser sylvite (or carnallite dominated by halite), that grades upward with progressively reducing halite content, into dominantly sylvite or carnallite with little or no halite. The amount of insoluble minerals also increases upward in each cycle. The cycles are eventually capped by a thicker bed of insoluble minerals or a clay seam, which become more abundant in the younger members and particularly in the Patience Lake Member (Boys, 1990; Yang et al., 2009). Insoluble materials within the halite and potash salts are primarily clay, quartz, anhydrite and dolomite.
  The typical potash/sylvinite bearing members within the Prairie Evaporite Formation are composed of a mass of interlocking sylvite crystals that range from pink to translucent and may be rimmed by greenish-grey clay or bright red iron-rich insoluble material, with minor halite, randomly disseminated throughout. Locally, large 2 to 3 cm translucent to cloudy cubic halite crystals may be present within the sylvite groundmass. Overall, the sylvinite ranges from a dusky brownish-red coloured, lower grade (23% to 27% K2O with increased insoluble material) to a bright, almost translucent pinkish orange coloured high grade (>30% K2O). Carnallite is also locally present. The intervening barren salt bands between the potash beds comprises brownish red, vitreous to translucent halite with minor sylvite and carnallite and increased insoluble material.
  The potash bearing members and interbeds of the Prairie Evaporite Formation are described in detail separately below. The four main potash members, from the lowest to highest, each of which is separated by halite interbeds, are as follows:
  • Esterhazy Member - the lowest in the sequence, overlies >10 m of halite and varies from 1 to 15 m in thickness, with a mean of 9 m, although locally it may be 30 to 40 m thick, as in the Esterhazy mines. The mean potash grade is 15.3% K2O. It is separated from the Belle Plaine member by the 11.1o to 43 m thick Interbed 1 which encloses the thinner White Bear Member.
  • White Bear Member - a distinctive thin marker horizon of interbedded clay, halite and sylvinite horizons that are not conventionally mineable due to insufficient thickness and/or grade. It ranges from 1 to 10 m thick with a mean of 4 m. The mean potash grade is 10.66% K2O.
  • Belle Plaine Member - which, generally varies from 3 to 12 m in thickness with a local maximum of 23 m, and a mean of 7 m. The mean potash grade is 15.98% K2O. It is separated from the overlying Patience Lake Member by the 5.5 to 6 m thick Interbed 1, predominantly composed of halite.
  • Patience Lake Member, divided into the Lower (or B Zone) and Upper (or A Zone) Patience Lake Members. Overall it varies from 3 to 12 m in thickness with a local maximum of 23 m and a mean of 7 m. The mean potash grade is 17.6% K2O
  The Esterhazy and White Bear members are largely restricted to the southeastern cluster of mines, whilst the Belle Plaine Member is developed throughout, although mostly not economic, except for solution mining, as at Belle Plaine and Bethune. The Patience Lake Member is restricted to the northwestern main cluster around Saskatoon, with only the upper zone being mineable in the NW, whilst both are economic in the SE of the cluster, as at Jansen and Lanigan.
  However, most of the advanced solution mining projects plan to mine multiple potash members. Milestone, Albany, Tugaske, Southey and Wynyard are all scheduled to exploit the Esterhazy, Belle Plaine and Patience Lake members, whilst Broadview will leach the Esterhazy and Patience Lake members only, due to the local absence of the Belle Plaine Member.
  The development and preservation of the four main potash members of the Prairie Evaporite Formation migrated from SE to NW with time, from the Esterhazy → White Bear → Belle Plaine → Patience Lake members, each dipping to the NW below its predecessor in the list. The Patience Lake Member, is the most extensive, covering an area of ~800 x 250 km.
NOTE: The geology of the individual potash members are described in more detail later.

LATE MIDDLE to UPPER DEVONIAN

Manitoba Group, which was deposited between 397.5 and 359.2 Ma, and extends from southwestern Manitoba in the east, westward over the area of the Elk Point Basin of southern Saskatchewan, and into adjoining areas of North Dakota and Montana. It ranges from 115 to 150 m in thickness in western Manitoba, to a maximum of ~244 m in central Saskatchewan where it disconformably overlies and obliquely truncates the Prairie Evaporite Formation and Potash members. The group represents a series of cyclical shale-carbonate-evaporite units. The lowest of these cycles is the:
  Dawson Bay Formation, which commences with a basal red shale, known as the Second Red Beds. This basal member comprises 3 to 12 m of mainly red, brown and greenish grey mudstones, the uppermost part of which is a thin dolomitic unit, varying from several to 20 cm in thickness, composed of massive and laminated dolostones, and dolomitic intraclast breccia. The remainder of the overlying Dawson Bay Formation is 40 to 50 m thick, thinning westward. It commences with a basal dolomitic mudstone, overlain by microcrystalline to cryptocrystalline, fossiliferous limestone with hardgrounds in the lower half of the carbonate sequence, followed by an agillaceous carbonate that is, in turn, succeeded by microcrystalline to sucrosic, bituminous limestones, locally reefoid. These comprise 4 members, while the central upper part of the unit is occupied by an additional 0 to 19 m of halite, the Hubbard Salt/Evaporite.
  The Hubbard Salt may also be overlain by a second evaporitic unit, the Davidson Evaporite which is composed of two halite beds separated by an anhydrite bed. The Hubbard Salt and Davidson Evaporite, where present form a seal that prevents water and brine in the aquifers of the overlying Mesozoic sands from flowing into mine workings in the Prairie Evaporite. Their absence implies dissolution and removal processes have been active.
  Souris River Formation, a further series of cyclical shale-carbonate-evaporite beds that are generally similar to the Dawson Bay beds, but with cycles becoming thinner and less well-developed towards the top of the unit. In outcrop, it has a transitional, conformable contact with the underlying Dawson Bay Formation, and commences with a sequence of red and green calcareous shales, fossiliferous argillaceous limestone, cryptocrystalline and fragmental fossiliferous limestone, and yellowish brown dolomite and dolomitic limestone. These are locally overlain by, dolostone and limestone. Within the sub-surface, and there are also anhydrite and halite beds included in the sequence. The Souris River Formation was deposited between 387.7 and 372.2 Ma in the Frasnian of the Middle Devonian and is distributed throughout the Williston Basin. It is generally ~120 m thick, reaching a maximum of near ~200 m in the Saskatoon area.
Saskatchewan Group, which is found throughout the Elk Point Basin, except around its edges, where it has undergone post-Mid Carboniferous erosion. It is predominantly composed of carbonates, with thin evaporites that exhibit cyclic sedimentation. These cycles are of variable thickness and are often incomplete. A complete cycle sequence would comprise, in ascending order: a thin dolomite (commonly with rolled mudstone clasts) →; fossiliferous limestone → thin dolostone → algal stromatolites → anhydrite → halite → and thin dolomitic mudstone. It has been divided into the:
  Duperow Formation, which varies in thickness in Canada, from <120 m in SW Manitoba, to ~300 m in westernmost Saskatchewan. Southward the unit lenses out in SW North Dakota. North and east of the margin of the zone of Birdbear cover (i.e., the latitude of Saskatoon), the unit thins due to post-Mid Carboniferous erosion. It was emplaced between 385.3 and 374.5 Ma in the Frasnian, and is composed of pale coloured limestone and dolostone, with blue-grey anhydrite, argillaceous dolostone and local development of four halite units. Cyclic sedimentation is recognised, with the local development of up to 27 cycles. The upper contact with the overlying carbonates of the Birdbear Formation is conformable or gently dis-conformable.
  Birdbear Formation, which was also deposited during the Frasnian, and averages ~30 to 45 m in thickness. It comprises a lower member of predominantly non-argillaceous limestones and dolomites, and an upper member of mainly dolostone with interbedded evaporites. Near the Saskatchewan-Alberta border the lower Birdbear comprises argillaceous carbonates. Carbonates are generally yellowish brown and crypto- to micro-crystalline, with sparse faunal contents, except for the upper part of the lower member.

UPPER DEVONIAN to LOWER CARBONIFEROUS

  Hiatus and/or non-preserved sequence in east-central Saskatchewan. Elsewhere it includes the:
Three Forks Group, of Famennian to Kinderhookian age, deposited between 372.2 and 348.9 Ma, with a thickness that varies from 35 to 80 m. It conformably overlies carbonates of the Saskatchewan Group, and is sub-divided into the:
  Torquay Formation, deposited between 372.2 and 358.9 Ma in the Famennian, it is consistently 45 to 50 m thick, except in southwestern Saskatchewan, where it reaches a maximum of 65 m, whilst in southeastern Saskatchewan, it is locally reduced to 20 m. It is composed of grey and green to red and brown dolostone and shale, with lesser anhydrite. Some brecciated fragments of dolostone are found scattered in the mudstone. Colour ranges from greys and greens to reds and browns, depending on the degree of oxidation of the sedimentary rocks.
  Big Valley Formation, which averages 15 to 20 m in thickness in southwestern Saskatchewan, and is composed of grey, tan and brown micritic limestone, locally bioclastic and commonly fossiliferous. The limestones are variably argillaceous, with interbeds of grey and green shale increasing towards SE Alberta.
  Bakken Formation, of Kinderhookian age, deposited between 359.2 and 348 Ma, and varying from 3 to 40 m in thickness. It is a tripartite unit composed of a medial calcite, or rarely dolomite cemented fine, quartzose sandstone and siltstone with ripples, cross-bedding and flaser bedding, as well as interlamination of sandstone and claystone and local occurrences of oolitic calcarenite. The upper and lower members are black, organic rich shales.

EARLY CARBONIFEROUS to LOWER TRIASSIC

  Hiatus and/or non-preserved sequence in east-central and west-central Saskatchewan. In southwest Saskatchewan, this period includes the:
Madison Group, deposited between 359.2 and 318.1 Ma in the Mississippian of the Lower Carboniferous as a 457 to 640 m thick limestone sequence that contains argillaceous limestones and calcareous shales in the lower part, and massive brecciated limestone zones in the upper part. It is best developed to the south in southwestern Montana and Idaho and eastward in central Montana, but thins progressively by truncation towards zero edges in Saskatchewan beween Regina and Saskatoon. In southern Saskatchewan it has been subdivided into the:
  Lodgepole Formation, or Souris Valley Beds, which are 122 to 176 m thick, and were deposited between 359.2 and 348 Ma in the Kinderhookian. It is a dark grey, sparsely fossiliferous, thin bedded basin-type sequence of argillaceous limestones, calcareous shales and chert. To the east and north, it loses its argillaceous nature and becomes more shelf-like.
  Mission Canyon Formation, deposited between 352.1 and 340 Ma in the Osagian, this unit is ~100 m thick, and generally consists of white to cream limestone, mainly bioclastic, pseudo-oolitic and oolitic calcarenites, in part dolomitised. It locally contains thin anhydrite beds. In southern Saskatchewan it is divided into the i). 49 to 80 m thick Tilston Beds, which are oolitic-pisolitic and crinoidal grainstones and packstones, with a facies change to dense, often cherty, finely crystalline limestones that in places are dolomitised in the west; ii). the 65 to 123 m thick Frobisher-Alida Beds, composed of fossiliferous-fragmental to algal, oolitic and pisolitic limestones, with patchily distributed lenticular sandstones in the middle, and at least three evaporitic intervals.
  Charles Formation, which was deposited in the Osagian to Meramecian, of the Carboniferous, between 359.2 and 318.1 Ma, conformably overlying the Mission Canyon Formation. It is best developed to the south in Montana, but thins northward toward its erosional limit in southern Saskatchewan, where it is typically ~185 m thick. It has been subdivided into the: i). 49 to 80 m thick Midale Beds, that comprise the lower, up to 10 m thick, Frobisher Evaporite that is a sub-aqueous to supratidal anhydrite, and the upper Midale carbonate that is made up of locally vuggy, oolitic-pisolitic and skeletal grainstones and packstones, as well as dolostones and dolomitised burrow-mottled limestones and wackestones. These are overlain by the ii). 0 to ~45 m thick Ratcliffe Beds, composed of dense dolostones and mudstones, interlayered with three distinctive anhydrite intervals; and iii). the 117 to ~152 m thick Poplar Beds consisting of limestones, argillaceous dolostones and evaporites, primarily anhydrite and evaporitic dolomite, with two, 4.6 to 12 m thick local halite beds.
Big Snowy Group, that in SE Saskatchewan is represented by the Kibbey Formation, a shaly, predominantly brick-red sandstone sequence that is ~45 m thick, overlying the Charles Formation. The group, overall, is best developed in the centre of the basin to the south in Motana, extending as far north as extreme south-central Saskatchewan where only the basal Kibbey Formation survives.

MID TRIASSIC to MID JURASSIC

Watrous Formation, which was deposited between 251 and 145 Ma, through the Triassic into the early Jurassic. It may be divided into a lower argillaceous and an upper anhydrite member. Both are found across southern Saskatchewan, south of around Saskatoon. The i). Lower Member is typified by red shales and mudstones, frequently variegated with green, that are thinly and irregularly interbedded with laminated anhydrite and contain anhydrite patches, blebs and inclusions. The ii). Upper Member is a bed of massive anhydrite that is several metres thick that laps over the lower units along the edge of the Watrous area of distribution. The lower member infills irregularities in the sub Mesozoic erosional surface and varies abruptly in thickness. The combined thickness of both units ranges from 110 m along the border with North Dakota to zero at the erosional margin. Around Saskatoon, in the north it is only found as isolated remnants, sandwiched between unconformable contacts, although thicker sections are preserved around Regina to its south.

MID to UPPER JURASSIC

  Hiatus to non-preserved sequence in eastern Saskatchewan. In south and southeastern around Regina and further south in Saskatchewan, this sequence comprises:
Lower and Upper Gravelbourg Formation, deposited in the Middle Jurassic Bajocian, between 171.6 and 167.7 Ma. It is best developed in southeastern Sasktchewan where it is >60 m thick in the basin centre, thinning westward into Alberta onto the flank of the Sweetgrass Arch, and eastward toward the basin margin in southwestern Manitoba and eastern central Saskatchewan. It is divided into: i). a Lower Member which comprises buff to tan dolomitic limestone with green shale partings; and ii). an Upper Member that is mostly composed of dark greenish grey fossiliferous shale which, in southeastern Saskatchewan, is interbedded with minor amounts of quartzose sand and argillaceous limestone.
Lower and Upper Shaunavon Formation, which together are 42 to 48 m thick, and were deposited between 167.7 and 164.7 Ma in the Bathonian of the late Middle Jurassic. It grades down into the Gravelbourg Formation, and was deposited across the basin and into Montana and North Dakota. The i). Lower Member is a generally massive, buff to tan, earthy, micro-crystalline limestone, with a thickness of up to 32 m. The ii). Upper Member comprises grey, very fine- to fine-grained, calcite-cemented quartzose sandstone, blue-grey and greg-green quartz sand and nucleated oolitic limestone, shell calcarenite and calcirudite, coquina and argillaceous limestone; as well as tan dolostone, and marlstone, and tan to green to grey and black shales.
Vanguard Group, which is found in southwestern Saskatchewan, south of Regina where it disconformably overlies the Shaunavon Formation and is severely truncated below the Cretaceous Mannville Group. It was deposited during the Callovian to Oxfordian of the Upper Jurassic between 164.7 and 155.6 Ma, and varies from 0 to 180 m in thickness. It dominantly comprises a grey-green, variably calcareous shale, split by a central unit of glauconitic, calcareous, finely-bedded, fine-grained quartzose sandstone.

CRETACEOUS

Mannville Group, deposited between 145.5 and 99.6 Ma in the Lower Cretaceous, and is generally composed of ~145 m of interbedded non-marine sands and shales, overlain by a thin, non-marine calcareous member which is, in turn, followed by marine shales, glauconitic sands and nonmarine salt-and-pepper sands in southern and central Alberta. North of Regina it has been divided into the lower Cantuar Formation, mostly composed of mudstone indurated arenite that varies from white-kaolinitic to grey to black-carbonaceous mudstone; and the upper Pense Formation shale.   This sequence is disconformably overlain by the:
Colorado Group, of Upper Cretaceous 108.8 to 83.5 Ma Middle Albian to Santonian age, comprising an ~150 to 1000 m sequence that is dominantly argillaceous, but includes subordinate shaly conglomerate, sandstone and siltstone, as well as minor shaly chalk, chalky limestone, bentonite, pelecypod coquinas, accumulations of fish-skeletal debris, nodular phosphorite and concretionary layers of calcite, siderite and pyrite. In Canada, it has been divided into an upper, calcareous and a lower, noncalcareous section, separated by the base of the lower of two widespread marker units characterised by abundant white flakes of coccolithic debris.
Bearpaw Formation, deposited between 83.5 and 65.5 Ma in the Campanian to Maastrichtian of the Upper Cretaceous, above the Colorado Group and is widely distributed through southern Alberta and southwestern Saskatchewan. This sequence wedges out to the north and west and varies from ~350 m to ~200 m. It is composed of dark grey clays, claystones, silty claystones, shales, silts and siltstones, with subordinate brownish grey silty sands, sands and sandstones and numerous concretionary beds and thin beds of bentonite.

CENOZOIC

Pleistocene glacial till that is up to 100 m thick.

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POTASH MEMBERS OF THE PRAIRIE EVAPORITE FORMATION

  The following is primarily based on Cocker, M.D., Orris, G.J., Dunlap, P., Yang, C., and Bliss, J.D., 2023, Geology and undiscovered resource assessment of the potash-bearing, Middle Devonian (Givetian), Prairie Evaporite, Elk Point Basin, Canada and United States: U.S. Geological Survey Scientific Investigations Report 2010–5090–CC, 145 p. and data files, https://doi.org/10.3133/sir20105090cc.
NOTE: See the Geological Setting section above for the setting and an introduction to the distribution of these potash members.
The principal potash bearing members and inter-member units within the Prairie Evaporite Formation are as follows, from the base:

Esterhazy Member
  This is the lowest potash-bearing member of the Prairie Evaporite Formation, and the second most important potash producer to date, mainly in the southern part of the Saskatchewan sub-basin to the south and SE, where depth, grade, salt-back and sylvinite thickness are favorable for conventional underground and solution mining. The principal mines exploiting this member include Rocanville, Rocanville West and Esterhazy K1, K2 and K3, whilst the Triton (or Leech Lake) and Bredenbury potash projects NW of Esterhazy may eventually become conventional underground mines within the member. In addition it is exploited by the Belle Plaine, Bethune/Legacy and Russell-St Lazare solution mines and is planned to be mined by the Milestone, Albany, Broadview and Southey solution mining projects.
  The Esterhazy Member dips to the SW at 3 to 7 m/km, and the depth to it's top ranges from ~840 m along the NE edge of the basin, to 2756 m in southeastern Saskatchewan (Yang et al., 2009) and to >3 km in North Dakota and Montana (Great Northern Railway Company, 1965; Anderson and Swinehart, 1979; Kruger, 2014). It has a mean thickness of 9 m in the NE, increasing to >15 m between Regina and the Belle Plaine Mine to the SW. To the SE it may be as thick as 26 m, but thins to between 1.52 and 4.2 m further east in Manitoba.
  Available information indicates this member comprises several beds of sylvinite, or locally carnallitite, separated by halite interbeds and clay seams (Holter, 1969; Moore et al., 2010; Rauche et al., 2016). In the Wynyard area (40 km SE to ESE of Jansen), three distinct high-grade sylvite-bearing salt horizons are separated by lower grade sylvite-bearing salt and are grouped into two packages, the Esterhazy Zone 1 and Zone 2 (Rauche et al., 2016). In the Esterhazy K1 Mine, the medium to high grade lower beds (beds 40 to 50) of the Esterhazy Member form the 2.6 m thick mining zone. Above this zone, there are a series of low to medium grade sylvite-bearing halite beds (beds 1 to 35), distributed over an interval of 6.4 m (Keys and Wright, 1966).
  Potash grades for conventional underground mines in the Esterhazy Member range from 22 to 24.5% K2O equivalent, whilst for solution mining, they vary from 10.4 to 22%. Lower grades in the latter account for the inclusion of lower grade interbeds above and below, and possibly carnallitic material in the leached interval. In sections of the Legacy, now Bethune, Mine (to the SW, 60 km NW of Regina), the Esterhazy Member is characterised by being typically coarser grained, with 2 to 3 cm crystals (Hardy et al., 2009).
  Compared to the other potash members of the Prairie Evaporite Formation, the Esterhazy Member contains the least insoluble material, with a mean of 1.87% disseminated insoluble minerals. The carnallite content is variable (Stoner and Mackintosh, 2012), but overall is the lowest in the Prairie Evaporite Formation, occurring as interstitial, reddish-orange amorphous crystal masses, commonly rimming sylvite (Myers et al., 2017), or as carnallitite in the Esterhazy K1 mine (Keys and Wright, 1966). Carnallite grades are mostly <6% with higher concentrations, of as much as 14%, reported in drilling on the NE margin of the basin. The carnallite-bearing salt in this area, and in the Esterhazy K1 mine, is thought to represent primary carnallitite that has not been altered to secondary sylvite (Keys and Wright, 1966; Hambley et al., 2011). Alteration of the upper sections of the carnallite zone has resulted in an upper sylvite band and underlying carnallitite along the top of the ore zone. There is a strong correlation between the thickness of carnallitite and that of the total Esterhazy Member at Esterhazy K1 (r2=0.9977).
  The base of the Esterhazy Member is not well defined due to a paucity of drilling. In places, potash-bearing salt containing carnallite is separated from the defined base of the Esterhazy Member by ~10 m. Elsewhere drilling indicates carnallitite may extend 15 m below the base of the Esterhazy Member. The lowermost drilled carnallite may be considered part of the Esterhazy Member, or could be part of a separate, earlier potash-bearing salt unit. It has been suggested that carnallite began to precipitate prior to sylvinite below the presently defined base of the Esterhazy Member in the Elk Point Basin or that sylvinite is an alteration product formed from the underlying carnallite (Cocker et al., 2023).
  The total cumulative production from the Esterhazy Member to November 2019 has been 120 Mt of K2O) equivalent, whilst past production + Ore Reserves are 15.32 Gt of K2O) equivalent (Cocker et al., 2923).

Interbed 2
  This is an informal name for a section of variably potash-bearing salt between the Esterhazy and Belle Plaine members, and includes the White Bear Member. It is predominantly composed of halite, with disseminated sylvite and carnallite, plus generally thin, sylvite- and carnallite-bearing halite beds and halite (Holter, 1969; Hardy et al., 2009, 2010, 2013). It is reported to have thicknesses that vary from 11.10 to 43 m on the northern edge of the Saskatchewan Sub-basin (Holter, 1969), with grades ranging from 1.60 to 5.10 percent K2O equivalent. It has generally low carnallite contents of from 0.36 to 0.57%. The insoluble mineral content is also low, between 1.23 and 4.65% (Hardy et al., 2009, 2013). This unit may potentially be included in future solution mining operations targeting the the Esterhazy and/or Belle Plaine members.

White Bear Member
  This member is not an economic source of potash due to its relatively thin development, generally lower potash grade and greater depths than the Patience Lake and Belle Plaine Members. In some petroleum wells, it occurs as a single interval of potash-bearing salt, and is logged as part of Interbed 2. In other wells, intervals with several potash-rich strata are collectively called the White Bear Member (e.g., Hardy et al., 2009). In Manitoba, an upper potash intercept has been informally described as the Pink Panther Potash Bed and a lower intersection as the White Bear Potash Member, separated by intervals containing lesser amounts of potash. The actual extent, thickness, and potash grade of this member appear not to be as consistent as those of the other members.
  In Saskatchewan, the White Bear Member ranges from 1 to 10 m in thickness, with a mean of 4 m. It is thickest in southeastern Saskatchewan (Worsley and Fuzesy, 1979; Yang et al., 2009). In Manitoba, it ranges from 1.52 to 2.5 m (Bannatyne, 1983). It has been shown to also extend into North Dakota, where it is as thick as 10 m in the northern part of the state. The greater thicknesses in SE Saskatchewan and North Dakota may reflect the presence of two sub-members, rather than just one interval of potash-bearing salt. Yang et al. (2009) describe the member as interbedded low-grade sylvite beds, halite beds and clay seams. Kruger (2014, 2016) includes carnallite in his estimates of its composition. In Saskatchewan, well assays range from 3.31 to 16.13% K2O equivalent over intervals of 1 to 15 m. An exploration drill hole in North Dakota intersected 1.57 m of the White Bear Member with a K2O equivalent grade of 3.31% at a depth of 2685 m (Sirius Minerals, Plc., 2011). The thickness of the salt-back for this member is measured to the base of the overlying Belle Plaine Member or Patience Lake Member. If these members are absent, the salt-back may be measured to the top of the Prairie Evaporite, and have a thickness of as much as 54 m (Yang et al., 2009).
  There has been no production from the White Bear Member to November 2019, although estimated remaining Ore Reserves are 34 Gt of K2O) equivalent (Cocker et al., 2923).

Belle Plaine Member
  This is the third most productive unit of the Prairie Evaporite Formation. It is present at the Belle Plaine, Bethune (previously Legacy), Esterhazy and Rocanville operations in the south, and is only mined by solution at the former two, while being uneconomic at the latter pair, which are conventional mines. Bethune is 25 km NNW of the Bell Plaine Mine in the Regina area. It is only poorly developed to the north at Vanscoy, Cory, Allan and Colonsay where it is not mined, but is ~18 m thick at Lanigan although not economically mineable due to grade. It is planned to be extracted from the Milestone, Albany, Tugaske and Southey solution mining projects, should they come into production. The member has also been evaluated as a possible solution mining source of potash at the Wynyard project, which is near Quill Lake, and 40 km SE to ESE of Jansen (Rauche et al., 2016), and at a number of other projects.
  The mineralogy, grade, depth and underground temperatures in the southern and southwestern parts of the Elk Point Basin are regarded as favorable for solution mining of this Member. It's mineralogy is predominantly sylvite, halite and insoluble minerals, which are generally similar to the other potash members of the Prairie Evaporite, although it has locally higher concentrations of carnallite (Holter, 1969). The mean insoluble mineral content is >4.67%, which is greater than that in the Esterhazy Member.
  The overall mean thickness of the Belle Plaine Member is 7 m, although it may be as much as 23 m to the NE of Saskatoon (Yang et al., 2009). Where intersected in drilling, there is a strong correlation of carnallitite thickness to the total member thickness (r2=0.9990). The variation in thickness of the Belle Plaine Member may be due to differences in carnallite content, or to the variations in thickness of sub-members.
  The Belle Plaine Member occurs either as a single continuous, but variable zone of potash mineralisation, as at the Bethune/Legacy Mine area (Hardy et al., 2009), or locally as two sub-members separated by halite or lower grade potash-bearing salt, as at Jansen and Wynyard (Halabura and Gebhardt, 2006; Lomas, 2007, Rauche et al., 2012). At Vanguard (which includes the Tugaske Project), seven sub-members have been distinguished on the basis of potash grades (Debusschere et al., 2016; Fourie, 2017; Fourie et al., 2018). Locally, subdivision of the member by lithology is not readily obvious (Piché et al., 2011) and is based on potash grades instead. At Wynyard, the upper sub-member is 10 m thick and the lower 5 m (Rauche et al., 2012).
  The solubility of sylvite and hence the efficiency of solution mining and extraction increases with temperature, which, in turn increases with depth. The Belle Plaine Member occurs at depths that range from ~815 m along the northeastern margin of the Saskatchewan sub-basin (Yang et al., 2009) to >3 km in North Dakota and Montana (Great Northern Railway Company, 1965; Anderson and Swinehart, 1979). The Belle Plaine Member dips southwestward at 2 to 7 m/km (Yang et al., 2009). In the Legacy, now Bethune Mine, temperatures range from 40 to 46.7°C (Hardy et al., 2010). In the Milestone Project area, bottom-hole temperatures range from 58 to 65.5°C (Hardy et al., 2013). Temperatures in the Belle Plaine Mine area are regarded as probably similar to those in the Bethune/Legacy and Milestone mines. The thickness of the Belle Plaine Member Salt-Back is commony measured to the base of the Patience Lake Member. Where the latter is absent, the Salt-Back extends to the top of the Prairie Evaporites, and may be as much as 54 m.
  The total cumulative production from the Belle Plaine Member to November 2019 has been 20 Mt of K2O) equivalent, whilst past production + Ore Reserves are 9.71 Gt of K2O) equivalent (Cocker et al., 2923).

Interbed 1
  This is an informal interval of potash-bearing salt located stratigraphically between the top of the Belle Plaine and the base of the Patience Lake members. It is predominantly composed of halite with usually thin sylvite- and carnallite-bearing halite beds and disseminated sylvite and carnallite in halite (Holter, 1969; Hambley et al., 2011; Rauche et al., 2016). This interbed has been reported to have an average thickness of 6.10 m with an average K2O equivalent grade of 3.84%, an average of 0.62% carnallite and 5.01% insoluble minerals (Myers et al., 2017). In the Bethune/Legacy Mine area, this interbed had an average thickness of 5.67 m with an average K2O equivalent grade of 5.67%. The amount of carnallite ranges from 4.50 to 10.99%, with from 4.28 to 9.24% insoluble minerals (Hardy et al., 2009, 2010, 2013). In the Milestone Project area, the average potash grade is 2.98% K2O equivalent across an average thickness of 4.27 m (Hambley et al., 2011; Hardy et al., 2013), with carnallite ranging from 0.24 to 0.79% and the insoluble minerals varying from 3.40 to 12.50%.

Patience Lake Member
  This member is the principal host to mined potash in Saskatchewan, and is, or was mined at Jansen, Allan, Colonsay, Cory, Lanigan, Vanscoy and the original conventional Patience Lake mine. It is also, or is planned to be, exploited by solution mining at Patience Lake, Belle Plaine, Bethune/Legacy, Milestone, Albany, Broadview, Tugaske, Southey and Russell-St. Lazare. The qualities that make it ideal for conventional underground mining include, potash grade, continuity of bedding of both marker clay seams and potash beds, salt-back thickness, mineralogy (mainly as sylvite), and depth to the potash-bearing salt. The physical characteristics of the member are generally similar to those of the underlying members, although one of the key differences is that it contains more insoluble material as disseminations and as thin clay seams, which serve as important markers to visually define the stratigraphy of the unit. The overall mean quantity of insoluble material in the Patience Lake Member is 6.8%, although locally it can be as much as 11.0% (Hardy et al., 2009).
  The Patience Lake Member ranges from 3 to 18 m in thickness, with a mean of 11 m. There is again a close correlation between carnallitite thickness and total member thickness (r2=0.9938).
  In the interval from the Vanscoy Mine in the west, to east of the Jansen Mine in the east, the Patience Lake Member has two principal mineable potash-bearing zones known as as either the Upper and Lower Patience Lake sub-members, or the Lower Layer III (or B Zone) and the Upper Layer IV (or A Zone; Boys, 1990; Moore et al., 2010). Both zones are present at Vanscoy, Cory, Allan and Colonsay, but only the upper is mined. At Allan, the A Zone is ~3.5 m thick and the B Zone 4.9 m. Both are ~5 m thick and mined at Lanigan. Both are also found at the Patience Lake Mine where they are exploited by solution mining, while at Jansen, both are economic over widths of 5 to 6 m each.
  These two layers are separated by banded halite with variable sylvite. The Upper Sub-member contains four potash-bearing salt beds, reflecting cycles of deposition, whilst the Lower Sub-member contains six or seven such cycles (Boys, 1990). Clay seams within the member are traceable from mine to mine across tens to hundreds of kilometres (Boys, 1990; Yang et al., 2009; Moore et al., 2010). Polygonal fractures in the clay seams are interpreted as desiccation cracks formed as a result of sub-aerial exposure and drying up of the brine that formed the underlying potash-bearing layer. Further indicators of sub-aerial exposure and desiccation include wash-out channels, micro-karst pits, and chevron halite textures (Boys, 1990), although chevron halite textures have been interpreted as evidence of deep water deposition (Meijer Drees, 1986).
  The thickness of the uppermost salt of the Prairie Evaporite, that forms the salt-back, is very variable, ranging from 0.1 to 45 m, with a mean of 13 m (Yang et al., 2009). However, the distribution is bimodal with two thickness ranges more probable. The mean of the thicker is 27 m, and 6 m for the thinner salt. The thicker development of the Salt Back is largely found in the southern part of Saskatchewan, mainly south of 50°N (the latitude of Regina). One interpretation of these two Salt-Back populations above the Patience Lake Member is that the thicker may represent parts of two additional evaporite cycles in which the potash-bearing salt was not precipitated or preserved. These may be equivalents of the Mountrail and White Lake Members found in North Dakota, and described below. Depths to the Patience Lake Member vary from ~800 m along the northeastern edge of the Saskatchewan sub-basin to 2713 m in southern Saskatchewan (Yang et al., 2009), and to >3700 m in North Dakota and Montana (Great Northern Railway Company, 1965; Anderson and Swinehart, 1979). The shallower depths to the Patience Lake Member allowed the early development of conventional underground mines. The member dips to the SW at 2 to 6 m/km (Yang et al., 2009).
  The total cumulative production from the Patience Lake Member to November 2019 has been 180 Mt of K2O) equivalent, whilst past production + Ore Reserves are 48.11 Gt of K2O) equivalent (Cocker et al., 2923).

Mountrail and White Lake Members
  These two additional potash members, which are developed above the Patience Lake Member, have only been recognized in North Dakota (Kruger, 2014). They may represent two additional potash-evaporite cycles in the US, but have not been seen in Canada nor been formally described. The Mountrail Member is found between 21 and 44 m above the top of the Patience Lake Member and between 1.8 and 32 m below the upper contact of the Prairie Evaporite (Kruger, 2014). It's maximum recorded thickness is 3.7 m. The White Lake Member is between 9 and 27 m above the top of the Mountrail member with a maximum thickness of 1.8 m (Kruger, 2014). It has been suggested these represent the missing potash cycles lying above the Patience Lake Member, as suggested by the occurrence of locally anomalous thick sections of salt-back above that member, as described above. Because these units are 30 m or more above the Patience Lake Member, they may have been deposited in Canada and Montana, but subsequently removed by surface or subsurface dissolution, erosion or may have never been deposited there at all.

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MINERALOGY OF THE POTASH MEMBERS

  The evaporite mineralogy of the Prairie Evaporite Formation is relatively simple. In addition to sylvite, carnallite and halite, and the potassium-bearing minerals polyhalite and leonite, the insoluble minerals and materials such as anhydrite, calcite, chlorite, dolomite, hematite, feldspars, goethite, gypsum, illite, magnesite, micas, pyrite, quartz, smectites, and hydrocarbons have been recognised in the upper part of the Prairie Evaporite (Gorrell and Alderman, 1968; Boys, 1990). The occurrence of the principal minerals is as follows:
• Halite - NaCl, which occurs as <0.63 to >100 mm anhedral to euhedral crystals, either in essentially monomineralic salt layers or in mixed intergrowths with sylvite or carnallite (Holter, 1969; Yang et al., 2009). The crystal size decreases upward in the potash members and the halite interbeds (Klingspor, 1966; Holter, 1969). Chevron-type halite crystals (attributed to syn-depositional growth), with long axes oriented perpendicular to bedding, are locally recognised (Wardlaw, 1964; Holter, 1969). The colour of halite varies, from clear, to brown or grey where it dominates, but when associated with sylvite or carnallite, it is clear or cloudy and commonly coated with insoluble minerals (Holter, 1969), but is never coated by red iron insoluble minerals (Yang et al., 2009). Blue halite is observed locally (McIntosh, 1967; Holter, 1969).
• Sylvite - KCl occurs as 6.3 to 35 mm anhedral to euhedral crystals (Holter, 1969; Yang et al., 2009). It is intergrown with halite and disseminated insoluble minerals to form the hybrid rock sylvinite. Sylvite crystals vary in colour from white to pink to light orange, and may be clear to cloudy. Zoning parallel to crystal outlines is locally observed. The zoning commonly takes the form of red rims, which are attributed to goethite and hematite. Cleavages of the few documented rare sylvite chevron crystals were parallel to bedding (Holter, 1969). The maximum sylvite content of sylvinite measured is ~48 wt.% over a number of 15.30 m intervals in the Patience Lake and Belle Plaine Members, and as much as 66 wt.% in a 1.8 m interval in the Esterhazy Member (Yang and Love, 2015; Hardy and Halabura, 2008).
• Carnallite - KMgCl3•6H2O, which is commonly intergrown with halite to form the hybrid rock carnallitite. The carnallite crystals are subhedral to anhedral, with grain sizes that range from <0.63 to >100 mm, similar to that of the halite with which they are intergrown. The carnallite varies in colour from clear white to red and translucent black. Colour zoning patterns include clear or black carnallite cores with red rims, or red cores with black rims. It also commonly contains plates of hematite and goethite fibres (Wardlaw, 1968; Holter, 1969). Particularly in the lower members of the upper Prairie Evaporite Formation, the sylvinite ore contains: i). narrow, vertical to subvertical fractures filled with secondary white or red carnallite which may also locally replace sylvite and halite (Fuzesy, 1982); and ii). large, 1 to 6 m diameter, predominantly colourless to white and yellow, carnallite-rich pods (McIntosh and Wardlaw, 1968; Fuzesy, 1983; Koehler, 1997).
  The amount of carnallite in a core sample interval is normally calculated by multiplying the Mg in percent by a factor of 11.4. If the mineralised interval contains ≥6% carnallite or 0.5% magnesium, it is avoided in Saskatchewan mining operations (Hambley and others, 2011). In conventional underground mines, carnallite-rich areas have a tendency to absorb moisture from the atmosphere, causing dissolution of the carnallite and thereby weakening the supporting pillars or walls. In addition, grades of carnallitic mineralisation is generally lower than that of sylvite ore, as well as being more difficult and expensive to process (Garrett, 1996). In solution mining operations, carnallite dissolves more readily than sylvite because the magnesium in carnallite substantially reduces potassium saturation levels in aqueous solution, and as a consequence reduces the efficiency of cavern dissolution and potash recovery (Hambley et al., 2011).
• Insoluble Minerals - There is an upward progression and zonation of insoluble minerals within the Prairie Evaporite Formation. Below the Shell Lake Member, in the potash deficient Whitkow Member, the insoluble minerals are predominantly dolomite and anhydrite. Within the Shell Lake Member itself, the anhydrite is normally light to dark grey or a mottled grey brown and finely crystalline. It occurs in halite beds as disseminations and lenses, thin interbeds, or massive beds that are ~1 m thick (Holter, 1969). Locally, within sections of the lower Prairie Evaporite, thin 1 cm bands of anhydrite alternate with 2 to 10 cm thick layers of halite (Wardlaw and Schwerdtner, 1966). Dolomite, which varies from fine grained to microcrystalline, is usually associated with the anhydrite which occurs as thin laminations to thick beds or as fine disseminations (Holter, 1969).
  In the upper, potash-bearing part of the Prairie Evaporite Formation, anhydrite, dolomite and the other insoluble minerals are generally not abundant and are only minor components, mainly occurring in thin clay seams. The principal clay minerals are illite, chlorite, septechlorite, sepiolite, smectite, mixed layer chlorite/smectite, corrensite and traces of vermiculite (Boys, 1990). The concentration of this insoluble assemblage increases upward from the base to the top of individual potash cycles, whilst there is also a progressive increase upward from one cycle to the next over the interval from the Esterhazy to the Patience Lake members. Clay seams mark the top of the mining interval in the Patience Lake Member, separating high grade potash from overlying low grade halite waste. Although resulting in dilution, these clay seams are removed during conventional mining, as they commonly are a source of weakness in the roof/back of the mine opening (Jones and Prugger, 1982; Boys, 1990). Clays within the ore may be deleterious, reacting with the reagents employed to process the potash. However, these seams are generally too minor a dilutant to be a detrimental. In solution mining, insoluble minerals are left underground and do not affect ore processing (Hambley et al., 2015; Rauche, 2015).
  Other insoluble minerals and materials identified in the upper part of the Prairie Evaporite include chlorite, hematite, feldspars, quartz, goethite, magnesite, pyrite, quartz and hydrocarbons (Gorrell and Alderman, 1968; Boys, 1990).
• Textures and Paragenesis - only a few primary textures are evident in the salt beds, whilst none are observed in the sulphate beds. This paucity of primary textures has been taken to indicate most of the evaporite minerals have been recrystallised subsequent to the initial precipitation (Holter, 1969; Meijer Drees, 1986). Available petrological and geochemical data suggest sylvite was replaced by both secondary sylvite and carnallite, halite was replaced by carnallite, and carnallite was replaced by sylvite (Streeton, 1967; Holter, 1969).

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GEOLOGIC ANOMALIES

  The stratigraphy of the potash-bearing beds of the Middle Devonian Prairie Evaporite Formation is very consistent throughout much of Saskatchewan and portions of neighbouring Manitoba, North Dakota, and northeast Montana. Generally, the mineralisation within the Elk Point Basin is flat-lying, with individual clay seams and sylvinite-bearing intervals correlatable over distances of hundreds of kilometres. Consequently any disturbance that affects the lateral continuity, character or preserved thickness of the potash-bearing beds is considered an anomaly, and may represent a zone that is potentially unsuitable for mining. This includes the leaching of evaporites and removal of potential resources or physical disruption. These may substantially influence the accuracy of resource estimations, particularly those based on such widely spaced drilling as is the practice in the belt. Such irregularities may also provide a breach in the salt back which forms a seal against the ingress of water from aquifers above, thus increasing the susceptibility to major mine flooding events and other water problems. Three main types of such geologic anomalies may occur within the mineralised beds. These range from local to regional features that may extend over areas of up to several tens of square kilometres.
• A dissolution and collapse anomaly, where the Prairie Evaporite Formation sequence has been removed by dissolution, and overlying barren material dropped into the resulting space. These anomalies may be local, i.e. <1 km2, or may extend over several, up to tens of square kilometres, affecting the entire thickness of the Prairie Evaporite Formation. Also, whilst halite beds commonly form a stratigraphic seal impeding the passage of fluids in sedimentary systems, the presence of structural disturbances such as folds, faults and joints may allow the incipient ingress of water that then facilitates the dissolution of evaporites and initiate a geologic anomaly and collapse.
• A leach/depletion, replacement anomaly and formation of halite zones, where the more soluble sylvite has been selectively removed from the sylvinite bed and replaced by euhedral to subhedral halite. Such anomalies are known as 'salt horses'. Such anomalies described at the Vanscoy Mine are characterised by the partial to complete absence of sylvite in what is otherwise a normal, continuous stratigraphic sequence. These anomalies are typically local, ranging from a few, to as much as 400 m in diameter. They can also be linear, with widths of >20 m developed over a length of as much as 1600 m (Mackintosh and McVittie 1983).
• A washout anomaly, where a sylvinite bed is replaced or altered to a mass of 5 to 10 mm euhedral to subhedral halite crystals enclosed within a groundmass of finer-grained halite and clay. The clay is typically composed of up to 10 mm intraclasts, as well as a concentration of clay at the top and base of the anomaly. These have been described as salt-filled V- or U-shaped structures which cut across the normal bedded sequence and obliterate the stratigraphy (Mackintosh and McVittie 1983).
  In addition to these localised anomalies, considerable volumes of potash-bearing salt beds have been removed along the eastern edge of the Prairie Evaporite Formation in Manitoba and Saskatchewan (Gorrell and Alderman, 1968; Nicolas, 2016), and the large embayment south of Saskatoon, locally cutting down into underlying carbonate rocks of the Winnipegosis Formation. Localised salt dissolution took place during the Middle and Late Devonian principally in the embayment area south of Saskatoon. During the Late Carboniferous (Mississippian) to Jurassic, salt solution continued in the same area and along the northeastern part of the Prairie Evaporite Formation. Considerable salt solution also occurred from the post-Jurassic through the Pleistocene all along the northeastern edge of the Prairie Evaporite and in the southern embayment (Holter, 1969; Yang et al,, 2009; Nicolas, 2016).
  The Prairie Evaporite Formation is overlain by a series of cyclic Devonian limestones, dolostones and evaporites that make up the Dawson Bay and Souris River Formations of the Manitoba Group, as detailed previously. This group includes two crucial halite beds: i). the Hubbard Salt, the uppermost bed of the Dawson Bay Formation, and ii). the Davidson Evaporite composed of two halite beds separated by an anhydrite bed. Where present, these evaporites form another seal above the salt-back, separating the Prairie Evaporite potash mining horizons from the water and brine aquifers present within the overlying Mesozoic sands. Its absence, especially the halites, implies dissolution and removal processes have been active, so creating a potential head and lateral stability difficulties in a conventional underground mine.

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KEY DEPOSITS OF THE SASKATCHEWAN POTASH BELT

JANSEN

The Jansen Potash Project is located ~11 km south of the township of LeRoy and ~150 km east of the city of Saskatoon in the Province of Saskatchewan, Canada (#Location: 51° 53' 56"N, 104° 42' 53"W).

  The Jansen deposit is hosted within the Elk Point Basin, a large, intracratonic sedimentary basin between the Canadian Shield and the Rockies, and occurs at depths of between 800 and 1050 m below surface, within a largely flat lying to shallowly dipping sequence. The Potash occurs as a gently dipping layer, averaging 3.9 m in thickness, composed of sylvinite, a mixture of sylvite (KCl) and halite (NaCl), which is mixed with variable amounts of disseminated insolubles and clay seams. The KCl content is quoted in terms of potassium oxide (K2O) % equivalence, where the KCl content is 1.583 x %K2O grade.

  The presence of potash in the host sequence was initially indicated in petroleum exploration wells drilled in the 1940s. The first significant exploration specifically for potash in the Jansen area was undertaken in 1952 by the Potash Company of America, followed by Alwinsal Potash of Canada in 1959. Subsequently, Kerr-McGee Oil Industries Inc. was responsible for the main historical exploration effort between September 1962 and October 1965. No further work was undertaken in the area between 1965 and 2005, until a small company, Anglo Minerals Ltd., applied for an extensive area of potash exploration permits surrounding the producing Potash mines in the Saskatoon area, which included the Jansen project area. In September 2005, Anglo Minerals assembled the historical drilling data, mainly that of Kerr-McGee, to calculate a resource estimate on one of its permits, followed by a small 3D seismic survey between October 2005 and March 200 that covered part of the Jansen deposit,. This was followed by a similar drilling data compilation and seismic program on a number of their other titles. In June 2006, Anglo Minerals, by then known as Anglo Potash Ltd., entered into a joint venture with BHP Billiton to further the exploration and development of the Jansen Project. In 2008, BHP Billiton acquired 100% of the shares of Anglo Potash and complete control of the project. In June 2010, BHP Billiton announced an in-situ Mineral Resource of 3.370 Gt @ 25.4% K2O. On 17 August, 2021, BHP Group approved the development of stage 1 of the Jansen Project. Production at Jansen is expected to begin in late 2026 and ramp up to produce ~8.5 Mt of potash per annum.

Deposit Geology and Mineralisation
  The Jansen deposit lies ~900 m below relatively flat, open, prairie type farm land, underlain by >100 metres of glacial till deposits that, in turn, overlies the thick Upper Cretaceous Bearpaw Formation. At Jansen, the Cretaceous sequence is unconformably underlain by Jurassic and Triassic remnants and a thick Palaeozoic succession, predominantly composed of carbonates. The Jansen potash deposit is hosted at the top of the Middle Devonian Prairie Evaporite Formation which conformably overlies the predominantly carbonate layers of Winnipegosis Formation. Two of the main, regionally developed potash bearing members of the Prairie Evaporite Formation are found in the Jansen area, the Patience Lake and Belle Plaine members. The former is further subdivided into Upper and Lower Patience Lake sub-members. The Lower sub-member is the main target at Jansen. As detailed above, mineralisation within these potash layers was deposited in regionally extensive, horizontal layers during the repeated, cyclical evaporation of a shallow, salt pan environment during the Devonian. It occurs as a layered, repetitive sequence of sylvite (KCl) with halite (NaCl) and thin layers of insoluble dolomitic clay seams. Carnallite (KCl•MgCl2•6H2O), which can affect processing and ground stability, occasionally occurs in place of sylvite in these layers. The Lower Patience Lake sub-member averages ~5 m in thickness and is composed of 4 cycles, punctuated by 6 clay seams, identified as seams 401 to 406. Cycle 1 is underlain by seam 401, with an internal seam 402 and upper 403 seam at the base of the second cycle. Seams 404 and 405 are at the base of cycles 3 and 4 respectively, whilst seam 406 is at the top of cycle 4.
  The Prairie Evaporite Formation is overlain by the Devonian Dawson Bay Formation, which includes the Second Red Beds Member and the Dawson Bay carbonates. Approximately 400 metres below the potash layers of the Prairie Evaporite Formation, the Cambrian-Ordovician Winnipeg and Deadwood formations comprises near shore, shallow water coarse to fine marine sands that host a vast deep saline aquifer that is used for brine disposal.
  The mineable Lower Patience Lake member is overlain by a waste halite unit, bound above and below by clay seams 406 and 407, which present a potential geotechnical hazard. The clay seams may weaken the roof/back and necessitate extra ground support or additional cutting, thus increasing the dilution. This has been taken into account in the reserve estimations.
  The mining height for the estimated reserve is variable between 3.7 and 4.4 m.

Reserves and Resources as at 30 June, 2022 were:
  Inferred Mineral Resources - 1.280 Gt @ 25.6% K2O, 7.7% Insolubles, 0.08% MgO.
  Probable Ore Reserves - 1.070 Gt @ 24.9% K2O, 7.5% Insolubles, 0.10% MgO.
 TOTAL Reserve + Resource - 2.350 Gt @ 25.3% K2O, 7.6% Insolubles, 0.09% MgO.
NOTE: Ore Reserves are exclusive of Mineral Resources. Ore Reserves are based on the expected metallurgical recovery of 92% and a break-even grade is 11.6% K2O.

NOTE: Mineral resources are based on the expected metallurgical recovery of 92%.
  Potash or sylvite (KCl) content of the deposit is reported in potassium oxide form (K2O). The conversion from KCl to K2O uses a mineralogical conversion factor of 1.583, e.g., 25.6% K2O grade is equivalent to 40.5% KCl.
  % MgO is used as a measure of carnallite (KCl•MgCl2.6H2O) content where % carnallite equivalent = % MgO x 6.8918.
  Mineral resources tonnages are reported on an in-situ moisture content basis which was estimated to be 0.3%.

  The information in this Jansen summary has been largely drawn from Nemeth, B., Turkekul, O., Sondergaard, J., McKinnon, C., Madsen, D., Shrestha, B., Gauld, G., Dissanayake, M., Failler, M. Ouellet, J. and Lavalin, S.N.C., 2022 - SEC S-K 229.1300 Technical Report Summary, Prefeasibility Study, Jansen Potash Project Saskatchewan, Canada: A technical Report prepared for BHP Group Limited, Collins Street, Melbourne, 165p.

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ALLAN

  The Allan potash mine is located in central Saskatchewan, ~45 km east of the city of Saskatoon (#Location: Allan #2 shaft - 51° 55' 54"N, 104° 4' 19"W).

  Exploration drilling for potash in the Allan area was undertaken during the 1950s and 1960s. The results of this drilling led to the construction of the Allan mine by a consortium of companies that included U.S. Borax, Homestake Potash Company and the Swift Canadian Company in the 1960s, with potash production commencing in April 1968. The mine has run continuously since then to the present (2024). PotashCorp of Saskatchewan acquired a 60% ownership of the Allan mine in 1978 through the purchase of the U. S. Borax and Swift Canadian interests, and became the operator in 1981. In 1990, PotashCorp purchased the remaining 40% interest. As of January 1, 2018, PotashCorp completed an 'Arrangement' with Agrium, resulting in PotashCorp and Agrium both becoming wholly-owned subsidiaries of Nutrien, the newly created parent company.
  Mineable potash at Allan is hosted within the 100 to 200 m thick Prairie Evaporite Formation, which is overlain by ~500 m of Devonian carbonates, ~100 m of Cretaceous sandstone, 400 m of Cretaceous shales, and Pleistocene glacial tills. It is underlain by Devonian carbonates (Fuzesy, 1982). This part of Saskatchewan is characterised by flat-lying and relatively undisturbed Phanerozoic stratigraphy over very large areas, including the host Prairie Evaporite Formation. The Allan mine exploits potash within the Patience Lake Member of the Prairie Evaporite Formation. Other potash members within this formation, as described in the 'Geological Setting' section above, specifically the Esterhazy and the White Bear Members are absent at Allan, whilst the Belle Plaine Potash Member is not well-developed, and hence not mined.
  There are two main potash seams at Allan, namely the A (or Upper) Zone and B (or Lower) Zone within the Patience Lake Member. Whilst some test mining has been undertaken in the B Zone, production is restricted to the A Zone. The ore zone averages ~3.35 m in thickness and is ~1000 m below the surface. It is immediately overlain by an ~12 m thick 'Salt Back' that comprises halite and an ~2.25 m thick Upper A Zone that is not mined. This Salt Back separates the A Zone from the overlying stratigraphy.
  A typical column through the Patience Lake Member, from the base is as follows (after Robertson, 1978):
From below a depth of >1050 m beneath the surface - at least 10 m of footwall halite;   ~5 m of sylvinite - the B Zone;   ~2.5 m of halite - the Intermediate Rock Salt;   ~1.25 m of sylvinite;   ~1.25 m of halite;   ~5 m of sylvinite - the A Zone (of which the Production horizon is the upper 3.25 m);   ~1.25 m of halite - the Salt Beam, bounded above and below by two prominent clay seams;   ~2.25 m of sylvinite - the Upper A Zone;   at least 4 m of halite. The Salt Beam, Upper A Zone and overlying halite represent the Salt Back to the mining operation, which is ~12 m thick. This column, from the footwall halite to the upper halite of the Salt Back, contains at least 24 prominent clay seams.
  Over the three years (2019, 2020, 2021), the average, measured potash ore grade of the mill feed at Allan was 25.1% K2O equivalent. The Allan mine operates as a conventional, underground potash mine. The overall historic extraction ratio at Allan is 33%. Probable Ore reserves are base on a minimum underground sampling and/or drill hole spacing of 1.6 km. The continuity of the mineralised unit between drill intersections is established by 3D seismic. Seismic data are also relied upon to identify collapse structures (geologic anomalies) that must be avoided in the process of mine development since these structures can act as conduits for water ingress to the mine. As a result, isolation pillars or mining buffer zones are left around these anomalous features. This practice reduces the overall mining extraction ratio, but the risk of inflow to mine workings are effectively mitigated.

Reserves and Resources at a mining height of 3.35 m, as at 31 December, 2021
Allan A Zone with an average grade of 24.7% K2O
  Measured Mineral Resource - 1.183 Gt, covering an area of ~13.5 x 18.5 km;
  Indicated Mineral Resource - 2.533 Gt;
  Inferred Mineral Resource - 1.164 Gt;
 Total A Zone Mineral Resource - 4.880 Gt of in situ ore, covering the total mine lease area of 191 km2.
  Proved Ore Reserve - 107 Mt;
  Probable Ore Reserve - 244 Mt;
 Total A Zone Ore Reserve - 351 Mt of recoverable ore at an average grade of 24.7% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Allan B Zone with an average grade of 20.2% K2O
  Measured Mineral Resource - 1.707 Gt;
  Indicated Mineral Resource - 2.545 Gt;
  Inferred Mineral Resource - 1.169 Gt;
 Total B Zone Mineral Resource - 5.421 Gt.
 No Ore Reserve has been calculated for the Allan B Zone.

Total A Zone + B Zone Mineral Resource - 10.301 Gt.

  The information in this Allan summary has been largely drawn from Funk, C., Derkach, J., MacKenzie, L. and Lawlor, J.N., 2022 - Allan Potash Deposit (KL 112R B), Saskatchewan, Canada; an NI 43-101 Technical Report prepared for Nutrien Limited, Saskatoon, Saskatchewan, Canada, 42p.

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COLONSAY

  The Colonsay potash mine is located in central Saskatchewan, ~70 km east of the city of Saskatoon, 24 km east of the Allan Mine, and ~40 km west to WNW of the Lanigan Mine (#Location: 51° 56' 9"N, 105° 45' 53"W).

  The Colonsay operation is a conventional underground mine, hoist and mill that began production in 1969. It was developed by Noranda Mines Potash Divisions and was operated by its wholly owned subsidiary, Central Canada Potash. In 1995, Noranda sold the Colonsay Mine and Mill to the US based Vigoro Corp., which was, in turn, acquired in 1996 by IMC Global Inc. and operated as IMC Potash Colonsay. In January 2004, IMC was merged with the crop nutrition division of Cargill Inc., to form The Mosaic Company who now own and operate the Colonsay Mine. More recently the Colonsay mine has been operated as a 'swing mine' to meet market demands. On 28 January, 2020, the mine was idled and placed in care and maintenance mode. Then, in the third quarter of 2021, it was restarted and ramped up to a production rate of 2.6 Mt @ 26.4% K2O in 2022, before curtailing mining of February 2024, in response to current market conditions.

  As at the neighbouring Allan and Lanigan mines, potash mineralisation is hosted within two potash-bearing members of the upper Prairie Evaporite Formation, namely the Patience Lake and the Belle Plaine members. These members and their setting are described in detail earlier in this record, and locally within the Allan Mine description immediately above. Mining at Colonsay is restricted to one level within the upper portion, or A Zone, of the Patience Lake Member, following well-defined and continuous beds of mineralisation with relatively consistent grades. The sylvinite at Colonsay is characteristically red, stained by the clay seams surrounding the ore bed. Extraction employs continuous miners and a room and pillar mining method.

Reserves and Resources as at 31 December, 2022, were (The Mosaic Company, 2022):
  Inferred Mineral Resource - 977 Mt @ 29% K2O; (No Measured or Indicated Resources calculated)
 Total A Zone Mineral Resource - 977 Mt @ 29% K2O, covering the total mine lease area 191 km2.
  Proved Ore Reserve - 101 Mt @ 25.3% K2O;
  Probable Ore Reserve - 163.0 Mt @ 27.2% K2O;
 Total A Zone Ore Reserve - 264.0 Mt @ 26.5% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Geological information and resource/reserve estimates were drawn from: The Mosaic Company. 2022 - Form 10-K report to the United States Securities and Exchange Commission; 387p.

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CORY

  The Cory potash mine is located in central Saskatchewan, ~7 km west of the city of Saskatoon (#Location: Cory Service shaft - 52° 05' 38"N, 106° 51' 16"W).

  Exploration drilling for potash in the Cory area was undertaken during the 1950s and 1960s. The results of this drilling led to the construction of the Cory mine by a joint venture between Duval Sulphur and the Potash Company of America in the 1960s, with potash production commencing in 1968. The mine has run continuously since then to the present (2024). PotashCorp of Saskatchewan acquired the Cory mine in 1976. A major refurbishment and expansion of the Cory mine was completed in 2013 increasing its capacity of the Cory Mine to 3.0 Mt of finished potash products per year. As of January 1, 2018, PotashCorp completed an 'Arrangement' with Agrium, resulting in PotashCorp and Agrium both becoming wholly-owned subsidiaries of Nutrien, the newly created parent company.
  The geological description of the Cory deposit offered by Funk et al. (2021) is the same as that the same authors gave for the Allan Mine (see above). As at Allan, potash is found in two seams, the A (Upper) Zone and B (Lower) Zone of the Patience Lake Potash Member of the Prairie Evaporite Formation, and, as at Allan, only the A Zone is being mined at Cory. Again, as at Allan, neither the regional Esterhazy nor the White Bear Potash Members are present in the Cory area, and similarly, the Belle Plaine Potash Member is not well-developed, and therefore is not mined.
  Over the three years (2019, 2020, 2021), the average, measured potash ore grade of the mill feed at Cory was 23.8% % K2O equivalent. The average ore grade observed from thousands of in-mine samples collected to the end of December 2020 is 21.9% K2O equivalent, whilst the average ore grade reported from 11 historic surface drillhole intersections, all within the Cory Subsurface Mineral Lease, is 25.5% K2O equivalent. The Cory mine operates as a conventional, underground potash mine. The ore zone averages ~3.35 m in thickness and is ~1010 m below the surface.

Reserves and Resources at a mining height of 3.35 m, as at 31 December, 2020
Cory A Zone with an average grade of 21.9% K2O
  Measured Mineral Resource - 1.056 Gt, covering an area of ~15.75 km diameter;
  Indicated Mineral Resource - 0.612 Gt;
  Inferred Mineral Resource - 1.284 Gt;
 Total A Zone Mineral Resource - 2.952 Gt, covering the total mine lease area of 297 km2.
  Proved Ore Reserve - 73 Mt;
  Probable Ore Reserve - 141 Mt;
 Total A Zone Ore Reserve - 214 Mt at an average grade of 21.9% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Cory B Zone with an average grade of 20.3% K2O
  Measured Mineral Resource - 1.396 Gt;
  Indicated Mineral Resource - 0.613 Gt;
  Inferred Mineral Resource - 1.286 Gt;
 Total B Zone Mineral Resource - 3.295 Gt.
 No Ore Reserve has been calculated for the Cory B Zone.

Total A Zone + B Zone Mineral Resource - 6.247 Gt + A Zone Ore Reserves = 6.461 Gt.

  The information in this Cory summary has been largely drawn from Funk, C., Derkach, J., MacKenzie, L. and Lawlor, J.N., 2021 - Cory Potash Deposit (KL 103C), Saskatchewan, Canada; an NI 43-101 Technical Report prepared for Nutrien Limited, Saskatoon, Saskatchewan, Canada, 42p.

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LANIGAN

  The Lanigan potash mine is located in central Saskatchewan, ~100 km east of the city of Saskatoon (#Location: Lanigan #2 shaft - 51° 51' 14"N, 105° 12' 40"W).

  Exploration drilling for potash in the Lanigan area was undertaken during the 1950s and 1960s. The results of this drilling led to the construction of the Lanigan mine by Alwinsal Potash of Canada Ltd., a consortium of German and French mining and fertiliser companies in the 1960s, with potash production commencing in 1968. The mine has run continuously since then to the present (2024). The operation was acquired in 1976 by the state owned PotashCorp of Saskatchewan. As of 1 January, 2018, PotashCorp, by then privatised, and Agrium, completed an Arrangement to merge and create a new parent entity, Nutrien, of which they were both wholly owned subsidiaries.
  The geological description of the Lanigan deposit offered by Funk et al. (2022) is the same as that the same authors gave for the Allan Mine (see above). As at Allan, potash is found in two seams, the A (Upper) Zone and B (Lower) Zone of the Patience Lake Potash Member of the Prairie Evaporite Formation. However, unlike at Allan and Cory, BOTH the A and B Zones are being mined at Lanigan. The regional Belle Plaine Potash Member is present at Lanigan but is not economically viable, while the Esterhazy Member is poorly developed and is not economically mineable.
  The original Lanigan exploration program to delineate the deposit comprised 12 drill holes spaced at intervals of 1.6 km to 3.4 km. To date (i.e., 2022), 28 holes had been drilled within the Lanigan Lease, although only 20 are used in the average ore grade calculation for the A and B zones. Those holes omitted were regarded as having intersected 'abnormal geology' (geologic anomalies) whereby a normal potash zone could not be delineated. The average ore grade reported from the 20 historic surface drillhole intersections, all within the Lanigan Subsurface Mineral Lease, is 25.4% K2O equivalent for the A Zone and 23.2% K2O equivalent for the B Zone.
  Over the three years (2019, 2020, 2021), the average, measured potash ore grade of the mill feed at Lanigan was 23.2% % K2O equivalent. The average ore grade observed from thousands of in-mine samples collected to the end of December 2020 is 24.3% K2O equivalent for the A Zone and 20.2% K2O equivalent for the B Zone. The Lanigan mine operates as a conventional, underground potash mine. The optimum ore zone thicknesses are 3.66 m in A Zone, and 4.88 m in B Zone. The A Zone is ~990 m below the surface. Salt cover from the top of the A Zone mining horizon to the overlying units of the Dawson Bay Formation is ~7 m thick, whilst salt cover from the top of the B Zone mining horizon to overlying units is ~14 m thick.

Reserves and Resources at a mining height of 3.66 m in A Zone and 4.88 m in B Zone, as at 31 December, 2021
Lanigan A Zone with an average grade of 24.3% K2O
  Measured Mineral Resource - 2.299 Gt;
  Indicated Mineral Resource - 1.458 Gt;
  Inferred Mineral Resource - 0.348 Gt;
 Total A Zone Mineral Resource - 4.105 Gt, covering the total mine lease area of 563.28 km2.
  Proved Ore Reserve - 52 Mt;
  Probable Ore Reserve - 194 Mt;
 Total A Zone Ore Reserve - 246 Mt at an average grade of 21.9% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Lanigan B Zone with an average grade of 20.2% K2O
  Measured Mineral Resource - 2.912 Gt;
  Indicated Mineral Resource - 1.926 Gt;
  Inferred Mineral Resource - 0.238 Gt;
 Total B Zone Mineral Resource - 3.295 Gt.
  Proved Ore Reserve - 82 Mt;
  Probable Ore Reserve - 238 Mt;
 Total B Zone Ore Reserve - 320 Mt at an average grade of 21.9% K2O.

Total A Zone + B Zone Mineral Resources + Ore Reserves - 9.403 Gt .

  The information in this Lanigan summary has been largely drawn from Funk, C., Derkach, J., MacKenzie, L. and Lawlor, J.N., 2022 - Lanigan Potash Deposit (KLSA 001C), Saskatchewan, Canada; an NI 43-101 Technical Report prepared for Nutrien Limited, Saskatoon, Saskatchewan, Canada, 42p.

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VANSKOY

The Vanscoy potash mine is located in central Saskatchewan, ~26 kilometers west of the city of Saskatoon (#Location: Vanskoy Service shaft - 52° 00' 30"N, 107° 5' 36"W).
Vascoy intersection

  Exploration drilling for potash in the Vanskoy area was undertaken during the 1950s and 1960s. The results of this drilling led to the construction of the Lanigan mine by Cominco Ltd in the 1960s, with potash production commencing in April 1969. With the exception of the 1970 flooding inflow, which halted production for two years, the mine has run continuously since then to the present (2024). In 1993, Cominco Fertilizers Ltd. was formed as an entity separate from Cominco Ltd. In 1995, Cominco transferred its interest in Cominco Fertilizers Ltd. to a new entity, Agrium Inc. As of 1 January, 2018, Agrium completed an Arrangement with PotashCorp of Saskatchewan to merge and create a new parent company, Nutrien, of which they were both wholly owned subsidiaries.
  The geological description of the Vanscoy deposit offered by Funk et al. (2021) is the same as that the same authors gave for the Allan Mine (see above). As at Allan, potash is found in two seams, the A (Upper) Zone and B (Lower) Zone of the Patience Lake Potash Member of the Prairie Evaporite Formation, and, as at Allan, only the A Zone is being mined at Vanscoy. No test mining had been undertaken in the B Zone to 2021. Again, as at Allan, neither the regional Esterhazy nor the White Bear Potash Members are present in the Vanscoy area, and similarly, the Belle Plaine Potash Member is not well-developed, and therefore is not mined.
  The average ore grade reported from the 36 historic surface drillhole intersections, all within the Vanscoy Subsurface Mineral Lease, is 24.9% K2O equivalent for the A Zone.
  Over the three years (2018, 2019, 2020), the average, measured potash ore grade of the mill feed at Vanscoy was 25.6% % K2O equivalent. The average ore grade observed from thousands of in-mine samples collected to the end of December 2020 is is 24.2% K2O equivalent for the A Zone. The Vanscoy mine operates as a conventional, underground potash mine. The A Zone, which is ~3.35 m thick at Vanscoy, occurs near the top of the Prairie Evaporite Formation, at ~1000 to 1120 m below surface. Salt cover from the top of the A Zone mining horizon to overlying units of the Dawson Bay Formation is ~12 m thick.

Reserves and Resources at a mining height of 3.35 m, as at 31 December, 2020
Vanscoy A Zone with an average grade of 24.2% K2O
  Measured Mineral Resource - 1.957 Gt, covering an area of ~350 km2;
  Indicated Mineral Resource - 1.850 Gt;
  Inferred Mineral Resource - 0.932 Gt;
 Total A Zone Mineral Resource - 4.757 Gt, covering the total mine lease area of 820 km2.
  Proved Ore Reserve - 183 Mt;
  Probable Ore Reserve - 326 Mt;
 Total A Zone Ore Reserve - 509 Mt at an average grade of 24.2% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Vanscoy B Zone with an average grade of 20.3% K2O
  Measured Mineral Resource - 2.669 Gt;
  Indicated Mineral Resource - 1.853 Gt;
  Inferred Mineral Resource - 0.933 Gt;
 Total B Zone Mineral Resource - 5.455 Gt.
 No Ore Reserve has been calculated for the Vanscoy B Zone.

Total A Zone + B Zone Mineral Resource - 10.212 Gt + A Zone Ore Reserve = 10.721 Gt.

  The information in this Lanigan summary has been largely drawn from Funk, C., Derkach, J., Lawlor, J.N. and MacKenzie, L., 2021 - Vanskoy Potash Deposit (KL114C), Saskatchewan, Canada; an NI 43-101 Technical Report prepared for Nutrien Limited, Saskatoon, Saskatchewan, Canada, 42p.

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PATIENCE LAKE

  The Patience Lake potash mine is located in central Saskatchewan, ~13 km east of the city of Saskatoon (#Location: Patience Lake main shaft - 52° 5' 20"N, 106° 22' 35"W)

  Exploration and development at Patience Lake was undertaken by the Potash Company of America in the early 1950's and included 14 drill holes over an area of ~370 2, supported by seismic reflection surveys. Construction of the Patience Lake shaft began in 1954 and was completed at a depth of 1051 m in June 1958. It was the first successfully developed shaft from which potash was mined in Saskatchewan. The principal impediment to the sinking of shafts had been the water bearing units in the stratigraphic column above the host Prairie Evaporite Formation. The principal of these was the poorly consolidated sand-shale-clay-siltstone unit, the Blairmore Formation with water under pressure of 33 kg/cm2. Another ten or more such water-bearing units are found in the same section, some under pressures of >70 kg/cm2. This was overcome by pre-freezing the water bearing sequence, excavating a section of the shaft and lining with concrete.
  The Potash Company of America commenced production at Patience Lake as a room and pillar conventional mine in November 1958 at a rate of 355 000 tonnes per annum of muriate of potash (KCl) product from the Patience Lake Potash Member. However, in 1959, water began migrating through freeze holes and penetrated the concrete shaft lining, becoming so severe that production had to stop. The inflow was not reduced to manageable levels until 1965, when production finally recommenced. Conventional underground mining continued until 1987, during which time room and pillar mining serviced by ~600 km of openings was completed over an area of > 50 km2 (Goodbody, 2024).
  Another inflow of brine into the mine began in early 1986, and escalated until, by January 1987, it had proved to be unmanageable, resulting in the underground mine being abandoned and allowed to flood.
  The Patience Lake Mine is located a few kilometres from a large salt-removal structure that was later to be known as 'the Saskatoon Low' (Christiansen, 1967). The Saskatoon Low borders the western and southern boundaries of the Patience Lake mining lease and has removed much of the salt back above the Patience Lake Member that is required to form a seal that prevents inflow of water from the overlying aquifers. The presence and significance of the Saskatoon Low had not been appreciated in 1958 when the mine was opened, and no drilling or seismic surveys covered the south side of the mine until after 1976.
  The mine was reopened in 1988 as Saskatchewan’s first solution potash mine. Potash is now produced during the winter months by circulating brine through the old mine workings using a network of brine injection wells. The brine that is injected is saturated with sodium chloride (NaCl) and undersaturated in potassium chloride (KCl). As it circulates, it warms, and KCl is selectively leached from the sylvinite in the walls of the old mine openings. The KCl-rich brine is then pumped to surface through recovery wells and piped to large surface ponds where it cools under cold weather conditions. The decrease in brine temperature results in sylvite preferentially recrystallising in the ponds to form a subaqueous potash bed. The potash is subsequently harvested by mechanical dredges, and the slurry sent to the surface plant for processing. The cold KCl-depleted pond brine is then re-heated and injected back underground to repeat the solution mining process (Goodbody, 2024; Soroka and Lahonen, 2018).

  The newly privatised Potash Corporation of Saskatchewan (or PotashCorp) acquired the Potash Company of America during the early 1990s. On the 1 January, 2018, PotashCorp of Saskatchewan completed an Arrangement with Agrium Inc. to merge and create a new parent company, Nutrien, of which they were both wholly owned subsidiaries.

The Patience Lake mine extracts potash from the Patience Lake Member of the Prairie Evaporite Formation (https://miningdataonline.com/). Annual production is ~0.3 Mt of KCl.

  Estimated resources at the Patience Lake Mine are (after Mackintosh 2006, as quoted by Cocker et al., 2023):   • Reported in situ Resource - 362 Mt @ 18.00% K2O, for 65 Mt of contained K2O;
  • Historic production + Reported in situ Resource - 102 Mt of K2O;

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WYNYARD PROJECT

  The Wynyard Project is located ~175 km east of Saskatoon and some 65 km east and 40 km SE to ESE of the Lanigan and Jansen mines in central Saskatchewan respectively (#Location: 51° 44' 25"N, 104° 12' 25"W).

  During the 1950s and 1960s, there had been limited exploration for potash and magnesium in the vicinity of the Wynyard deposit. Four wells had been drilled, but only two of these penetrated the Prairie Evaporite Formation, including the Patience Lake, Belle Plaine and Esterhazy Members. The southern part of the area had recived no attention for potash. After studying regional legacy data, Karnalyte Resources Inc. was granted title over the Wynyard area in 2008 and drilled two potash exploration holes and one water source test in September, 2009.

  As elsewhere in the nested Williston/Elk Point basins of Saskatchewan, the sequence comprises a thick lower succession of principally Palaeozoic carbonate and evaporite rocks, punctuated by sandstones and shales interbeds, that extend from depths of >1900 m to the Palaeozoic/Mesozoic unconformity. These are overlain by a medial succession of bedded Mesozoic rocks, predominantly shales, siltstones and sandstones, with aquifers of brackish water. These extend from the Palaeozoic unconformity, which is at a depth of ~550 m, to the base of the overlying Cenozoic glacial tills, gravels and clays that are 125 to 175 m in thickness and contain fresh water aquifers.
  The three major Prairie Evaporite Formation potash units are present within the project area, namely the Esterhazy, Belle Plaine and Patience Lake members, whilst the White Bear Marker Beds are only poorly developed and not easily identified. However, the main contrast with the other deposits of the belt is that the potash in the Patience Lake and Belle Plaine members is predominantly present as carnallitite, although the Esterhazy Memer is composed of sylvinite. The character of these members in the Wynyard Project area is summarised as follows:
• Esterhazy Member, which varies from 3.04 to 15 m in thickness, with the upper contact ranging from a depth of 971m in the north to 1074 m in the south. As detailed above, it's potash content is present as sylvite (KCl), although carnallite (KCl•MgCl2•6H2O) is present as intercrystalline disseminations. The mineralisation generally occurs within two to three distinct high grade Sylvite zones, separated by Sylvite bearing halite. The typical sylvinitic interval comprises a mass of interlocked subhedral to euhedral sylvite crystals, ranging from reddish orange or pink to translucent. Sylvite may be surrounded by greenish-grey clay or bright red iron oxides, with minor inter-crystalline halite disseminated throughout. Local coarse, >20 to 25 mm cubic, translucent to milky white halite crystals may be present within the sylvinite groundmass. Overall, the sylvinite ranges from a dusky brownish-red, lower grade, 23.0 to 27.0% K2O with increased insolubles, to a bright, almost translucent pinkish-orange high grade, >30.0% K2O. Solution mining is planned to exploit the sylvitite of the Esterhazy Member, where the productive horizon exceeds 2 m in thickness and 20% KCl.
• Belle Plaine Member, the base of which is marked by a clay seam and a grade decrease. Its upper contact ranges from a depth of 927 m in the NE, to 1030 m in the south, whilst its thickness varies from 14.69 to 17.57 m. It can be divided into the i). Lower Belle Plaine Member, composed of interlayered halite rich beds with some carnallite and subordinate carnallite-rich beds, with thin sylvite-rich beds towards the base of the Member; and ii). a relatively homogeneous Upper Belle Plaine Member, comprising carnallite-rich beds with minor halite-rich interlayers. The carnallitite of these beds comprises crystal mass aggregates of very coarse interlocking amorphous carnallite with minor inclusions of halite and interstitial insolubles. The carnallite commonly has a dark red to bronze colour, and may locally grade to shades of very pale pink to almost colourless. Carnallite crystals often have a characteristic variegated colour zoning, plastic texture, and vitreous lustre along broken and cut core surfaces. Due to its very fragile nature and high solubility, core preservation varies considerably within the carnallitic intervals ranging from very good to poor and rubbly. Intervening barren halite beds between potash members typically comprises brownish-red, vitreous to translucent halite with minor sylvite and increased clay content. The mineable carnallitite section constitutes the Upper Belle Plaine Sub-member.
• Patience Lake Member, the stratigraphically uppermost potash bearing Member of the Prairie Evaporite Formation, in which the dominant potash mineral is also carnallite. It can be subdivided into the Lower and Upper Patience Lake Potash Sub-members, separated by a thin barren halite interbed. Within the Wynyard Project Area however, the Upper Sub-member is only found locally in the west, with just a single layer of relatively continuous Lower Patience Lake mineralisation occurring elsewhere. Carnallite constitutes ≥40% of the member, with very little sylvite, which is mainly found in the Upper Patience Lake Sub-member, where present. The top of the member is at a depth of ~910 m in the NE of the Project Area, increasing to ~1010 m in the SW. It averages 9.4 m in thickness, ranging from up to 15 m in the south, to ~3 m a few km to the west. It is characterised by its clay-rich nature, with a number of laterally extensive clay seams and a high insoluble content. The mineable carnallitite section of the Patience Lake Member is defined as the averaged >15% KCl mineralised interval below the Second Red Beds (the regionally distributed basal red shale of the Dawson Group that overlies the Prairie Evaporite Formation). NOTE: Sylvite (KCl) = 63.2% K2O; carnallite (KCl•MgCl2•6H2O) = 17.0% K2O.

  Planned solution mining consists of 2 lower caverns in the Lower and Upper Esterhazy Member respectively, and a third upper combined cavern in the Belle Plaine and Patience Lake Members. The second and third caverns are to be separated by a 28 m thick layer of halite. Individual caverns are planned to have lateral dimensions of 170 x 100 m with a maximum height of 7 m in the Esterhazy Member and 35 m in the combined Belle Plaine - Patience Lake members. The injection and recovery wells serving each cavern are to be 70 m apart. The individual caverns are to be separated by 80 m laterally. Different processes will be employed for the sylvite of the Esterhazy Member and the carnallite of the Belle Plaine and Patience Lake members.

Ore Reserves and Mineral Resources as published on the Karnalyte Resources website (viewed August, 2024):
  Patience Lake + Belle Plaine members Carnallite ore
    Proved Reserves
      - 268.6 Mt of mineralised material @ 18.7% KCl (11.8% K2O), containing 50.3 Mt of mineable KCl and 46.6 Mt of recoverable product;
    Probable Reserves
      - 425.1 Mt of mineralised material @ 18.6% KCl (11.75% K2O), containing 78.9 Mt of mineable KCl and 73.2 Mt of recoverable product;
  Esterhazy Member Sylvite ore
    Proved Reserves
      - 52.8 Mt of mineralised material @ 26.2% KCl (16.55% K2O), containing 13.8 Mt of mineable KCl and 12.9 Mt of recoverable product;
    Probable Reserves
      - 61.6 Mt of mineralised material @ 25.6% KCl (16.17% K2O), containing 15.8 Mt of mineable KCl and 14.6 Mt of recoverable magnesium products;
  These estimates total 147 Mt of recovered KCl in Ore Reserves. This is based on the products containing 97% KCl, and a plant efficiency of 90%. At the planned 2.125 Mt per annum production rate, the mine would have a 70 year life.
  However, only a part of the MgCl2 leached from the carnallitite along with the potash during solution mining is transformed into a saleable product; the remainder is considered to be waste. The amount produced depends upon the capacity of the magnesium products plant, and how much is required to meet the somewhat limited market demand. The saleable products are MgCl2 brine and hydromagnesite. For this reason a 5.8% magnesium chloride transformation is applied to all magnesium chloride mined that is available to be transformed to saleable magnesium products.
  The Probable Ore Reserve tonnage for Mg products has been taken as the Proved + Probable Ore Reserve tonnages for the canallite bearing members, namely the Patience Lake + Upper and Lower Bell Plaine members, as follows:
  Probable Magnesium Chloride Reserve - 694.6 Mt of mineralised material @ 22.1% MgCl2, containing 153.3 Mt of mineable MgCl2 and 7.9 Mt of recoverable product after the 5.8% MgCl2 factor is applied.

  The information in this Wynyard summary has been largely drawn from Rauche, H., van der Klauw, S., Piche, L. and Buckner, E., 2016 - KCl and MgCl2 Mineral Reserve and Resource Estimate for the Wynyard Carnallite Project, Subsurface Mineral Leases KL 246, KL 247 and KLSA 010, Saskatchewan, Canada; an NI 43-101 Technical Report prepared by Ercosplan Ingenieurgesellschaft Geotechnik und Bergbau mbH, North Rim Exploration Ltd. and Amec Foster Wheeler Canada Ltd, for Karnalyte Resources Inc., 293p.

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ESTERHAZY

  The Esterhazy Facility complex is centred ~15 km east of the town of Esterhazy, 90 km SE of the city of Yorkton and 220 km east of the city of Regina. It comprises three separate conventional mine and mill sites, K1, 2 and 3, and a fourth un-mined resource K4, which is located to the NE, all within southeastern Saskatchewan, Canada. The K1 mill site is located 14 km NE of;   K2 is 22 km east of;   and K3 is 6 km east of the town of Esterhazy respectively. K4 is over 30 km ENE of Esterhazy (#Location: Esterhazy K2 - 50° 39' 38"N, 101° 50' 44"W).

  Activity on the Esterhazy project began in 1955 when International Minerals and Chemicals (IMC Corporation), Canada Limited was granted a >2000 km2 lease in the Esterhazy area and commenced exploration and delineation drilling. This was followed in 1957 by the sinking of the K1 shaft, and upon its completion in 1962, the first production at a rate of 0.9 Mt per annum, expanded in 1966 to 1.5 Mtpa. The K2 facility was commenced in 1965 and completed in 1967, taking the complex capacity to 2.4 Mtpa. A major inflow was detected in 1985 some 5.6 km SE of K2, followed by installation of 22 pumps with a combined capacity of 1800 litre/minute which allowed mining to continue at both K1 and K2. Drilling and seismic surveying continued with 12 holes completed by 1989, to further delineate the resource at K1 and K2. In 1997 IMC Global and Freeport-McMoRan's potash division merged to form IMC Potash, which in 2004 was merged with the crop nutrition division of Cargill Inc., to form The Mosaic Company, which now (2024) owns and operates the Esterhazy Mine. In 2006, exploration drilling of 10 holes, including two shaft pilot holes, was completed as part of the K3 expansion project. The K3 South shaft was commenced in 2012, and sunk to potash level in 2013. The K3 North shaft was completed in 2017, and the first K3 ore from the South shaft was hauled to surface and trucked to the K1 mill. An overland conveyor from the K3 complex was completed and the first ore delivered to the K2 mill in December 2018. In May 2021, adverse brine inflow led to the premature closure of the K1 and K2 mines. The capacity of the Esterhazy Facility before this closure had been 6.0 Mtpa of muriate of potash (KCl). Ore tonnages and global grades in 2019, 2020 and 2021 were 11.9 Mt @ 23.6%, 15.0 Mt @ 24.1% and 13.3 Mt @ 23.9% K2O respectively.
  Due to the early closure of K1 and K2, production from K3 was ramped up to replace the shortfall. Production is expected to decrease from 2051, with mining anticipated to be completed in 2054. The K4 mineral resources is planned to commence mining in 2050, following, or near depletion of the K3 resource. The production plan is based on an average mining rate of 17.527 Mt of ore per annum.
  Potash at the Esterhazy Facility is extracted by conventional underground mining using continuos mining machines in a room-and-pillar layout, with a planned extraction of 27.6% of the in situ ore, with the remainder left in pillars. The average mining height is 2.6 m. The SG of the ore is 2.0804, and averages 27.1% K2O from in-mine channel sampling. Processing recovery ranges from 85 to 88%, averaging 86.1%.

  The Esterhazy Facility exploits potash-rich beds within the Middle Devonian Prairie Evaporite Formation that was deposited within the intracratonic Elk Point Basin. The potash rich beds are distributed over a stratigraphic thickness of 30 to 40 m, and at Esterhazy are at a depth of 1630 to 1750 m below the surface, similar to Belle Plaine described below. As described in the more detailed Belle Plaine description above, the Prairie Evaporite Formation is divided into a basal lower salt and an overlying unit containing three potash-bearing members and another comprising thin potash marker beds. These four potash bearing members, are from the base, the Esterhazy, White Bear and Belle Plaine Members, and the uppermost Patience Lake Member which is absent at Esterhazy. The Belle Plaine and White Bear members are too thin or too low grade to be economic at Esterhazy, and only the Esterhazy Member is mined at K1, 2 and 3.
  Mosaic (2021) described the typical sylvinite intervals within the Prairie Evaporite Formation at Esterhazy as comprising a mass of interlocked sylvite crystals that range from pink to translucent, and may be rimmed by greenish-grey clay or bright red iron insoluble material, with minor halite randomly disseminated throughout the mineralised interval. Large, translucent to cloudy, ~2.5 cm cubic halite crystals may occur within the sylvite groundmass. Overall, the sylvinite grades from a dusky brownish red, lower grade, 23% to 27% K2O, to a bright, almost translucent pinkish orange colour, with an increase in insoluble material and high grade, >30% K2O variety. Carnallite is also found locally within the Prairie Evaporite Formation as a mineral fraction of the depositional sequence. The intervening barren salt beds comprise brownish red, vitreous to translucent halite with minor sylvite and carnallite, and increased insoluble content.
  The average total thickness of the potash mineralisation in the Esterhazy area is 2.6 m, as is the production panel mining height, although the development mining height is 2.7 m.

Reserves and Resources at Esterhazy K1, 2 and 3, as at 31 December, 2022, were (The Mosaic Company, 2022 SEC Form 10-K):
  Measured Mineral Resource - 0.255 Gt @ 23.3% K2O;
  Iindicated Mineral Resource - 2.092 Gt @ 22.8% K2O;
  Measured + Indicated Mineral Resource - 2.347 Gt @ 22.9% K2O;

  Proved Ore Reserve - 110.0 Mt @ 23.3% K2O;
  Probable Ore Reserve - 433.0 Mt @ 20.9% K2O;
 Total Ore Reserve - 543.0 Mt @ 21.3% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Geological information and resource/reserve estimates were drawn from: The Mosaic Company, 2022 - Form 10-K report to the United States Securities and Exchange Commission; 387p.

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ROCANVILLE

The Rocanville potash mine is located in southeastern Saskatchewan, near the Saskatchewan-Manitoba Provincial Border, ~15 kilometers north-east of the town of Rocanville. (#Location: Rocanville #2 shaft - 50° 28' 19"N, 101° 32' 43"W).

  Exploration drilling for potash in the Rocanville area was undertaken in the 1960s, with 34 holes in all, 25 of which were in Saskatchewan and 9 in Manitoba. The Rocanville mine was constructed by Sylvite of Canada Ltd., a division of Hudson Bay Mining and Smelting Ltd. in the late 1960s, with the first potash production in 1970. The mine has operated continuously since then to the present (2024). In 1977, the then state owned Potash Corporation of Saskatchewan (PotashCorp) acquired the Rocanville mine, which it retained when privatised after 1988 following a change in Provincial government. A major expansion announced in 2007 was completed by the end of 2016, and production was ramped up through 2017 to a capacity of 6.5 Mt of finished potash product. On January 1, 2018, PotashCorp completed an Arrangement with Agrium Inc. to merge and create a new parent company, Nutrien, of which they were both wholly owned subsidiaries.

  Of the four main potash members within the Prairie Evaporite Formation of Saskatchewan, the uppermost Patience Lake Member beds are absent in the Rocanville area. The Belle Plaine and White Bear Members, whilst present, are not conventionally mineable due to grade and thickness respectively. The potash zone at Rocanville is hosted within the Esterhazy Member, near the top of the Prairie Evaporite Formation. The mineralised unit is relatively flat lying, at depths of 895 to 1120 m below the surface. The salt back cover from the ore zone to overlying units of the Dawson Bay Formation is ~30 m.
  The Esterhazy Member overlies a lower halite that is at least 5 m thick, and commences with a lower ~3 m of sylvinite, the upper >2.5 m of which constitutes the Mining Horizon. This is overlain progressively by ~0.65 m of halite; ~0.8 m of sylvinite; ~1.3 m of halite and a further ~2.15 m of sylvinite, marking the top of the Esterhazy Member. This is overlain by 5.5 m of halite separating the Esterhazy and White Bear members. The latter comprises 2.2 m of sylvinite, 0.83 m of halite and ~1 m of sylvinite, followed by a hanging wall halite that is ~11 m thick, and overlain by the Second Red Beds Member of the basal Dawson Bay Formation
  While the resources and reserves quoted below are to a thickness of 2.51 m, the continuous miners that extract ore are of various mining heights and may take a greater thickness of underlying sylvinite. The older machines cut at a thickness of 2.44 m. These were adjusted to take a thicker 2.51 m, whilst six newer mining machines cut a slightly thicker 2.59 m mining height, and two more newly acquired continuous miners cut at 2.74 m. Mining machines at Rocanville use potassium sensing technology to ensure that rooms are always cut in the best available potash ore.
  The average ore grade reported from 32 historic surface drillhole intersections, all within the Rocanville Subsurface Mineral Lease, is 22.28% K2O equivalent.
  Over the three years (2019, 2020, 2021), the average, measured potash ore grade of the mill feed at Rocanville was 22.4% % K2O equivalent. The average ore grade observed from thousands of in-mine samples collected to the end of December 2021 is 23.1% K2O equivalent. The Rocanville mine operates as a conventional, underground potash mine.

Reserves and Resources (NI 43-101 compliant), as at 31 December, 2021 were:
Rocanville at a mining height of 2.51 m, and ore density of 2.08 tonnes/km3;
  Measured Mineral Resource - 2.017 Gt;
  Indicated Mineral Resource - 1.575 Gt;
  Inferred Mineral Resource - 0.902 Gt;
 Total Mineral Resource - 4.494 Gt, with an average grade of 23.1% K2O, covering the total mine lease KL305 area of 1139.75 km2.
NOTE: Measured Resources also include remnant pillars in mined out areas, as these may be retrieved by solution mining later.
  Proved Ore Reserve - 189 Mt;
  Probable Ore Reserve - 293 Mt;
 TOTAL Ore Reserve - 483 Mt at an average grade of 23.1% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

  The information in this Rocanville summary has been largely drawn from Funk, C., Derkach, J., MacKenzie, L. and Lawlor, J.N., 2022 - Rocanville Potash Deposit (KL305), Saskatchewan, Canada; an NI 43-101 Technical Report prepared for Nutrien Limited, Saskatoon, Saskatchewan, Canada, 45p.

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BELLE PLAINE

  The Belle Plaine potash mine is located ~4 km north of the TransCanada Highway, 51 km west of Regina in south central Saskatchewan, Canada (#Location: 50° 25' 44"N, 105° 11' 58"W).

  Between 1956 and 1966, Pittsburgh Plate Glass undertook significant research into solution mining and potash recovery and published several papers on their findings. As part of this research project, a pilot solution mining plant was constructed in 1960, located at the current Belle Plaine mine site. The success of this pilot plant convinced Pittsburgh Plate Glass to develop the first commercial potash solution mining operation in the world at Belle Plaine. Drilling of the first exploration and resource definition hole in the Belle Plaine area was commenced in August 1960, followed by 14 additional holes drilled between August 1960 and June 1968. Kalium Chemicals, Ltd, a subsidiary of Pittsburgh Plate Glass, and Armour and Co. constructed the pilot plant in 1960, which was then expanded to the production plant with an annual capacity of 0.544 million tonnes of KCl product (muriate of potash). Construction of the production wells and processing plant was completed in 1964, afer which production commenced. The first rail car of potash was produced and shipped in August of that year. The capacity of the operation was progressively expanded to 1.5 Mt per annum by 1984 and to 2 Mt per year in the early 1990s. In 1989, the Belle Plaine facility was sold to the US based Vigoro Corp., which was, in turn, acquired in 1996 by IMC Global Inc. Detailed 2D seismic surveys of the mine lease were commenced in 1997, followed by a series of ever expanding 3D surveys over wider areas through to 2010. In January 2004, IMC was merged with the crop nutrition division of Cargill Inc., to form The Mosaic Company, which now (2024) owns and operates the Belle Plaine Mine. The mine and processing plant's capacity was progressively expanded to achieve a proven peak capacity of 3.9 Mt per annum in 2016.
  NOTE: The capacity refers to the tonnes of Muriate of Potash (MOP, which is KCl) that is produced.
  NOTE: As mining at Belle Plaine is by in situ underground leaching (as described below), with only KCl saturated brines being brought to the surface, Mosaic (2022) calculates an 'ore tonnage equivalence'. This is the the tonnes of ore required to be hauled to the surface from a conventional mine to produce the same tonnage of KCl, calculated from the tonnages of KCl produced, divided by the estimated global grade of the deposit. The calculated equivalent ore tonnages and global grades in 2019, 2020 and 2021 were 11.0 Mt @ 19.3%, 12.6 Mt @ 18.0% and 11.9 Mt @ 18.0% K2O respectively, which correspond to between 3.36 and 3.6 Mt of 'muriate of potash', i.e., KCl.

  The underground solution mining process employed at the Belle Plaine Facility utilises paired wells that are directionally drilled, cased, and cemented to the base of the potash beds. Solution mining techniques are utilised to target mining of the potash beds while minimising dissolution of halite. Mining practices allow for all three economic potash beds (i.e., the Patience Lake, Belle Plaine and Esterhazy members) of the Prairie Evaporite Formation to be mined. During the early stages of the mining process, the paired wells are spaced such that they can each develop a cavern that becomes hydrologically connected with the other across the interval separating them underground. This then allows for one well to become the feed or injection well and the other the return well. Hot water, or weak, undersaturated brine, is injected via the feed well into the cavern that develops between the two wells and forms a salt saturated and potash rich brine that is extracted through the return well. This fluid is pumped through pipelines from the mining area and sent to the refinery complex as raw feed for processing. The total life cycle of each cavern is ~25 years. Once the potash recovery is exhausted, each cavern is plugged and decommissioned in accordance with government regulations. The mining area capability is scheduled to support a finished tonnage projection of 3.0 Mt of MOP (KCl) per annum and will do so until drilling is completed in the year 2066 at which point there is a ramp down in production until 2084.
  In the refinery the raw feed brine from the mining area is subjected to changing temperatures and pressures that selectively precipitate the NaCl and then the KCl out of solution in different stages of the process. This is achieved through concentration in gas-fired steam heated evaporators, followed by a thickener circuit for clarification, and then to a crystalliser circuit. The latter subjects the processed brine to a vacuum that allows further boiling, creating a cooling effect on the brine. As the brine cools, the KCl is forced to precipitate from solution. The solid KCl is withdrawn from the crystalliser vessel as a slurry and pumped to the dewatering and drying area. Brine that overflows the crystalliser circuit, still contains some dissolved KCl and NaCl, and is fed to the cooling pond area for further KCl recovery. The ponds facilitate atmospheric cooling, which allows KCl to preferentially precipitate out of the brine and then settle to the bottom of the ponds to be retrieved by KCl dredges.

  As described previously, the Belle Plaine Facility exploits potash-rich beds within the Middle Devonian Prairie Evaporite Formation that was deposited within the intracratonic Elk Point Basin. The potash rich beds are distributed over a stratigraphic thickness of 30 to 40 m, and at Belle Plaine are at a depth of 1630 to 1750 m below the surface.
  The Prairie Evaporite Formation is divided into a basal lower salt and an overlying unit containing three potash-bearing members and a fourth comprising thin potash marker beds. These four members are composed of sylvite and halite with minor amounts of carnallite. In the Belle Plaine area, each of the four potash bearing members are separated by halite, and are, from the lowermost, upwards, the:
• Esterhazy Member - the lowermost main potash bed, which is underlain by halite. This member is exploited by solution mining techniques at the Belle Plaine Facility and by conventional underground techniques at the Esterhazy Facility to the east;
• White Bear Member - which forms a distinctive marker bed suite that comprises a sequence of clay seams and low-grade sylvinite and halite horizons that are not mineable due to insufficient grade and thicknesses of only 1.2 to 1.5 m;
• Belle Plaine Member - separated from the overlying Patience Lake Member by a zone of low grade sylvinite. It is subject to solution mining techniques at the Belle Plaine Facility, but is not conventionally mined there or elsewhere;
• Patience Lake Member, the uppermost member of the Prairie Evaporite Formation that has potash production potential. The interval between the top of the Patience Lake Member and the top of the Prairie Evaporite Formation is occupied by a 0 to 13.5 m thick unit of halite with clay seams, known as the 'Salt Back'. The sylvite-rich horizons within the Patience Lake Member are mined by conventional underground mining techniques along a trend from Vanscoy to Lanigan to the north, in the Saskatoon area, and by solution mining techniques at Belle Plaine in the regina area.
  There are also numerous, thin, barren insoluble clay-rich seams throughout the sequence.
  The potash deposit at Belle Plaine is uniform and laterally continuous. Solution mining methods can more easily accommodate any local variations in geological condition due to the non-selective concentrate mining process.
  At the Belle Plaine Facility, the following terminology is applied to the beds, summarising the distribution of grades that are available for solution mining:
• The Lower Mining Zone, which is ~6 m thick and comprises beds 13, 12 and 11 of the Esterhazy Member;
• The Interzonal Salt - a thick bed of salt located between the Lower and Upper Mining Zones;
• The Marker Bed - which is a small, very rich potash bed located midway through the Interzonal Salt, the White Bear marker;
• The Upper Mining Zone - which is ~27.5 m thick and includes beds 38 to 31 of the Patience Lake Member and beds 23 to 21 of the Belle Plaine Member. • The Salt Stringer - a thin, ~3 m thick, bed of salt located between Beds 31 and 23 in the Upper Mining Zone;

Ore Reserves and Mineral Resources at Belle Plaine, as at 31 December, 2022, were (The Mosaic Company, 2022 Form 10-K):
  Inferred Mineral Resource - 4.647 Gt (equivalent) @ 19% K2O; (No Measured or Indicated Resources calculated)
  Proved Ore Reserve - 272 Mt (equivalent) @ 19.3% K2O;
  Probable Ore Reserve - 388.0 Mt (equivalent) @ 19.3% K2O;
 TOTAL Ore Reserve - 660.0 (equivalent) Mt @ 19.3% K2O.
NOTE: Mineral Resources are exclusive of Ore Reserves.

Geological information and resource/reserve estimates were drawn from: The Mosaic Company. 2022 - Form 10-K report to the United States Securities and Exchange Commission; 387p.

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BETHUNE, previously LEGACY, and FINDLATER

  The Bethune Mine is located ~27 km NNW of the Belle Plaine potash mine, ~50 km north of Moose Jaw, and ~60 km NW of Regina in southern Saskatchewan (#Location: 50° 38' 53"N, 105° 22' 40"W).

  The area of the 393 km2 Subsurface Mineral Lease KLSA 009, within which the Bethune Mine is located, was explored during the late 1950s and 1960s by both Imperial Oil and Lumsden Potash Development Company, Ltd. Both drilled and then completed solution mining tests, which determined that economic thicknesses of the Patience Lake, Belle Plaine and Esterhazy members of the upper Prairie Evaporite Formation are present, and are amenable to solution mining. In the east of the current lease area, Lumsden drilled two holes into the Prairie Evaporite Formation during 1967 at their Bethune test site. A pilot plant was installed and tests were conducted, aimed at primary cavern formation within the evaporites. This involved the creation of fluid communication between the two drill holes by fluid injection and hydraulic fracturing. The results were apparently encouraging, although the pilot plant and test program were subsequently abandoned.
  Imperial Oil conducted similar tests at the Findlater site, some 18 km to the NW of Bethune. They commenced work in 1960, which included initial reflection seismic surveys. They also drilled paired holes into the evaporites and circulated fluids between the two through a cavity system at variable rates and temperatures. However, this project was also abandoned in 1966, which, it is rumoured, was because of low concentrations of KCl in the return fluid, related to problems with the solution technology i.e., the failure of the horizontal fracturing techniques to adequately connect the two pilot holes.
  In November 2005, Subsurface Mineral Permit KP 289 was granted to Invictus Minerals Corporation. In May 2006, ISX Resources Inc. entered into an option agreement with Invictus to explore within, and to acquire the permit from Invictus. During 2007 a scoping study, based on legacy data, was conducted to ascertain what potential there was to outline and solution mine a significant resource. On the basis of this study, it was decided to proceed on what was known as the Legacy Project. During 2007, a 3D seismic survey was undertaken over the Buffalo Pound area surrounding the Findlater pilot test area in the northwest of the Permit. In early 2008, ISX Resources changed its name to Potash One Inc. Their 2008-09 program was designed to evaluate the potash potential of ground away from the historical Imperial and Lumsden Potash pilot sites, and determine whether the deposit encountered could be deeper, thicker and hotter. As the solubility of sylvite increases with temperature, and temperature increases with depth, a deeper resource is favoured. The potash beds of the Prairie Evaporite Formation both thicken and dip gently to the south. Two- and three- dimensional seismic surveys were completed as well as a six-hole exploration drilling program to outline the thickness, continuity and grade of the potash beds. As a result of this work, the resource to be mined is now centred on those six holes that defined an ~50 km2 area some 10 km SW of the Lumsden Bethune test area, and ~12 km SSE of the Imperial Oil Findlater test area, where a smaller resource earmarked for later development is centred.
  Positive pre-feasibility and feasibility studies were completed in 2009 and 2010 respectively. In November 2010, the German K+S Group acquired Potash One in a friendly takeover to form K+S Potash Canada (KSPC) when finalised in March 2011, and to develop the Legacy Potash Mine. Construction of key infrastructure commenced in 2012, including test wells and cavern development, as well as further production drilling in the winter of 2012-13. The mine officially opened in May of 2017, and was renamed the Bethune Mine. The first marketable potash was shipped in June 2017.
  The solution mining at Bethune is undertaken in two phases. The primary phase involves the drilling of a pair of cased wells 80 m apart to the base of the potash-bearing evaporites, and fresh water being injected under pressure into one and brine being pumped to the surface from the second. This dissolves the potash bearing evaporites and forms two circular, tabular, interconnected caverns ~80 m apart, and ~1500 m below the surface. The secondary phase involves pumping an NaCl-saturated brine into the injection well to selectively dissolve the KCl from the walls and roof of the caverns, which then exits via the recovery well to the surface, where it is piped to the processing plant for concentration and crystallisation. Where more than one potash member is being mined, the lowest is extracted first before the two well casings are withdrawn to the next above, the intervening waste layer is plugged and the process repeated. multiple caverns are worked at the same time.
  As at the Belle Plaine Mine, immediately to the south, all three of the main potash members of the Prairie Evaporite Formation are present and mined. See the Belle Plaine description above and the other mine descriptions and regional geological sections for details of the host sequence.
  The following sequence was intersected in drilling for Cavern 1 at Bethune, from the base upwards:
• Footwall halite, that is >10 m thick, overlain by ~5 m of sylvite bearing halite;
• Esterhazy Potash Member, comprising a thin basal bed of sylvite; followed by 2.1 m of sylvite bearing halite; 1.5 m of low grade sylvinite; 2.1 m of argyllitic sylvinite; and 4.5 m of sylvinite. The top of the member is marked by a locally variable, but regionally persistent clay zone that typically overlies the uppermost sylvinite bed of the member. The member totals 10.3 m @ 21.6% KCl (13.65 % K2O). In comparison with the other potash-bearing members in the Mineral Lease area, the Esterhazy Member contains the least quantities of clay, averaging 2% insolubles, and is characteristically coarse grained. Cloudy, iron oxide rimmed, reddish pink to dark grey sylvite crystals that average 5 to 26 mm in diameter are intergrown with translucent, colourless to pale orange to clay-included halite crystals averaging 7 to 30 mm in diameter. Sylvite and halite crystals are locally up to 75 mm and 100 mm in diameter respectively. Halite also occurs as massive aggregates throughout the Esterhazy Member.
• Waste rock, that includes the White Bear Marker Beds, commencing with low grade sylvinite; sylvite bearing halite; the thin sylvinite Interbed 2; argyllic halite; sylvite bearing halite; more argyllic halite; argillic sylvinite; argyllic halite; and a sylvite-bearing halite bed. This interval, which separates the Esterhazy and Belle Plaine members, is ~18 m thick in the Cavern 1 drill hole. The White Bear Marker Beds are represented by thin interbedded clay, halite, and sylvinite units that occur within the barren halite above the Esterhazy Member. The beds are composed of a lower suite of sylvite-bearing halite, overlain by Interbed 2 sylvinite and argyllic halite, separated by sylvite bearing halite from an upper thin argyllic sylvinite sandwiched between argyllic halite beds. The higher grade sylvinite within the White Bear Marker Beds is too thin to be considered as a potential resource at Bethune.
• Belle Plaine Potash Member, comprising two alternations of low and high grade sylvanite beds, the first with 3 and 2.5 m , the second with <1 m and 2.8 m of low and high grade respectively. The member totals 8.5 m @ 29.5% KCl (18.6% K2O). The Belle Plaine Member is typically 7.5 m thick throughout the Mining Lease, It's upper contact ranges from 1520 to 1592 m below the surface. It has a lower clay content, averaging 7% insolubles, and is characterised by slightly coarser sylvite crystals compared to the Patience Lake Member, averaging 3 to 13 mm in diameter, to locally as much as 45 mm. Sylvite is intergrown with translucent, pale orange to colourless, 6 to 22 mm halite crystals that are locally as much as 35 mm in diameter. Halite locally includes fine-grained clays, imparting a cloudy appearance.
• Interbed 1, a sylvite bearing halite that is ~2.5 m thick in the South 1 drill hole, but may be as thick as 12 m, although it averaged 4.97 m. It has sufficient KCl grade tp be included in the Mineral Resource inventory in sections of the mine.
• Patience Lake Potash Member, commences with a lower ~6 m mixed interval that commences with interbedded thin beds of sylvinite, sylvite-bearing halite, argillitic sylvite and low grade sylvinite, followed by two thicker beds, each ~2 m thick, the first of sylvite-bearing halite, the second of argillitic sylvinite, capped by another thin sylvite-bearing halite. This mixed interval is overlain by ~5 m of high grade sylvinite, with thin clay seams, followed by ~1.5 m of argillitic sylvinite, and then another 3.5 m of high grade sylvinite. The latter sylvinite is overlain by a thin sylvite-bearing halite bed, then another metre of argillitic sylvinite, capped by ~2 m of high grade sylvinite, with a thin interval occupied by a clay seam and low grade sylvinte towards its centre. The Patience Lake Member within this drill hole comprise an intersection of 18.8 m @ 31% KCl (19.6% K2O).
  Within the Mineral Lease, the Patience Lake Member has an average thickness of 15 m. It's top contact ranges from 1500 to 1567 m below surface. It is the most clay-rich of the potash-bearing members of Mineral Lease area, with an average insoluble content of 11%. These clays typically occur as discrete seams that are <3 cm thick and as local clots and blebs. Sylvite crystals average 3 to 11 mm in diameter locally to as much as 44 mm. As in all of the other potash-bearing members of the Mineral Lease, the sylvite crystals are pale reddish pink to dark grey and are typically rimmed by dark red iron oxides. The sylvite is intergrown with translucent, colourless to pale orange to locally clay-included, 6 to 15 mm halite crystals that locally may be up to 100 mm in diameter. The Patience Lake Member can be split into Upper and Lower mineralised sequences within the Mineral Lease. However, as the cavern design is planned to extract potash from the entire mineralised zone, with no consideration of internal clay seam stratigraphy or poorly mineralised intervals, such subdivision is deemed un-necessary.
• Salt Back, which is at least 11 m thick, and commences with ~1.6 m of sylvite-bearing halite, overlain by interbedded low grade sylvinite, argillitic halite, halite and sylvite-bearing halite, with some thin high grade sylvinite bands in the lower half of the intersection.
• Second Red Beds, the base of which defines the top of the Prairie Evaporite Formation.

Mineral Resources are based on drill hole spacing and continuity as defined in 3D seismic surveys. Hardy, Halabura and Shewfelt (2010) defined Measured Resources and Proved Ore Reserves as being within a radius of 800 m around an assayed cored drill hole. Indicated Mineral Resources and Probable Ore Reserves are based on a drill spacing of 1.6 km. However, where adjacent cored drill holes are within 3.22 km and have 3D seismic coverage between them, the maximum radius of influence has been extended to 2 km. Inferred Resources are between 2 and 8.05 km radius of a cored drill hole, with or without supporting 2D seismic surveys.
  Hardy, Halabura and Shewfelt (2010) reported the following distribution of resources within the individual potash members:
  Esterhazy Member
    Proved and Probable Reserves - 7.93 to 8.22 m thickness @ 28.35 to 31.96% KCl;
      in situ tonnage - 37.52 Mt of KCl;
      recoverable tonnage - 25.87 Mt of KCl.
  Belle Plaine Member
    Proved and Probable Reserves - 7.98 to 8.45 m thickness @ 25.44 to 27.34% KCl;
      in situ tonnage - 40.66 Mt of KCl;
      recoverable tonnage - 28.08 Mt of KCl.
  Interbed 1
    Proved and Probable Reserves - 3.23 to 4.62 m thickness @ 4.25 to 4.54% KCl;
      in situ tonnage - 4.28 Mt of KCl;
      recoverable tonnage - 2.95 Mt of KCl.
  Patience Lake Member
    Proved and Probable Reserves - 17.06 to 17.33 m thickness @ 29.42 to 29.98% KCl;
      in situ tonnage - 114.28 Mt of KCl;
      recoverable tonnage - 78.88 Mt of KCl.
NOTE: recoverable tonnage includes allowance for losses of 5% and 9% due to unidentified geologic factors in Proved and Probable Ore Reserves respectively; 80% cavern recovery; and 6% combined plant, transport, and spill losses.
  Total Proved + Probable Ore Reserve - 196.74 Mt of KCl for 135.78 Mt of recoverable KCL.

K+S Potash Canada (2012) quote the following Ore Reserves and Mineral Resources, using the same criteria:
  Within the main Bethune (Legacy mine) Resource:
    Recoverable Measured Resource = Proved + Probable Ore Reserve: 160 Mt of KCl @ 29% KCl (18% K2O);
  Within Mining Lease KLSA 009, but external to the main Bethune (Legacy) mine resource, mainly within the Findlater area:
    Recoverable Indicated Resource: 88 Mt of KCl @ 27% KCl (17% K2O)
    Recoverable Inferred Resource: 894 Mt of KCl @ 27% KCl (17% K2O)
  NOTE: The Measured Resource was considered sufficient for 56 years of production at 2.86 Mt of KCl per annum.

  The information in this Bethune/Legacy summary has been largely drawn from Hardy, M.P., Halabura, S.P., Shewfelt, D. and Hambley, D.F., 2010 - Potash Reserve Assessment for Subsurface Mineral Permit KP 289, Saskatchewan; an NI 43-101 Technical Report prepared by Agapito Associates Inc. and North Rim, for Potash One Inc., 193p. and
Hopf. H., Galenzoski, J. and Spachtholz, F.X., 2012 - The Current State of the K+S Legacy Project; Saskatchewan Geological Survey – 43rd Annual Open House; 35p..

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MILESTONE PROJECT

  The Milestone Mine and Project is located ~35 km SE of Regina in southeastern Saskatchewan, Canada (#Location: 50° 11' 23"N; 104° 17' 54"W).

  The area occupied by the Milestone Mineral Lease KLSA 008 was drilled for petroleumin the 1950s, although most of the six holes involved did not reach the Prairie Evaporite Formation. One of these did intersect the Prairie Evaporite Formation, which gamma logs indicated was 27 m thick, although the lithologic logs based on chip samples, indicated no trace of sylvite. This was taken to indicate the well was west of the 'salt edge' i.e., the limit of potash mineralisation. However, on the basis of subsequent 2D and 3D seismic surveys between 1986 and 2000, it became evident this was not the case. Between 2008 and 2010, Western Potash Corp. conducted 2D and 3D seismic surveys in their earlier permits that are now the southern part of KLSA 008. These gave sufficient encouragement to drill nine cored holes which intersected the Prairie Evaporite Formation. A further two wells were drilled and cored in January and February 2011. The current reserves and resources to be mined at Milestone are based on 10 of these drill holes, which are distributed over a north-south oriented area of 16 x 5 km. Construction of Phase I of the Milestone Solution Mine and concentrator began in June 2019, and was completed with dry commissioning in November 2023. Phase I is designed to produce 0.146 Mt of potash per annum. Phases II to IV are planned to ramp up to 3 Mt of potash per annum.

The regional setting of the Milestone resource is as for the other mines and projects in the area - see the Belle Plaine and Bethune descriptions above.
  Within the KLSA 008 Lease area, as in the other deposits in the Regina area, the Prairie Evaporite Formation includes the Esterhazy, Belle Plaine and Patience Lake Members. The distinctive White Bear Marker Beds, a unit of thin interbedded clay, halite and sylvinite beds is also present between the Belle Plaine and Esterhazy Members but is of insufficient thickness (1 to 3 m) and grade to be of economic interest. The depth to the top of the Prairie Evaporite Formation within the KLSA 008 Lease area ranges from 1650 m in the NW, to 1750 m along its southern boundary. The cumulative thickness of potash beds in the Patience Lake, Belle Plaine and Esterhazy members, excluding interbeds, ranges from some 15.8 m to 25.1 m. The individual members are as follows:
• The Esterhazy Member, the stratigraphic lowest of the three, overlies the footwall Lower Salt and varies from ~3 m in the SW to ~6 m to the NE, with irregularly distributed thin and thick zones. It averages 5.68 m in thickness, with 20.96% K2O, 4.00% carnallite and 3.96% insolubles.
• The Belle Plaine Member, in contrast, thickens from ~3.25 m in the north, to >5 m in the south. It averages 4.40 m in thickness, with 18.53% K2O, 0.56% carnallite, and 4.32% insolubles
• The Uppermost Patience Lake Member thickens from ~6 m in the NW to >12 m in the east. It averages 10.55 m in thickness with 17.97% K2O, 0.64% carnallite and 10.92% insolubles;
  A number of generally circular zones of marked thinning are interpreted to be 'geologic anomalies' (as explained earlier in this record) that have resulted from evaporite dissolution and slumping of overlying beds into the void thus formed.
  The potash beds of the three economically mineable members are composed of sylvite and halite with minor carnallite. The carnallite grades in the Patience Lake and Belle Plaine Members are sufficiently low as to not interfere with mining operations for sylvite. Conversely, the carnallite grades in the Esterhazy Member of four of the ten wells drilled by Western Potash are >6%. Carnallitic ores can be handled by the evaporator/crystalliser processing circuits used at solution mines, although the KCl losses during the magnesium purge reduces the KCl recovery. However, if brines from the Esterhazy Member can be blended with those from the Patience Lake and/or Belle Plaine Members, the resulting carnallite grade may be acceptable.

  Hambley et al. (2015) describe the typical sylvinite beds/interval within the Prairie Evaporite Formation at Milestone as consisting of a mass of interlocked sylvite crystals that range from pink to translucent, and may be rimmed by greenish-grey clay or bright-red iron insolubles, with minor halite randomly disseminated throughout the interval. Local large, >20 to 25 mm, cubic, translucent to cloudy halite crystals may be present within the sylvite groundmass. Overall, the sylvinite ranges from a dusky brownish-red colour, which is of lower grade, 23 to 27% K2O grade with an increase in insolubles, to a bright, almost translucent pinkish-orange colour containing high grade, ≥30% K2O. Intervening barren beds typically comprise brownish-red, vitreous to translucent halite with minor sylvite and increased insolubles content.

  The solution mining process planned for the Milestone mine varies from that used in other solution operations in Saskatchewan. It involves:
• the drilling of vertical, cased, injection and recovery wells to intersect at the base of the target potash bed. The injection well is then wedged and drilled to extend horizontally for a distance of 800 m along the base of the potash bed. An injection 'tubular casing' is inserted into the injection well, extending to near the outer end of that well.
• An NaCl-saturated, KCl deficient brine at 100°C is injected under pressure to the farthest end of the horizontal injection well. This selectively leaches KCl from the potash bed surrounding the end of the injection well, and returns to the recovery well along the gap/annulus between the injection casing and the evaporitic wall rock. With time this annulus is enlarged through dissolution of KCl in the potash bed to form a horizontal cavern. The brine is heated to 100° as KCl solubility is temperature sensitive, in contrast to NaCl. Vertical growth of the cavern is limited by the less soluble halite beds that limit the potash members above and below.
• When the width of the cavern is judged to have reached 100 m, the injection tubular casing is retracted some distance and dissolution is restarted. This process if repeated until the whole 800 m has been mined. Three such caverns are planned for simultaneous production during the Pilot Study project, each with a hot solvent injection flow rate of 100 m3/hour. Each cavern is estimated to be exhausted in just over 6 years.
  Mining occurs in two phases. The initial phase, involves establishing the shape of the embryonic cavern which is developed over a 3-month solvent injection period where the return weak brine, which does not have economical concentrations of KCl, is discarded. This development period comprises a 1-month ramp-up to a stable 100 m3/hour injection flow rate, which is then maintained over the subsequent 2 months. The weak brine is directed to the purge pond before being injected into the disposal well for injection into the Deadwood Formation, ~2050 m below surface.
• During the second, or production phase, the KCl rich brine from the return well at near 100°C well is pumped to the processing plant where it is cooled to 12°C by barometric cooling crystallisers, and KCl (Muriate of Potash - MOP) is preferentially precipitated. KCl solubility decreases with falling temperature whereas that of NaCl remains almost constant. The remaining NaCl saturated brine, which has been depleted of KCl, is then reheated to 100°C and re-injected into the cavern.
• A purge stream in the crystallisation circuit extract MgCl2 in the brine from the carnallite in the mining horizon. The purge stream is pumped into the disposal well via a purge pond. The KCl saturated crystalliser slurry is centrifuged and dried to produce the final MOP product.
  NOTE: Whilst this method of horizontal drilling into evaporite beds and solution mining has not been previously utilised in Saskatchewan, it has been successfully employed at mines elsewhere in the world to mine potash, nahcolite (NaHCO3) and tronah since before 2000.

Mineral Resources as published on the Karnalyte Resources website (viewed August, 2024):
  Patience Lake Member
    Measured Resource - covering an area of 4.32 km2, and thickness of 6.57 m
      59.5 Mt of mineralised material @ 17.7% K2O (28.0% KCl), 0.56% carnallite, 10.07% insolubles;
      containing 10.5 Mt of K2O = 16.7 Mt of KCl;
    Indicated Resource - covering an area of 11.38 km2, and thickness of 6.32 m
      151.0 Mt of mineralised material @ 17.7% K2O (28.0% KCl), 0.55% carnallite, 9.94% insolubles;
      containing 26.7 Mt of K2O = 42.3 Mt of KCl;
    Inferred Resource - covering an area of 219.02 km2, and thickness of 9.38 m
      4.316 Gt of mineralised material @ 18.1% K2O (28.6% KCl), 0.62% carnallite, 10.72% insolubles;
      containing 782 Mt of K2O = 1236 Mt of KCl;
  Halite Interbed
    Measured Resource - covering an area of 4.92 km2, and thickness of 8.11 m
      86.6 Mt of mineralised material @ 2.8% K2O (4.4% KCl), 0.49% carnallite, 6.82% insolubles;
      containing 2.4 Mt of K2O = 3.8 Mt of KCl;
    Indicated Resource - covering an area of 11.38 km2, and thickness of 7.65 m
      188.9 Mt of mineralised material @ 2.9% K2O (4.5% KCl), 0.49% carnallite, 6.81% insolubles;
      containing 5.4 Mt of K2O = 8.5 Mt of KCl;
    Inferred Resource - covering an area of 219.02 km2, and thickness of 3.95 m
      1.879 Gt of mineralised material @ 3.0% K2O (4.7% KCl), 0.59% carnallite, 6.89% insolubles;
      containing 55 Mt of K2O = 88 Mt of KCl;
  Belle Plaine Member
    Measured Resource - covering an area of 2.94 km2, and thickness of 3.33 m
      20.8 Mt of mineralised material @ 17.1% K2O (27.1% KCl), 0.67% carnallite, 6.81% insolubles;
      containing 3.6 Mt of K2O = 5.6 Mt of KCl;
    Indicated Resource - covering an area of 7.23 km2, and thickness of 3.43 m
      52.6 Mt of mineralised material @ 16.9% K2O, 26.8% KCl, 0.66% carnallite, 6.51% insolubles;
      containing 8.9 Mt of K2O = 14.1 Mt of KCl;
    Inferred Resource - covering an area of 217.3 km2, and thickness of 4.39 m
      2.021 Gt of mineralised material @ 19.0% K2O (30.1% KCl), 0.58% carnallite, 4.41% insolubles;
      containing 385 Mt of K2O = 608 Mt of KCl;
  Esterhazy Member
    Measured Resource - covering an area of 4.92 km2, and thickness of 6.26 m
      63.7 Mt of mineralised material @ 21.9% K2O (34.6% KCl), 5.10% carnallite, 4.77% insolubles;
      containing 13.9 Mt of K2O = 22.0 Mt of KCl;
    Indicated Resource - covering an area of 11.38 km2, and thickness of 6.24 m
      147.0 Mt of mineralised material @ 21.3% K2O (33.6% KCl), 5.00% carnallite, 4.68% insolubles;
      containing 31.3 Mt of K2O = 49.4 Mt of KCl;
    Inferred Resource - covering an area of 219.02 km2, and thickness of 5.49 m
      2491 Mt of mineralised material @ 21.2% K2O (33.5% KCl), 4.45% carnallite, 3.53% insolubles;
      containing 528 Mt of K2O = 834 Mt of KCl;
NOTE: The resources above are based on 10 cored drill holes through the upper Prairie Evaporite Formation. The Resource types are base on radii of influence around these drill holes, which are 0.8 km for Measured, 1.6 km, and where seismic cover is available 2.5 km for Indicated, and up to 8 km outside of the latter for Inferred categories. A cutoff grade of 15.8% KCl (10% K2)O was used to define the top and bottom of the target member in a given well.

  The information in this Milestone summary has been largely drawn from Hambley, D.F. and Brebner, D., 2015 - NI 43-101 Technical Report Summarizing the Scoping Study for a Pilot-Scale Selective Solution Mining Operation on the Milestone Project (Subsurface Mineral Lease KLSA 008), Saskatchewan; an NI 43-101 Technical Report prepared by Agapito Associates Inc., for Western Potash Corp., 149p.

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ALBANY PROJECT

  The Albany Project is located ~50 km southeast of Regina, near the Town of Francis and the Village of Sedley, in Saskatchewan. The 279.6 km2 Potash Lease KL 262, within which the resource is located, is immediately to the east of the Milestone Mineral Lease KLSA 008 (#Location: 50° 15' 2"N, 103° 54' 8"W).

  The Potash Lease KL 262 area corresponds to one of 26 permits acquired by North Atlantic Potash in 2008. In 2011, North Atlantic, then a subsidiary of the Russian JSC Acron Group, formed the CanPacific Potash joint venture with Rio Tinto Potash Management Inc, to explore 9 of these permits, including the area now occupied by KL 262. This lease has been explored by Rio Tinto Potash Management Inc. since October 2011. Rio Tinto holds 32% of the CanPacific Potash joint venture. Work undertaken under Rio Tinto management included a 300 km2 3D seismic survey and an additional two 2D lines. The latter confirm the full thickness of the Prairie Evaporite Formation persists up to the southern boundary of the Potash Lease. Thirteen wells have tested the Prairie Evaporite Formation at ~6 km centres in the northern half of the lease. Of these, eleven intersected the full sequence of the potash beds, one cut a dissolution collapse zone (geologic anomaly), whilst the remaining hole intercepted a zone of potash leaching. Seismic data indicates the 'geologic anomaly' encountered in drilling is the only one within the potash resource. It is circular, with a diameter of ~1.3 kilometres, representing a very minor proportion of the total resource. Seismic data also indicates the evaporite formation dips at ~0.6°, with local variations.

  The Albany Project resource is located near the southwestern margin of the Elk Point Basin, hosted within the Devonian Prairie Evaporite Formation. As at the other deposits of the basin, this formation contains an areally extensive set of mineralised potash beds. The most significant of these are the three major potash units in the upper half of the Prairie Evaporite Formation, which are, from lower to upper, the Esterhazy, Belle Plaine and Patience Lake Members. The Esterhazy and Belle Plaine members are separated by the ~19 m thick halite interbed that sandwiches the suite of interbedded clay, halite and sylvinite beds of the White Bear Marker. The Belle Plaine and Patience Lake members are separated by a single halite bed that is ~2 m thick. These units are described in detail above and in the other deposit descriptions (see the neighbouring Belle Plaine, Milestone and Bethune deposits above). At the Albany Project, these potash members are composed of halite and sylvite with minor carnallite. The latter, which is regarded as deleterious, was only observed within the Esterhazy Member, in four of the wells drilled, where it is responsible for levels of around 1.5% MgO, where present. These potash members also contain around 7 to 8% insolubles, occurring as clay bands that act as markers throughout the basin. Within the Albany resource, the three potash members are found at a depth of around 1750 m, and have formational temperatures of ~62°C. The salt back, i.e., the halite beds above the potash members, is relatively thick ranging from 7 to 26 , averaging ~10m.
  The CanPacific Potash joint venture partners propose the deposit should be exploited by solution mining, extracting all three potash members in two lifts. This is to be undertaken by developing a sequence of caverns, each serviced by an injection and a return well, which circulate hot, NaCl saturated brine to preferentially dissolve KCl from the evaporite salt beds, and pump the resultant potash rich brine to the surface for processing (see the Bethune and Belle Plaine description above for details of this process). The first lift is to target the lowest potash unit, the Esterhazy Member, which has an average thickness in the wells of 5.6 m. When the potash of this unit is exhausted, the casings of the injection and return wells are retracted to above the ~19 m thick halite dominated interbed separating the Esterhazy and Belle Plaine Members, and the well section through this unit plugged. A new cavern would then be generated to mine the Belle Plaine and Patience Lake Potash Members, which have an average thickness of ~18 m, whilst minimising dissolution of the thinner halite interbed separating the two.
  It is common for deposits of this style to include areas where the potash minerals have been leached out and replaced by halite, as encountered in drilling at Albany. These areas are not evident in seismic, nor is drilling at sufficient density to map them out. To compensate, a factor has been allowed for in the resource estimation to account for the possible presence of such zones.
  Inferred Resources are calculated from the eleven, 6 km spaced drill holes intersecting potash beds of the resources, with extrapolation extending no more than three kilometres from each well, supported by 3D seismic data. The cut-off includes a minimum thickness of 2 m and 15% K2O. In addition, the sections of the Esterhazy Member where the MgCl2 ratio exceeds the expected pant design after blending are omitted from the resource. The Inferred Resource is based on a cavern layout, with factors applied for these likely variables. These include: i). an 85% recovery of brine from each cavern allowing for losses within the cavern on closure. ii). a 92% recovery factor allowing for areas of KCl leaching within the potash bed; and iii). a 95.7% recovery factor to allow for losses due to dip in the floor of the caverns, and other losses. As the brine from the upper low grade interbed between the Belle Plaine and Patience Lake members is likely to be discarded during mining, the tonnages associated with this interbed unit have been removed.

Mineral Resources as published on the North Atlantic Potash website (viewed August, 2024) are: Inferred Mineral Resources
  Patience Lake + Belle Plaine members
    1139 Mt of mineralised material @ 19.40% K2O (30.72% KC), 0.07% MgO, 8.44% Insolubles, for 262 Mt of recovered KCl;
  Esterhazy Member
    293 Mt of mineralised material @ 19.25% K2O (30.49% KCl), 0.21% MgO, 3.59% Insolubles, for 67 Mt of recovered KCl;
  TOTAL Mineral Resource
    1432 Mt of mineralised material @ 19.37% K2O (30.67% KCl), 0.10% MgO, 7.45% Insolubles, for 329 Mt of recovered KCl.

  The information in this Albany summary has been largely drawn from the North Atlantic Potash and CanPacific Potash websites as viewed in August, 2024

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BROADVIEW PROJECT

  The Broadview Potash resources is located 12 km south of the Town of Grenfell, 120 km east of Regina and 55 km east of the Albany Project in southeastern Saskatchewan. The resource lies within the 281 km2 Mineral Lease KL 280 held by Canada Golden Fortune Potash Corporation who plan to develop a new one million tonnes per annum greenfield potash solution mine. Canada Golden Fortune Potash is a private company who does not submit NI 43-101 or public reports, so little information has been encountered on the geology. Broadview would appear to have a similar geology and mineralisation style to the Albany Resource described above.
  An exploration program was commenced within the lease area in 2015. This involved eight vertical wells that all intersected the mineralised potash members at a nominal 3 to 5 km spacing. Each was cored from the lower Dawson Bay Formation to below the Esterhazy Member of the Prairie Evaporite Formation. The core was assayed, whilst each well was logged with geophysical wireline tools. In addition, 127.5 km of 2D and 117.1 km2 of 3D seismic surveys were completed in the same year. Only the Patience Lake and the Esterhazy Members are regarded as economic (Source: Environmental Impact Statement, by SNC-Lavalin, October 2018, prepared for Canada Golden Fortune Potash Corp.).
  Mineral Resources, as published in the same Environmental Impact Statement, are as follows:
  Esterhazy Member
    Indicated Resource - 44 Mt @ 17% K2O, over a thickness of 5 m;
    Inferred Resource - 93 Mt @ 17% K2O, over a thickness of 5 m;
  Patience Lake Member
    Indicated Resource - 31 Mt @ 17% K2O, over a thickness of 5 m;
    Inferred Resource - 56 Mt @ 17% K2O, over a thickness of 5 m;
  TOTAL Mineral Resource
    Indicated Resource - 75 Mt @ 17% K2O, over a thickness of 5 m;
    Inferred Resource - 93 Mt @ 17% K2O, over a thickness of 5 m.
  The Mineral Resource is at a depth of ~1650 m below surface.
  Solution Mining - extraction is planned to be by solution mining, whereby for each set of mining caverns, two vertical, cased wells are drilled to near the level of the potash bed. Both are then wedged to curve to horizontal and intersect at the base of the potash bed to be mined - the curvature between the vertical and horizontal segments has a minimum radius of 200 m. One of the wells only, the injection well, is then extended horizontally for 750 m along the lower contact of the potash bed and cased to the end. Mining will take place on 7 parallel caverns at the same time. To facilitate this, another six paired wells are drilled from the same collar at surface and positioned so that there are 7 parallel horizontal injection wells along the lower contact of the potash bed to be mined. Each pair is ~109 m apart, designed to produce a final cavern that is 95 m wide, leaving a 14 pillar between caverns - thus mining a 760 x 750 m area of the potash bed.
  Mining i planned to proceed in four phases:
  i). Non-selective cavern development - fresh water at ~25°C is pumped to the far end of each horizontal injection well and returns via the annulus between the well wall and casing to the return/production well and is pumped to the surface in that well. This creates an initial cavern, removing both halite and sylvite, and any canallite. This stage takes ~20 days.
  ii). Selective solution mining - where near NaCl-saturated brine at near 100°C is pumped to the far end of each horizontal injection well to preferentially dissolve KCl. The KCl rich brine thus generated is returned via the cavern surrounding the injection well casing and pumped to the surface via the return/production well for cooling and KCl dissolution. When it is estimated the roof span of the cavern at the far end injection point has reached 95 m width, the injection well is plugged at that far end, and perforated closer to the return well to generate a new injection point. This is repeated progressively until the whole cavern is 95 m wide. The cross sectional shape of the mature cavern at this stage is estimated to be triangular, with the apex at the injection well level, expanding upward to the roof which corresponds to the 'insoluble' halite band capping the potash bed. An apex up triangular pillar separates adjacent caverns. This stage is estimated to take ~2 years.
  iii). Mining enhancement stage - which essentially is to reclaim the inter-cavern pillar. This involves drilling a new well laterally from the bottom of the vertical injection well, to then curve and follow the base of the potash bed along the central axis of the pillar, and repeat the same extraction steps as for the selective solution mining stage. The total length of this intervening well is ~750 m, with of the horizontal section parallel to the neighbouring wells being ~650 m. This stage is estimated to take another ~2 years
  iv). Batch Mining - when continuous selective mining cannot sustain an acceptable brine grade, i.e., most of the KCl has been removed, the cavern is placed on standby for an extended period. This allows for potash to be leached from surrounding rocks, and gradually build up, until it reaches an acceptable concentration, at which time the brine will be pumped out for processing. This process may be repeated a number of times.

  Much of the information in this Broadview summary has been drawn from the Environmental Impact Statement, by SNC-Lavalin, October 2018, prepared for Canada Golden Fortune Potash Corp., 222p.

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TUGASKE PROJECT

The Tugaske deposit, within the larger Vanguard Project area, is located ~170 km south of Saskatoon, 150 km NW of Regina, ~70 km NW of Moose Jaw and just over 5 km SE of the township of Tugaske.

  Exploration in the Tugaske area commenced with two drill holes in 1963 and 1964 by Sifto Salt Inc. The area was subsequently held by Devonian Potash Inc. who did not apparently conduct any significant exploration before selling its titles to Yancoal Canada Resources Co. Ltd in 2011. The latter drilled two more holes that intersected the potash bearing Prairie Evaporite Formation in October 2012. The second hole was abandoned before retrieving core below the Patients Lake potash member, the uppermost of the 3 such members of the Prairie Evaporite Formation. Yancoal commissioned more than 105 km of 2D seismic surveys on a grid pattern over the Tugaske area in 2012. In April 2016, Gensource Potash Corp. acquired the potash permits from Yancoal which were converted to Potash Leases KL244 and KL255. Gensource has since drilled a further four holes during 2016 to 2019 inclusive to intersect the potash members of the Prairie Evaporite Formation. Reinterpretation of the 2D seismic identified a number of Winnipegosis Formation mounds/banks (see the Geological Setting section above), although none penetrated as high as the potash beds. The Winnipegosis Formation immediately underlies the Prairie Evaporite Formation, and is characterised by reef mounds which form 'basement high' that the lower Prairie Evaporite Formation laps against. A few dissolution collapses structures ('geologic anomalies') were also revealed by the seismic data which were noted for exclusion from the Mineral Resource. The main observation was a major salt dissolution collapse structure in the southern section of the area. In 2017 Gensource undertook a program of 3D seismic focused on a 34.37 km2 portion of KL 245 in the north, to further refine the understanding of the disposition of the evaporite sequence and to define a large enough area to contain an economic mineral resource. The seismic also showed the sequence has a gentle regional dip from NE to SW. In addition it outlined the Prairie Evaporite solution edge to the SW, based on total salt thickness and dip of the Second Red Bed, confirmed by local wells that show thinning and or absence of the Prairie Evaporite and the edge of the overlying Davidson Evaporite.

  The regional geology and setting at Tugaske is as for the other deposits described and outlined above. As in these other deposits, potash at Tugaske occurs in the three significant sylvite-bearing members within the upper half of the Prairie Evaporite Formation, which is part of the Middle Devonian Elk Point Group and is located at a depth of ~1500 m below the surface. These are, in upward progression, the Esterhazy, Belle Plaine and Patience Lake potash members. The Esterhazy member overlies a footwall halite, and is separated from the Belle Plaine Member by a halite interbed that sandwiches a suite of interbedded clay, halite and sylvinite beds known as the White Bear Marker. The Belle Plaine and Patience Lake members are separated by a 2.85 to 3.66 m thick halite bed that sandwiches a 0.3 to 0.67 m thick sylvite bed, the Allan Marker. The Patience Lake Member is overlain by a 5.4 to 10.2 m thick salt back, followed by the Dawson Bay Formation, a dolomitic-dominated formation, that is underlain by the basal red shale of the 'Second Red Beds', and capped by the 'Davidson Evaporite'. The presence of this sequence in full at Tugaske is confirmed by the 4 x Gensource and 2 x Yancoal drill holes.
  Mineralisation within each of the potash members was not deposited as a single event, but rather as a progression of cycles, forming sub-members, each of which is consistent over large areas, and is bounded by clay seam horizons.
  The Esterhazy Member, comprises a very weakly mineralised 1.22 m thick 'Lower' Esterhazy Sub-member that is only found in one of the Sifto Salt drill holes to the north of the main resource. This is followed by a 0.61 m thick intra-Esterhazy Salt, and then by the main 'Upper' Esterhazy that ranges from 6.34 to 10.49 m in thickness, and although quite variable, is found in all drill holes. The 'Upper' Esterhazy is divided into 5 sub-members/cycles, with average thicknesses as follows: EZM1 - 2.02 m; EZM2 - 1.69 m; EZM3 - 1.37 m; EZM4 - 1.23 m; EZM5 - 1.26 m.
  The Esterhazy Salt Back between EZM5 and the White Bear Marker is very variable with a thickness that ranges from 4.32 to 6.18 m.
  The Belle Plaine Floor Salt, is mostly 4.46 to 5.92 m thick, but increases to 11.89 m to the north. It occupies the interval between the Belle Plaine Member and the thin White Bear Marker, situated between the Belle Plaine and underlying Esterhazy Members. The White Bear Marker occurs as an Upper and Lower White Bear in most intersections, and as a single lithological unit in others.
  The Belle Plaine Member, which is divided into 7 sub-members/cycles, has a total thickness that varies from 8.7 to 10.3 m. The uppermost of the sub-members, BLM7 is the salt back to the Belle Plaine Member. It averages 0.39 m in thickness and is composed of halite, separating BLM6 and the Allan Marker, both of which are composed of sylvinite. The average thicknesses of the individual sub-members/cycles is as follows: BPM1 - 1.10 m; BPM2 - 1.82 m; BPM3 - 1.24 m; BPM4 - 2.07 m; BPM5 - 1.67 m; BPM6 - 1.60 m; and BPM7 - 0.39 m.
  The Patience Lake Member is sub-divided into 4 sub-members/cycles and intervening clay seams, and ranges from 9.4 to 15.66, averaging 12.72 m in thickness. The four sub-members average from bottom to top, PLM1 - 3.92 m; PLM2 - 4.32 m; PLM3 - 2.59 m and PLM4 - 2.16 m. Each of these, in turn, vary in thickness, with the minimum of PLM4 being 0.37 m, to the maximum thickness of PLM2 being 6.09 m.

  The dominant constituents of the potash members are halite, sylvite and carnallite, with sylvite being the principal ore mineral. Even in the sylvinite, halite remains the largest constituent. Iron oxide staining is common in the potash members. The only other soluble component of any significance in the Prairie Evaporite Formation is anhydrite. Clay, dominated by Fe-Mg chlorite, illite and Mg-septechlorite, accounts for about one third of the insolubles, occurring as seams and interstitial to the evaporites. Other insolubles in decreasing order of abundance are anhydrite, dolomite, hematite, quartz, K feldspar and hydrocarbons.

Mineral Resources and Ore Reserves as at October, 2021, quoted by Fourie et al. (2021) for the Patience Lake and Belle Plaine Members only, were:
Mineral Resources
  Measured Resource
    1223.8 Mt of in situsylvinite; 1162.6 Mt of sylvinite (modified) @ 35.7 wt.% KCl, for 166.0 Mt of recovered KCl;
  Indicated Resource
    955.3 Mt of in situsylvinite; 859.8 Mt of sylvinite (modified) @ 35.8 wt.% KCl, for 123.1 Mt of recovered KCl;
  Measured + Indicated Resource
    2179.1 Mt of in situsylvinite; 2022.4 Mt of sylvinite (modified) @ 35.7 wt.% KCl, for 289.1 Mt of recovered KCl;
The modified sylvinite tonnage estimates are based on:
  A cut-off of 15% K2O (=24.6% KCl) and a maximum of 6% carnallite;
  No thickness or insoluble cut-off;
  An allowance of 25% for geologic anomalies (including dissolution collapse; leach/depletion, replacement; and washout anomalies as described earlier in this record).
  The recovered KCl assumes that 40% of the available KCl is recovered.
  In calculating these figures the radius of influence for drill holes was 1.5 km for Measured; 2.25 km for Indicated and 6 km for Inferred.

Due to the pervasive presence of carnallite, and lower KCl grades within the Esterhazy Member, no Mineral Resource has been defined for it.

A Proved + Probable Ore Reserve and tonnage of Muriate of Phosphate (MOP = KCl) recovered has been estimated for the PLM1 Sub-member of the Patience Lake Member alone, representing the initial production phase.
  To extract the Proved + Probable Ore Reserve of the PLM1 Sub-member in the mine confines would require a cavern with a volume of 28.7 Mm3 and height of 3.9 m. The recovery of mineralised material from the cavern is estimated to be 61.8%. A factor of 0.93 is also applied to account for unknown 'geologic anomalies'. When these are taken into consideration, it leaves a recoverable cavern volume of 16.5 Mm3, which at an SG of 2.08 amounts to 34.0 Mt of mineralised material. This sylvinite has a weighted mean grade of 42 wt.% KCl;   0.70 wt.% carnallite;   6.4 wt.% insolubles. At these grades, the recoverable mineralised material would yield 14.1 Mt of MOP.

  The solution mining method planned to be applied to extract PLM1 differs from that employed by other mines in Saskatchewan. The planned method is similar to that employed by Intrepid Potash at their Cane Creek Mine in Moab, Utah, USA since 2003 (Ryan, 2012). This method involves drilling a single, east-west oriented, horizontal tail to the vertical injection well, following the footwall contact of PLM1. Then a second, vertical recovery well is drilled, 1400 m to the south of the injection well to intersect PLM1. Seven x ~1400 m long, horizontal, north-south oriented drill holes are then wedged from the recovery/production well, and drilled as a fan, all following the lower contact of PLM1 and intersecting the east-west injection well at their extremities. Each hole of this return/production well fan intersects the injection well 100 m from its neighbours. The area covered within PLM1 by such a configuration comprises a 1400 x 800 m right angled triangle with seven triangular fingers, separated by the drill hole fan. The width of these fingers expands from <1 m in the south at the junction with the main vertical return/production well, to 80 m in the north at the injection well, allowing for a 20 m pillar between each at the intersection with that latter well. The caverns are to be 3.9 m high, the thickness of PLM1. Heated NaCl saturated brine is injected via the injection well and returned along the return/production fan to the main vertical production well to be processed at the surface. This selectively leaches KCl, leaving the NaCl in the sylvitite bed. This selective solution mining is envisaged to have two distinct cavern production phases. The first involves continuous operation until the KCl content of the returned brine wanes. A batch mode is then employed, whereby brine circulation is paused, and the solutions in the caverns are then left to gradually leach more KCl, until levels have risen to economic levels before flushing them to the surface. This process is repeated until production from the solution mining cavern is no longer economic.
  The initial drilling of the caverns is expected to take 12 months with a single rig. The expected individual cavern life is 12.1 years to produce a total of 499 000 t of retrievable MOP/potash. A mosaic of these triangular cavern sets will be established to process the entire resource of PLM1, with adjacent triangles separated by pillars on their adjacent hypotenuses to form a square, etc.

  The information in this Tugaske summary has been largely drawn from Fourie, L., Hambley, D., Atkings, D., Ruel, L., Bernard, D., Blixt, K., Fjeld, S. and Ferguson, M., 2021 - Technical Report Summarizing the Tugaske Project, Saskatchewan; an NI 43-101 Technical Report prepared for Gensource Potash Corp., 174p.

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SOUTHEY PROJECT

  The Southey Project is located ~170 km south of Saskatoon and 60 km north of Regina, in Saskatchewan, Canada. It lies within Sub-surface Mineral Pemits KP377 and 392 with a total area of 782 km2.

As in the other mines and projects of the Saskatchewan Potash Belt, the Southey Project is to exploit potash-bearing salt beds of the Patience Lake, Belle Plaine and Esterhazy Potash Members of the Middle Devonian Prairie Evaporite Formation. See the previous deposite descriptions and Regional geology section above for details of the host stratigraphy and potash beds to be mined. The average depth to the top of the Prairie Evaporite Formation at Southey is 1253 m below the surface. It is overlain and underlain by the full sequence described in the Regional geology section above, and then capped by 350 to 450 m of Cenozoic fluvial and Quaternary glacial cover.

Mineral Resources
  The project is reported to have a total in situ tonnage of 5.089 Gt of sylvinite that contains 1.529 Gt of mineable sylvinite, as follows:
• Measured Resource - 227 Mt
• Indicated Resource - 653 Mt
• Inferred Resource - 649 Mt
  The project is planned to be extracted by solution mining with the methods successfully employed at the currently operating Belle Plaine and Bethune mines, rather than the proposed horizontal cavern techniques used elsewhere. The authors claim that none of the horizontal drilling and mining methods proposed for a number of the other advanced projects in the belt, as described above, have been proven effective for the Saskatchewan ores.

  The sparse geological information available, as included in this Southey summary, has been largely drawn from Golder and Associates, 2015 - Yancoal Canada Resource Company Ltd., Southey Project; a Technical Report prepared for Yancoal Canada Resource Company Ltd., by Golder Associates, 136p.

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UNITY MINE

  The Unity Mine shaft is located near the township of Unity, ~180 km WNW of Saskatoon.

  In 1946, a cored petroleum exploration well near Unity in west central Saskatchewan encountered potash grading 21.6% K2O over a 3.35 m width at a depth of 1056 m below surface (Fuzesy, 1982). This led to work commencing in 1952 on the sinking of the first shaft to conventionally mine potash in what was to become the Saskatchewan Potash Belt. Significant difficulties were encountered in shaft sinking, largely due to inflow of water from the aquifers in the overlying succession, in particular from the poorly lithified sand interbedded with clays and shale at the base of the Early Cretaceous Blairmore Formation, as well as a dozen more aquifers below that. Work was eventually abandoned in 1961, after reaching a depth of 550 m and the shaft was sealed in 1968 without any production having been achieved.
  This shaft represents the north-western extension of the Saskatchewan Potash Belt, being ~165 km WNW of the Cory and Vanscoy mines of the main cluster in the Saskatoon area. Mineralisation appears to be hosted within the Patience Lake Member of the Prairie Evaporite Formation, which is the principal member that extends this far to the NW, although Unity is close to the NW extremity of the Belle Plaine Member, which is probably only poorly developed. The Patience Lake Member has been encountered in petroleum exploration wells for another 175 km to the WNW from Unity, into Alberta, although no further thick, economic intersections have been encountered in that interval.
  Given the continuity of the potash members of the Prairie Evaporite Formation, the thick, high grade intersection encountered in the drill hole at Unity is taken to represent a large potash resource.
  In addition, petroleum exploration during the 1940s discovered thick accumulations of Middle Devonian salt in the Unity area and in 1948, the Unity solution mining operation and plant was built by Sifto Salt, now Compass Minerals International, Inc. Production commenced in 1949, continuing to the present, currently at a rate of 160 000 tonnes of salt per annum.

The information for this Unity summary has been drawn from Cocker, et al., 2023 and a number of other sources.

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The most recent source geological information used to prepare this decription was dated: 2023.    
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd.   Unauthorised copying, reproduction, storage or dissemination prohibited.

Vanskoy

Cory

Patience Lake

Allan

Colonsay

Lanigan

Jansen

Esterhazy K2

Rocanville

Belle Plaine

Bethune (Legacy)

    Selected References
Cocker, M.D., Orris, G.J., Dunlap, P., Yang, C. and Bliss, J.D.,  2023 - Geology and undiscovered resource assessment of the potash-bearing, Middle Devonian (Givetian), Prairie Evaporite, Elk Point Basin, Canada and United States: in    U.S. Geological Survey Scientific Investigations Report 2010-5090-CC    145 p.
Fuzesy, A.,  1982 - Potash in Saskatchewan: in    Saskatchewan Geological Survey, Report 181,    48p.
Gendzwill. D. and Martin, N.,  1996 - Flooding and loss of the Patience Lake potash mine: in    CIM Bulletin   v.89, No. 1000, pp. 62-73.
Halabura, S.P. and Hardy, M.P.,  2007 - An Overview of the Geology of Solution Mining of Potash in Saskatchewan: in    Solution Mining Research Institute; Fall 2007 Technical Meeting, Halifax, Nova Scotia, Canada, 8 - 9 October 2007,    17p.
Nicolas, M.P.B. and Yang, C.,  2022 - Stratigraphy and distribution of the potash-bearing members of the Devonian Prairie Evaporite, southwestern Manitoba (parts of NTS 62F, K): in    Report of Activities 2022, Manitoba Natural Resources and Northern Development, Manitoba Geological Survey,    pp. 87-95.
Nicolas, M.P.B.,  2015 - Potash deposits in the Devonian Prairie Evaporite, southwestern Manitoba (parts of NTS 62F, K): in    Report of Activities 2015, Manitoba Mineral Resources, Manitoba Geological Survey,    pp. 97-105
Staff of the Ministry of Energy and Resources  2023 - Saskatchewan Exploration and Development Highlights 2023: in    Saskatchewan Geological Survey, Sask. Ministry of Energey and Resources, Misc. Rep. 2023-3    21p.
Yang, C., Jensen, G. and Berenyi, J.,  2009 - The stratigraphic framework of the Potash-rich Members of the Middle Ddevonian Upper Prairie Evaporite Formation, Saskatchewan: in   Summary of Investigations 2009, Saskatchewan Geological Survey, Sask. Ministry of Energey and Resources, Misc. Rep. 2009-4.1   v.1, 28p.


Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge.   It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published.   While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants:   i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and   ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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