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Eskay Creek |
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British Columbia, Canada |
| Main commodities:
Au Ag Zn Cu
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Eskay Creek gold-silver deposit is hosted by felsic volcanic rocks near the top of the Lower to Middle Jurassic Hazelton Group, and lies within the Stikine Arch of north-western British Columbia, Canada.
Published reserve figures are as follows:
Reserves, 1993 - 1.1 Mt @ 65 g/t Au, 2900 g/t Ag, 5.6% Zn, 0.77% Cu (AME, 1994)
Reserves, 1990 - 3.97 Mt @ 26 g/t Au, 998 g/t Ag (Dawson, et al., 1991).
Britton, et al., (1990) quote the following figures:
5.02 Mt @ 15.6 g/t Au, 441 g/t Ag (Reserve, 1989, @ 1.4 g/t Au cut-off),
7.19 Mt @ 17.4 g/t Au, 413 g/t Ag (Reserve, 1989, @ 1.7 g/t Au equiv. cut-off),
1.42 Mt @ 7.2 g/t Au, 117 g/t Ag (Reserve, 21A deposit, @ 1.4 g/t Au cut-off),
3.61 Mt @ 19.2 g/t Au, 566 g/t Ag (Reserve, 21B deposit, @ 1.4 g/t Au cut-off),
0.97 Mt @ 9.6 g/t Au, 127 g/t Ag (Reserve, 21A deposit, @ 3.4 g/t Au cut-off),
1.91 Mt @ 33.6 g/t Au, 1155 g/t Ag (Reserve, 21B deposit, @ 3.4 g/t Au cut-off),
0.184 Mt @ 22.6 g/t Au, 230 g/t Ag (Reserve, 21A deposit, @ 8.6 g/t Au cut-off),
1.223 Mt @ 49.4 g/t Au, 1392 g/t Ag, 5.5% Zn, 2.2% Pb, (Reserve, 21B deposit, @ 8.6 g/t Au cut-off).
At December 1998 21 Zone production + probable and proven reserves were:
1.9 Mt @ 60.2 g/t Au, 2652 g/t Ag, 3.2% Pb, 5.2% Zn, 0.7% Cu (Sherlock et al., 1999)
The Eskay Creek deposit is part of a well known belt of base and precious metals showings that has been explored intermittently since the 1930's. Two deposits, the 21A and 21B, have been delineated at Eskay Creek. Both comprise stratabound massive sulphide lenses within a tuffaceous mudstone unit at the contact between rhyolite and overlying andesite. Disseminated and stockwork mineralisation is also present in immediately underlying rhyolite. In addition, the northern part of the 21B deposit includes two massive sulphide lenses within interflow mudstones of the overlying andesites. The two deposits have distinctly different mineralogies. The 21A is rich in stibnite and realgar, with only minor pyrite and base metals. The 21B lacks stibnite and realgar, but contains abundant sphalerite, tetrahedrite, boulangerite, bournonite, galena and pyrite (Britton, et al., 1990).
The Eskay Creek area was first discovered in 1932 when early prospectors located a line of gossanous bluffs that extended for more than 7 km. Subsequent exploration has been largely for high grade precious metals, predominantly silver, with base metals only being of secondary interest. Early exploration between 1935 and 1938 identified more than 30 distinct mineralised zones, each of which was given a numerical designation. Orpiment and realgar rich boulders, with high Au and Ag values, were located in trenches on the northern margin of the #21 prospect in the late 1930's. These were not followed up. Investigations continued in 1939 and after World War II, with #5, #6, #21, #22 and #28 being the main target areas. Between 1946 and 1976 several thousand metres of diamond drilling was undertaken, and adits, crosscuts, trenches and open cuts were excavated and sampled by a number of companies. In 1971 a 1.5 t sample was collected, yielding 9.3 g Au, 7435 g Ag, 29 kg Pb and 42.7 kg Zn from trenches on the #22 zone, while in 1979 these trenches were mined for 8.75 t of hand-cobbed ore which yielded 1.263 kg Au, 25.49 kg Ag, 412 kg Pb and 1.008 kg Zn (Britton, et al., 1990).
In the early 1980's a geochemical survey was undertaken in the area by US Borax, followed by shallow diamond drilling. In 1985 four diamond drill holes were drilled in the #21 open cut area by Kerrisdale Resources Limited. These identified a new zone of spotty gold and silver values hosted by altered felsic volcanics. The best intersection was 5 m @ 3.4 g/t
Au, 1342 g/t Ag. Calpine Resources Inc. optioned the property in 1988 and carried out a geochemical soil sampling project. On the basis of this work a five hole program was planned to test the #21 open cut and probable extensions. Three holes, numbers 2,4 and 5, intersected stockwork mineralisation in rhyolite. Two 50 m step-out holes, numbers 2 and 6, intersected a massive sulphide body above the target, at the contact between the rhyolite and overlying andesite. Hole 6 cut 29 m of stibnite and realgar rich core with 26 g/t Au, 38 g/t Ag, including 16 m @ 46 g/t Au, 68 g/t Ag. Ten additional holes for 2099 m of drilling were subsequently completed. In January 1989 a winter delineation drilling program was commenced with 54 holes totalling 13 368 m of drilling. This outlined the 'South Zone', or 21A deposit, and suggested the presence of more blind mineralisation further to the north. Drilling resumed in June of 1989, 1 km to the north of hole 6. This included hole number 109 which cut 61 m @ 99 g/t Au, 29 g/t Ag, including 19 m @ 266 g/t Au, 46 g/t Ag. By December 1989 a total of 29 550 m of drilling was completed in this new zone, as holes 71 to 205, outlining the 21B deposit. By the end of March 1990 the total drilling had risen to 44 970 m in 235 holes (Britton, et al., 1990).
Geology
The Eskay Creek orebody lies on the western margin of the Intermontane tectonic belt, and is entirely within the Stikinia Terrane. See the Regional Setting section of the Brucejack record for more detail of the geology and setting of the district. The regional stratigraphic framework in this part of Stikinia comprises: 1). the Palaeozoic Stikine Assemblage - represented in the Eskay Creek district by Permian and older volcanics and shelf sediments; 2). Triassic to Jurassic volcanic/plutonic complexes, which are more than 5000 m thick in the vicinity of Eskay Creek; 3). middle and upper Jurassic marine sediments of the Bowser Basin overlap assemblage, followed by folding, faulting and weak metamorphism in the Cretaceous; and 4). the Tertiary Coast Plutonic Complex. The Coast Complex, which is to the west, embraces dioritic to granitic rocks which represent at least four episodes spanning the period from the Triassic to Tertiary. Remnant Pleistocene to Recent basalts are also locally preserved (Britton, et al., 1990).
The regional sequence around Eskay Creek is as follows, from the base (Britton, et al., 1990):
Palaeozoic, represented by,
• Permian and older Stikine Assemblage - which outcrop 15 km to the north-west of Eskay Creek and comprise phyllite, siliceous siltstone, ribbon chert, tuffaceous wacke and foliated plagioclase porphyry. Limestone, felsic tuff and basaltic pillow lava are found further to the west.
Mesozoic, comprising:
• Upper Triassic Stuhini Group - commencing with immature clastics which have volcani-clastic interbeds, while limestone lenses are found to the south and west. The upper sections of the unit are marked by a distinctive granite cobble conglomerate.
• Upper to Middle Jurassic Hazelton Group, subdivided into:
Unuk River Formation (or Andesitic Sequence) - a thick, monotonous sequence of fine grained andesitic pyroclastics and flows with tuffaceous turbidite, wacke and conglomerate interbeds. This unit has not been observed at Eskay Creek.
Betty Creek Formation (or Pyroclastic-Epiclastic Sequence) - a heterogeneous sequence of vari-coloured andesitic to dacitic tuffs and flows, interbedded with volcanic derived sedimentary rocks and columnar jointed dacites. Epiclastic and volcaniclastic members are locally hematitic. Both subaerial and subaqueous deposition is indicated.
Mount Dilworth Formation (or Felsic Volcanic Sequence) - which comprises a thin, but widespread sequence of felsic pyroclastics and lesser welded tuffs which cap the Betty Creek Formation. These rocks are typically white weathering, or rusty where pyritic, and waxy white to grey, dacitic ash and lapilli tuffs with centimetre scale bedding. The unit is traceable over a wide area and is a host to many base and precious metal showings. It represents the terminal stage of the volcanism of the Stewart Complex.
Salmon River Formation (or Siltstone Sequence) - a thick sequence of mainly turbiditic siltstone and fine sandstone with rare conglomeratic, tuffaceous and volcanic interbeds. The basal member is a coarse pyritic, fossiliferous, calcareous wacke, typically <2 m thick. The upper member has three main facies, namely 1). a striped eastern facies of black, cherty, radiolarian shale and white weathering reworked felsic tuffs, 2). the medial Eskay Creek facies composed of limestone, limy or cherty siltstone and shale which interfinger with and overlie thick pillow lava and pillow lava breccia The contact with the overlying Bowser Basin sequence is transitional, and 3). a speculative western facies.
• Middle to Upper Jurassic Bowser Lake Group - largely present as the Ashman Formation, composed of a thick sequence of thinly bedded siltstone, shale and sandstone with thin lenses and sheets of chert pebble conglomerate.
Pleistocene and Recent, comprising remnants of basaltic flows and tephra.
Intrusives, which include a series of plutons, sills, dykes and dyke swarms that range from late Triassic to Oligocene in age. The oldest are late Triassic diorites. The closest to Eskay Creek are Jurassic diorite stocks and conformable dioritic sheets. The Coast Complex is represented by Eocene granitic rocks 30 km to the west, with other dyke swarms (Britton, et al., 1990).
In the immediate Eskay Creek area the stratigraphy is as follows, from the base (Britton, et al., 1990):
• Lower Volcano-sedimentary Unit, >100 m thick - mixed andesitic to dacite volcanic rocks and immature, fine to medium grained sediments which contain lower Jurassic fossils.
• Footwall Dacite Unit, >100 m thick - a drab grey to white dacite tuff, tuffaceous wacke and mudstone. The dacitic volcanics are predominantly tuff and ash flow tuff, with lesser lithic tuff and breccia. Fragmental rocks are locally heterolithic with clasts of dacite, porphyritic felsite and mudstone. Intercalated epiclastics are thick to thin bedded, grey to black, tuffaceous wacke and mudstone, and are commonly pyritic. The upper contact may be unconformable. This may be a correlate of the Betty Creek Member, as described above.
• Rhyolite Unit, 30 to 110 m thick - a grey to white aphyric breccia, tuff-breccia, lapilli tuff and tuff, with subordinate massive rhyolite lava. Thin intercalations of mudstone and waterlain tuff occur locally. Rhyolite fragments are flow banded, while the matrix is tuffaceous. Overall the unit is thin bedded and monotonous. Within the mineralised zone it is altered to an assemblage of quartz, muscovite and chlorite which obscure the primary textures. It has been correlated with the Mount Dilworth Formation described above.
• Contact Unit, 2 to 60 m thick - an areally restricted basal member of rhyolite breccia that grades into a widespread upper member of carbonaceous mudstone. The basal member has angular to sub-rounded clasts of rhyolite, chert, mudstone and mineralised and altered fragments, all set in an argillaceous matrix. The upper member is a carbonaceous, pyritic and locally tuffaceous, laminated, black mudstone. The mudstone is composed of numerous quartz eyes, highly altered tuff particles and rare calcareous clasts, set in a matrix of extremely fine grained quartz. An opaque hydrocarbon residue, possibly pyrobitumen, is ubiquitous. Near sulphide lenses the rocks are altered to chlorite, muscovite and calcite. The lower contact of the unit is gradational while the upper is sharp. It is however, indistinguishable from the interflow mudstone beds of the Hangingwall Andesite. This unit has been correlated with the lower member of the Salmon River Formation.
• Hangingwall Andesite, >150 m thick - a flow and sill complex composed of rusty brown weathering, light grey to dark green pillow breccias with subordinate massive flows, dykes or sills, and hyaloclasite bands. The andesite ranges from aphanitic to medium grained and locally carries fine feldspar phenocrysts. It is locally amygdaloidal. The matrix to the breccias is composed of a mix of volcanic fragments, grey calcite, black chert and limy mudstone. Thin mudstone units occur as interflow sediments.
• Upper Sedimentary Unit, >100 m thick - a thick unit of thin bedded, turbiditic, siltstone, shale and fine sandstone and includes strata of the Salmon River and Ashford Formations.
Intrusives are rare in the immediate vicinity of Eskay Creek. Approximately 1 km to the east of the #21 Zone a small body of feldspar porphyry is weakly mineralised along its contact with lapilli tuff. It crops out over an area of around 1000 x 200 m and has the composition of a granodiorite porphyry. It may be related to the higher dacitic pyroclastics. Andesitic dykes and sills might similarly be related to the overlying andesites of the Hangingwall Andesite unit.
Structure
The major structure on the property is an asymmetric, shallow north plunging and north-east trending anticline which closes to the north. Interbedded volcanic and sedimentary strata dip at 70 to 20° on the north-west limb (Britton, et al., 1990).
The anticline is broken by a series of high angle faults. Major faults strike NNE, minor ones NNW. Several northerly to north-east trending lineaments also traverse the property, some are faults, others fractures (Britton, et al., 1990).
Mineralisation and Alteration
Mineralisation is present as both stratabound and transgressive styles.
Stratabound mineralisation is represented by: 1). stratabound gold and silver, with antimony, arsenic and mercury minerals associated with intense alteration within the Contact Unit, eg. the #21A deposit; 2). stratabound sphalerite rich mineralisation with high grade gold and silver in tuffaceous facies of the Contact Unit, eg. the Southern #21B deposit; 3). stratabound gold and silver rich base metal sulphide lenses within interflow mudstone beds of the Hangingwall Andesite Unit, eg. the Northern #21B deposit (Britton, et al., 1990).
Transgressive mineralisation is present as: 1). disseminated and fissure vein gold, silver, lead, zinc mineralisation with minor antinomy and arsenic associated with variable muscovite within the Rhyolite Unit, eg. stockworks between the stratabound mineralisation of the #21A and #21B deposits; 2). disseminated to massive sulphides with low grade gold and silver veins and shears within the Footwall Dacite. Sphalerite, galena and iron sulphides are associated with moderate chlorite, muscovite and silica alteration, eg. the North End of the Eskay Creek workings; 3). Disseminated, geochemically anomalous gold and silver associated with iron sulphides in silicified zones in the Footwall Dacites, eg. the #1 and #5 areas at Eskay Creek; 4). low grade gold and silver associated with minor base metal (Zn, Pb, Fe) sulphides, chlorite and quartz in shears along the contact of the feldspar porphyry plug, approximately 1 km to the east of the #21 zone (Britton, et al., 1990).
The #21 zone is the main focus of economic interest, comprising the #21A and #21B deposits, although significant mineralisation is known in other of the prospects also. The bulk of the mineralisation in the #21 deposits is present as a stratabound sheet within carbonaceous mudstones of the Contact Unit and in underlying rhyolite breccia of the Rhyolite Unit, while the Hangingwall Andesite Unit is mostly barren. In the north however, sulphide layers are also found in mudstone interbeds within the Hangingwall Andesite Unit. As traced by diamond drilling the mineralisation extends over a strike length of 1400 m, 250 m down dip and is 5 to 45 m in thickness (Britton, et al., 1990).
There is both lateral and vertical zoning of the mineralisation. Sb, As and Hg rich mineral assemblages are found to the south, changing to a Zn, Pb and Cu association in the north. Vertical zoning is expressed as a systematic increase in Au, Ag and base metal content up-section (Britton, et al., 1990).
Based on mineral associations and grade continuity the #21 zone has been divided into two deposits. The southern #21A orebody and the central and northern #21B deposits are separated by 140 m of weak mineralisation. In addition two other zones are known at the #21 zone, namely the #21C and the Pumphouse deposits. The #21C is 450 m to the north of #21A and comprises a discrete zone 100 m down dip of #21B, and sub-parallel to it composed of stratiform to discordant barite rich mineralisation in Contact Mudstone and as disseminated mineralisation in rhyolites. The Pumphouse zone is immediately east of the southern end of #21B (Britton, et al., 1990) and is discordant and stratiform, vein and disseminated mineralisation in rhyolite, and bedded to massive sulphides in Contact Mudstone (Sherlock et al., 1999).
The #21A Deposit - is contained within the Contact (Mudstone) Unit and underlying Rhyolite Unit. The known orebody has a strike length of 280 m, is up to 100 m wide and has an average thickness of 10 m. Locally greater thicknesses are observed, such as one drill hole that intersected 34.5 m @ 14.9 g/t Au and 103 g/t Ag. The upper limit of mineralisation is sharp and generally coincides with the basal contact of the Hangingwall Andesite Unit, the bottom 0.5 m of which may show weak alteration. The lower boundary is an assay limit, and is not defined by a lithological contact. Instead it is marked by a decrease in the sulphide content and alteration intensity (Britton, et al., 1990). The deposit can be divided into an:
• Upper stratabound zone of disseminated, to near massive, stibnite and realgar within the Contact Mudstone Unit. These are accompanied by high grade,>15 g/t Au and Ag and occur in variably sheared, carbonaceous mudstone and mudstone rhyolite breccia. Zones of nearly massive stibnite, realgar and orpiment pass along strike and down dip into disseminated domains where sulphides occur in veinlets, as feathery masses, or as heavy impregnations along shears, or in the mudstone matrix. The breccia matrix is variably pyritic, while both breccia matrix and clasts contain needles of stibnite and arsenopyrite. Gold occurs in the native form, as amalgam and possibly as mercurian wurtzite. Silver occurs as the native metal, amalgam, tetrahedrite and un-named Ag-Pb-As-S minerals (Britton, et al., 1990).
Mineralisation is associated with areas of intense alteration. The Contact unit is overprinted by varying amounts of magnesian chlorite, muscovite, chalcedonic silica, calcite and dolomite, while pyrobitumen is ubiquitous. The magnesian chlorite is locally rich in fluorite, the muscovite in barium. There is a diversity of texture despite the relatively uniform mineralogy. Thin sections indicate co-existing zones of high and low strain. Muscovite, chlorite and sulphides display schistosity fabrics with pressure shadows and rotated grains as well as delicate, randomly oriented intergrowths. These zones imply mineral deposition spanning repeated episodes of shearing and alteration (Britton, et al., 1990).
This mineralisation includes the HW zone at the northern end of the 21B zone, within the upper parts of the Contact Mudstone, above the Main stratabound ore, usually above the first basaltic sill, occurring as massive pyrite, sphalerite, galena, chalcopyrite and tetrahedrite. It has a much higher copper and lower precious metal content compared to the main 21B ore zone (Sherlock, et al., 1999).
• Lower stockwork zone of disseminated to micro-fracture filling mineralisation, hosted by the Rhyolite Unit, and comprising tetrahedrite, pyrite, sphalerite and galena, with minor aktashite and chalcopyrite. Realgar and orpiment are rare to non-existent, while carbon and graphite are absent. This style is characterised by low to moderate grades of the tenor of 1 to 15 g/t Au and locally high Ag, associated with base metal sulphides and minor to trace Sb, As and Hg minerals (Britton, et al., 1990).
Beneath the stratabound mineralisation of the Contact Unit, the Rhyolite Unit is strongly fractured and intensely altered. The tenor of fracturing, degree of alteration and levels of metals appears to increase upwards towards the base of the Contact Unit. Within 3 to 4 m of this contact, rhyolite hosted mineralisation is characterised by either 1). massive chlorite-gypsum-barite rock or by 2). quartz-muscovite-sulphide breccia. Both are strongly sheared and foliated, passing rapidly into open space filling vein-breccia textures. Below this zone, fracturing in the Rhyolite Unit decreases dramatically, alteration minerals are restricted to open joints and fractures and sulphide minerals occur as crystalline aggregates on fracture surfaces (Britton, et al., 1990).
The stockwork mineralisation is found in three zones, namely the Pumphouse, Pathfinder and 109 Zones. The 109 Zone is a distinctive, very precious metal rich zone of quartz veins with coarse grained, zoned sphalerite galena, minor pyrite and chalcopyrite with banded crustiform quartz-sulphides. They locally carry black amorphous carbon. Gold and silver are in electrum and sulfosalts (Sherlock et al., 1999)
• Mineralisation within the Footwall Dacite Unit - does not contribute to the reserves, but consists of semi-massive to disseminated, crystalline, pyrite, sphalerite, tetrahedrite, galena and chalcopyrite in a pink to buff, feldspathised rock cut by chlorite and pyrite filled fractures. Lodes carry geochemically anomalous to modest tenor Au and Ag values. This style of mineralisation accounts for a number of the mineralised zones of the Eskay Creek area (Britton, et al., 1990).
The #21B Deposit - is approximately 900 m long, 60 to 200 m wide and locally in excess of 40 m thick. In 1989 it was open in more than one direction.
The southern most 600 m is characterised by high grade stratabound Au and Ag bearing base metal sulphide layers. A representative drill hole in this section intersected 11 m @ 203 g/t Au, 6574 g/t Ag, 14.1% Zn, 6.2% Pb and 1.8% Cu. Banded sulphide mineralisation occurs in carbonaceous and tuffaceous mudstones of the Contact Unit. Sulphides form disseminated, semi-massive and massive laminae and bands, up to 12 m thick, that appear to parallel the bedding in mudstones. The sulphide beds exhibit abundant slump structures, grading and contain tuffaceous debris. The contained sulphides in decreasing order of abundance are: amber sphalerite, tetrahedrite, boulangerite and bournonite with minor pyrite and galena. Gold and silver occur as 5 to 80 µm grains of electrum within fractured sphalerite, commonly in contact with galena. Realgar and stibnite are absent. Gangue minerals include magnesian chlorite, muscovite and quartz, with lesser dolomite and calcite. Peripheral to, and beneath the banded sulphide mineralisation are areas of microfracture veinlets and disseminations within the Rhyolite Unit. These contain tetrahedrite, pyrite and minor boulangerite. The associated gangue comprises magnesian chlorite, muscovite, K-feldspar and calcite. This footwall mineralisation is volumetrically insignificant compared to that below the #21A deposit (Britton, et al., 1990).
The northern 300 m of the #21B deposit exhibits considerable structural and geological complexity. While the sequence is comparable to the southern section of the orebody, mineralisation is found at a number of stratigraphic positions. Gold, silver and base metals occur in two hangingwall unit interflow mudstone beds, as well as in the Contact Unit mudstone and underlying Rhyolite Unit breccias. Very high grade mineralisation is found deeper in the Rhyolite Unit in association with cross-cutting zones of fracture related alteration. The mineralised zone is thick and is cut by zones of strong shearing. The two mineralised hangingwall mudstone beds are partially stacked and are characteristically composed of near massive, dark sphalerite, galena and tetrahedrite, with lesser amounts of pyrite and chalcopyrite. This mineralisation is associated with pervasive chlorite alteration and locally heavy barite developments. Mineralised intervals range from sulphide breccias, to banded sulphides to sulphide mylonite (Britton, et al., 1990).
Mineralisation and alteration in the Contact Unit is similar to that in the southern section of the deposit, as described above. Mineralised textures vary from crudely banded massive sulphides, to thick and thin sulphide bands intercalated with mudstones, with a wide variety of clastic to laminated textures. Cross-cutting mineralisation in the Contact and Rhyolite Units occurs as siliceous (quartz-healed) and carbonate rich breccias. These breccias contain anastomosing, crustiform veinlets and disseminations of coarse grained, iron rich sphalerite and fine grained pyrite, with minor galena, chalcopyrite and tetrahedrite. Gold occurs as spectacular films, wires or blebs associated with fractured sphalerite.
The #21B orebody has returned spectacular intersections such as 208 m @ 29.96 g/t Au, 33.2 g/t Ag, 2.3% Zn, 1.1% Pb, including an upper interval of 3 m @ 23 g/t Au, 1161 g/t Ag, 16.1% Zn, 6% Pb. The combined Contact and Rhyolite Units intercept below this upper interval was 61 m @ 98.6 g/t Au, 29.1 g/t Ag, 3.4% Zn and 1.9% Pb (Britton, et al., 1990).
A zone of shearing and fracturing which is up to 60 m wide (the Pathfinder Fault) cuts the northern #21B deposit. It is marked by intense silica and carbonate alteration that obliterates most original rock textures.
The host rocks of the #21 orebodies are palaeontologically dated at lower to early-middle Jurassic age. Pb isotope analyses of galena samples indicate similarities with other volcanic hosted and porphyry deposits in the region of the western Stikinia Terrane, indicating a widespread early Jurassic mineralising event in the region (Britton, et al., 1990).
For detail consult the reference(s) listed below.
The most recent source geological information used to prepare this decription was dated: 1999.
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.
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Childe F 1996 - U-Pb geochronology and Nd and Pb isotope characteristics of the Au-Ag-rich Eskay Creek volcanogenic massive Sulfide deposit, British Columbia: in Econ. Geol. v91 pp 1209-1224
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MacDonald A J, Lewis P D, Thompson J F H, Nadaraju G, Bartsch R D, Bridge D J, Rhys D A, Roth T, Kaip A, Godwin C I, Sinclair A J 1996 - Metallogeny of an early to middle Jurassic arc, Iskut River area, northwestern British Columbia: in Econ. Geol. v91 pp 1098-1114
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Sherlock R L, Roth T, Spooner E T C, Bray C J 1999 - Origin of the Eskay Creek precious metal-rich volcanogenic massive Sulfide deposit: fluid inclusion and stable isotope evidence: in Econ. Geol. v94 pp 803-824
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