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Highland Valley, Lornex, Highmont, Valley Copper, JA, Bethlehem, Krain, Craigmont |
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British Columbia, Canada |
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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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Summary
The Highland Valley complex comprises a series of large low grade hypogene porphyry copper-molybdenum deposits within calc-alkalic intrusives in central British Columbia, Canada. Like most of the 'porphyry' deposits in western Canada, it occurs within one of the Palaeozoic to Mesozoic displaced terranes accreted onto the western margin of the Canadian Shield, in contrast to those of the western US which are within cratonic terranes. This mine was, in 1998, the only significant 'porphyry' operation in the Canadian Cordillera. The total reserve + historic production amounted to around 2000 Mt @ 0.45% Cu, and included the Lornex, Highmont, Valley Copper, JA, Bethlehem, Krain and Craigmont deposits. The mineralisation is located within the core of the 1000 km2, 210 to 200 Ma Jurassic Guichon Creek Batholith, a multiphase body ranging in composition from tonalite to diorite to granodiorite. This batholith cuts a co-magmatic andesite pile and falls within the Quesnellia Displaced Terrane. Mineralisation is associated with swarms of younger dykes within the youngest, most acid phase of the batholith. In 1994 some 44.7 Mt of ore averaging 0.42% Cu was milled for 186 800 t Cu, 30 t Ag and 0.2 t Au. The mine was (at that stage) operated by Highland Valley Copper, a joint venture between Cominco Ltd, Rio Algom Ltd, Teck Corp and Highmont Mining. In 2020 the operation was 100% owned by Teck Resources Limited and had a production capacity of 115 000 to 120 000 tonnes of Cu per annum.
Geological Setting & Overview
The Highland Valley group of deposits are hosted by the Lower Jurassic Guichon Suite of calc-alkaline intrusives within the Quesnellia Terrane of the south-eastern Intermontane Belt in British Columbia, Canada.
Highland Valley Group of Mines, which includes mines that have operated since 1962 contain.
Remaining Reserves, 1993 - 595 Mt @ 0.42% Cu (AME, 1994).
Total Production+Reserve, 1984, 2000 Mt @ 0.45% Cu equiv. (Dawson, 1991).
Remaining Proved+Probable Reserves 31 Dec, 2018 - 535.5 Mt @ 0.30% Cu (Teck website, 2020).
Remaining Measured+Indicated+Inferred Resources 31 Dec, 2018 - 1287.2 Mt @ 0.26% Cu (Teck, 2020).
The individual deposits of the operation contained:
Lornex* - 577 Mt @ 0.39% Cu, 0.013% Mo (includes production of 228 Mt).
Highmont* - 123 Mt @ 0.25% Cu, 0.024% Mo (includes prod. of 35 Mt).
Valley Copper* - 565 Mt @ 0.48% Cu (includes prod. of 17 Mt).
790 Mt @ 0.48% Cu (Res. 1976, Osatenko & Jones, 1976).
JA* - 286 Mt @ 0.43% Cu, 0.017% Mo
Bethlehem - 144 Mt @ 0.48% Cu (includes prod. of 106 Mt) - including,
East Jersey - 3.4 Mt (Total Prod. Briskey & Bellamy, 1976).
Jersey - 60 Mt @ 0.46% Cu (Prod.+Res., Briskey & Bellamy, 1976).
Huestis - 25 Mt @ 0.45% Cu (Prod.+Res., Briskey & Bellamy, 1976).
Iona - 12 Mt @ 0.47% Cu (Total Res., Briskey & Bellamy, 1976).
Krain - 15 Mt @ 0.55% Cu, 0.02% Mo (Res. 1976, Drummond & Godwin, 1976).
Craigmont*- skarn 33.7 Mt @ 1.77% Cu, 19% Fe (Prod. 1961-82).
* Un-attributed figures as at 1984, from Dawson, (1991)
The Guichon suite are largely confined to, and characteristic of the Quesnellia Terrane, being distributed over a length of more than 1000 km along the Cordillera. They are generally dated at 210 to 200 Ma in the upper Triassic, although some may be as old as 217 Ma, and show a close temporal and spatial relationship to upper Triassic to lower Jurassic volcanics, the Nicola Assemblage. (Woodsworth, etal., 1991). The Nicola Assemblage generally comprises calc-alkaline andesite, dacite, and rhyolite sub-aerial flows and ignimbrites, with relatively alkaline augite porphyry flows, analcite trachy-basalt and trachy-andesites and minor limestones, shale and quartzite (Wheeler and McFeely 1991). All of the deposits above are within the Guichon Creek Batholith, a member of the Guichon suite of intrusives.
In the vicinity of the Guichon Creek Batholith in the Highland Valley, the Nicola Group are predominantly volcanics on the northern rim of the batholith, while sediments predominate on the east, south and western margins. The volcanic rocks are predominantly basalts and basaltic andesites, with locally abundant breccias and agglomerates. The sedimentary rocks include chert, siltstone, sandstone, greywacke, limestone and volcanic conglomerate which grades to sedimentary volcanic breccia. This sequence overlies the Permo-Carboniferous sedimentary and volcanic rocks of the Cache Creek Group, with which they may only be differentiated on fossil evidence. The Cache Creek sediments include chert, conglomerate, grit, greywacke, tuff and some quartzite (McMillan, 1976)
The batholiths of the Guichon Suite are usually elongated in a NNW direction, suggesting structural control by pre- or syn-plutonic faults. In general they are hornblende rich and mesocratic, with granodiorite being the most abundant lithology (Dawson, etal., 1991).
The Guichon Creek Batholith near Kamloops, which hosts all of the deposits listed above, covers around 1000 km2. Gravity data suggests that the outcrop plan represents the lip of a 4 km thick tilted champagne glass which leads down to a stem more than 8 km deep. Reliable K-Ar isotopic dating of the mineralisation ranges from 231 to 196 Ma, while the intrusive yields a late Triassic age of 205 Ma, indicating intrusion over a short period (Woodsworth, etal., 1991).
Sequential radially inward emplacement of four heterogeneous phases within this batholith is indicated by field relationships, with gradational interphase contacts which are rarely intrusive. It has been subdivided into four phases as follows: 1). The outer and oldest, the Border, or Hybrid Phase, is well foliated tonalite and minor hornblende, mafic diorite, quartz-diorite and quartz-monzodiorite, and carries country rock inclusions in its outer sections and as a consequence of contamination, ranges from amphibolite to monzonite in composition; 2). The Highland Valley Phase, which comprises the Guichon (quartz diorite to granodiorite which normally contains 15% mafic minerals, mainly hornblende and biotite which are present in equal amounts, but distributed as clusters) and the Chataway varieties (normally a granodiorite, with 12% evenly distributed mafics, which are predominantly hornblende and minor biotite). The two varieties have intercalated, gradational contacts which are not intrusive; 3). the Bethlehem Phase, which is also a granodiorite, is characterised by 8% mafic minerals, with several percent of coarse grained hornblende in a matrix containing fine evenly distributed, fine to medium mafic crystals. The Skeena Variety is also a granodiorite with a similar composition, occurring in the south of the main Bethlehem Phase; 4). The Bethsaida Phase, which varies from quartz monzonite to granodiorite and has a gradational boundary with the Bethlehem Phase. This forms the innermost, youngest and most leucocratic core is unfoliated and porphyritic (McMillan, 1976).
A swarm of porphyry dykes, which are younger than the Bethlehem Granodiorite, extends northwards from Highland Valley, and comprises a zone which includes the Bethlehem and Krain deposits. Textural and chemical similarities suggest these dykes are derived from the Bethlehem phase. South from Highland Valley, on the same trend, dykes and small plugs cut the Skeena Variety of the Bethlehem Phase. At least in some localities in this southern section the porphyries are offshoots of the Bethsaida Phase, and some, although they are related to it, also cut the Bethsaida Phase (McMillan, 1976).
Proceeding from the rim to the centre of the batholith, the age, colour, SG and magnetic susceptibility normally decrease, while the grain size and acidity increase (McMillan, 1976). Muggeridge & Price (1993) noted that from the margins to the centre of the batholith there were trends from 1). dioritic to granodioritic composition; 2). rocks go from equi-granular to porphyritic; 3). the average grain size increases from about 2 mm in the border phase to 5 to 6 mm in the Bethsaida Phase; 4). the fracture density increases from 1 per 5 to 10 m in the Border Phase, to 1 per metre in the Chataway Variety to 2 to 3 per metre in the central Skeena Phase, while fracture density in the Valley Pit exceeded 10 per metre.
Copper and copper-molybdenum showings are dispersed through the batholith, but the important deposits are associated with late dyke swarms to the north of Highland Valley, or occur in or near the contact of the Bethsaida (the youngest) phases and related dykes. Thus implies that the deposits north of Highland Valley at Bethlehem and Krain, which are predominantly Cu with negligible Mo, are post-Bethlehem but pre-Bethsaida phase, while that to the south, namely Highmont, Lornex, Valley Copper and JA, which are both Cu and Cu-Mo are younger than the Bethsaida Phase (McMillan, 1976; Woodsworth, etal., 1991).
See also records for Valley Copper,
Lornex,
JA,
Krain,
Bethlehem and
Highmont.
For detail consult the reference(s) listed below.
The most recent source geological information used to prepare this decription was dated: 1998.
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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Alva-Jimenez, T., Tosdal, R.M., Dilles, J.H., Dipple, G., Kent, A.J.R. and Halley, S., 2020 - Chemical Variations in Hydrothermal White Mica Across the Highland Valley Porphyry Cu-Mo District, British Columbia, Canada: in Econ. Geol. v.115, pp. 903-926.
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Byrne, K., Lesage, G., Gleeson S.A., Piercey, S.J., Lypaczewski, P. and Kyser, K., 2020 - Linking Mineralogy to Lithogeochemistry in the Highland Valley Copper District: Implications for Porphyry Copper Footprints: in Econ. Geol. v.115, pp. 871-901.
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Byrne, K., Trumbull, R.B., Lesage, G., Gleeson, S.A., Ryan, J., Kyser, K. and Lee, R.G., 2020 - Mineralogical and Isotopic Characteristics of Sodic-Calcic Alteration in the Highland Valley Copper District, British Columbia, Canada: Implications for Fluid Sources in Porphyry Cu Systems: in Econ. Geol. v.115, pp. 841-870.
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Casselman M J, McMillan W J, Newman K M 1995 - Highland Valley porphyry copper deposit near Kamloops, British Columbia: A review and update with emphasis on the Valley deposit: in Schroeter T G (Ed), Porphyry Deposits of the Northwestern Cordillera of North America Can. Inst. of Min. Met & Pet. Spec Vol 46 pp 161-191
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DAngelo, M., Alfaro, M., Hollings, P., Byrne, K., Piercey, S. and Creaser, R.A., 2017 - Petrogenesis and Magmatic Evolution of the Guichon Creek Batholith: Highland Valley Porphyry Cu ±(Mo) District, South-Central British Columbia: in Econ. Geol. v.112, pp. 1857-1888.
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Fleet M E, Seller M H 1997 - Rare earth elements, protoliths, and alteration at the Hemlo Gold deposit, Ontario, Canada, and comparison with argillic and sericitic alteration in the Highland Valley Porphyry district, British Columbia, Canada: in Econ. Geol. v92 pp 551-568
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Lee, R.G., Byrne, K., DAngelo, M., Hart, C.J.R., Hollings, P., Gleeson, S.A, and Alfaro, M., 2021 - Using zircon trace element composition to assess porphyry copper potential of the Guichon Creek batholith and Highland Valley Copper deposit, south-central British Columbia: in Mineralium Deposita v.56, pp. 215-238.
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Lee, R.G., Plouffe, A., Ferbey, T., Hart, C.J.R., Hollings, P. and Gleeson, S.A., 2021 - Recognizing porphyry copper potential from till zircon composition: a case study from the Highland Valley Porphyry District, South-Central British Columbia: in Econ. Geol. v.116, pp. 1035-1045.
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Logan, J.M. and Mihalynuk, M.G., 2014 - Tectonic Controls on Early Mesozoic Paired Alkaline Porphyry Deposit Belts (Cu-Au ± Ag-Pt-Pd-Mo) Within the Canadian Cordillera : in Econ. Geol. v.109, pp. 827-858.
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McMillan W J, 2005 - Porphyry Cu-Mo Deposits of the Highland Valley District, Guichon Creek Batholith, British Columbia, Canada: in Porter, T.M. (Ed), 2005 Super Porphyry Copper & Gold Deposits - A Global Perspective, PGC Publishing, Adelaide, v.1 pp. 259-274
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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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