| Title | Geological setting and origin of microdissemiated Au-Ag-Cu minerals, Fort Mackay region, northeastern Alberta |
| Download | Download (whole publication) |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Abercrombie, H J; Feng, R |
| Source | Exploring for minerals in Alberta: Geological Survey of Canada geoscience contributions, Canada-Alberta Agreement on Mineral Development (1992-1995); by Macqueen, R W (ed.); Geological Survey of Canada,
Bulletin 500, 1997 p. 247-277, https://doi.org/10.4095/209216  Open Access |
| Year | 1997 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| Related | This publication is contained in Exploring for minerals in
Alberta: Geological Survey of Canada geoscience contributions, Canada-Alberta Agreement on Mineral Development (1992-1995) |
| File format | pdf |
| Province | Alberta |
| NTS | 74D; 74E; 74L; 74M; 84A; 84B; 84G; 84H; 84I; 84J; 84O; 84P |
| Area | Fort McMurray; Fort Mackay; Fort Chipewyan; Peace River; Slave River; Wabasca River; Clearwater River |
| Lat/Long WENS | -116.0000 -110.0000 60.0000 56.0000 |
| Subjects | metallic minerals; geochemistry; hydrogeology; stratigraphy; mineralization; gold; silver; copper; hematite; halite; stratigraphic correlations; stratigraphic analyses; sandstones; sedimentary rocks;
alteration; limestones; siltstones; gneisses; metamorphic rocks; chemical analysis; basin evolution; paleotemperatures; gold geochemistry; platinum geochemistry; palladium geochemistry; rhodium geochemistry; calcium geochemistry; paleohydrology;
hydrostratigraphic units; modelling; salt; brine; exploration guidelines; Western Canada Sedimentary Basin; Elk Point Group; Beaverhill Lake Group; Woodbend Group; Mannville Group; Colorado Group; Precambrian; Cambrian; Devonian; Cretaceous |
| Illustrations | sketch maps; stratigraphic columns; photomicrographs; photographs; cross-sections; analyses |
| Program | Canada-Alberta Agreement on Mineral Development, 1992-1995 |
| Released | 1997 10 01 |
| Abstract | Newly discovered gold, silver, copper and related metallic minerals occur in rocks of the Western Canada Sedimentary Basin and underlying Precambrian basement near Fort MacKay, Alberta. The minerals
include microdisseminated native, intergrown, and alloyed metals, and metal-chloride, -oxide, -carbonate, and -sulphide minerals deposited in pores and in microveinlets associated with fractures and diagenetically altered fabrics. Typical alteration
minerals include hematite, microcrystalline quartz, Ce-carbonate, monazite, and native S.
A major structural feature at Fort MacKay is the dissolution edge of the Middle Devonian Prairie Formation, Upper Elk Point Group. Salt dissolution over a
20-30 km wide band paralleling the basin margin caused significant vertical displacement and collapse of overlying sediments. Three hydrochemical zones are recognized: a lower, relatively oxidized, brine regime (>200 000 mg/l; Precambrian, Elk
Point); an intermediate, relatively reduced, saline regime (10 000 to 70 000 mg/l; Beaverhill Lake, Woodbend); and an upper, fresh to brackish regime (1000 to 10 000 mg/l; Mannville and younger), locally bitumen-saturated.
Microdisseminated
polymetallic mineralization is proposed to have occurred by mobilization and transport of gold and other metals in oxidizing, halide-rich brines derived from the Elk Point Group at a maximum paleotemperature of about 90°C. Metal deposition probably
is related to changes in redox potential along the flow path; deposition may, in part, be related to the presence of hydrocarbons. The basin- wide distribution of halite in the Prairie Formation and its removal by dissolution over large areas of the
WCSB may signify regional potential for similar occurrences across western Canada. |
| GEOSCAN ID | 209216 |
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