|Title||Mineral systems with IOCG and affiliated deposits: part 3 - metal pathways and ore deposit model|
Montreuil, J F; Potter, E G; Blein, O; De Toni, A F|
|Source||Geological Association of Canada, Special Paper 52, 2022 p. 89-121|
|Alt Series||Natural Resources Canada, Contribution Series 20210061|
|Publisher||Geological Association of Canada|
|Media||paper; on-line; digital|
|Related||NRCan photo(s) in this
|Province||Canada; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut|
|NTS||1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560|
|Lat/Long WENS||-180.0000 180.0000 90.0000 -90.0000|
|Subjects||Economics and Industry; economic geology; geochemistry; mineralogy; Science and Technology; mineral deposits; metals; iron; iron oxides; facies; Great Bear Basin|
|Illustrations||location maps; photographs; tables|
|Program||Targeted Geoscience Initiative (TGI-6) Digital Geoscience and Method Development Project|
|Released||2022 07 22|
|Abstract||The ascent of voluminous hypersaline fluid plume(s) through the upper crust triggers a succession of fluid-rock reactions that lead to a systematic sequence of iron-oxide and alkali-calcic alteration
facies and a wide variety of mineral deposits. This paper illustrates how these mineralizing systems produce distinct deposit types using the Great Bear magmatic zone (Canada) and global districts. Intense leaching of host rocks during albitization
(Facies 1 with Na and transitional Facies 1-2 with Na-Ca-Fe) recharges fluids with metals. Facies 2 (high-temperature Ca-Fe) alteration hosts iron oxide-apatite (IOA) deposits where high heat sources are available and iron skarn deposits in the
presence of carbonates. Systems that evolve to transitional Facies 2-3 (high-temperature Ca-K-Fe), Facies 3 (high-temperature K-Fe), Facies 4 (high-temperature K/K-Ca-Mg) and Facies 5 (low-temperature K-Fe/Ca-Fe oxidized/Ca-Mg-Fe reduced) can produce
a wide range of polymetallic, iron-rich to iron-poor deposits, including iron-oxide copper-gold (IOCG), critical metal (Co/Bi/Au/REE/U) and skarn deposits. Facies 6 (K, Si, Al) comprises affiliated epithermal and polymetallic vein systems.
Syn-metasomatic magma emplacement, tectonic and volcanic activity, and mixing of external fluids with the main fluid plume can induce a cyclical build-up or telescoping of alteration facies as well as retrogression to higher temperature mineral
assemblages. The thrusting of albitite corridors into shallower or lower temperature fluids can lead to albitite-hosted U and Au-Co±U deposits whereas renewed fluid circulation driven by orogenesis or magmatism can remobilize early metal endowments.
The ore system model is a framework to classify the variety of ore deposits encountered in these systems while providing effective and predictive mapping and exploration tools for IOCG and affiliated deposits, including their critical metal variants.
|Summary||(Plain Language Summary, not published)|
Mineral systems with polymetallic iron oxide copper-gold (IOCG) and affiliated deposits host a large variety of critical metals as reserves and
by-products. This scientific paper is the Part 3 of three chapters that synthesise the global geological and geochemical footprints of these mineral systems to refine ore deposit models for the Special Paper 52 of the Geological Association of Canada
entitled 'Mineral systems with iron oxide copper-gold (IOCG) and affiliated deposits'. Using Parts 1 and 2 results of past GEM/TGI and on-going TGI-6 collaborative research, Part 3 delivers an ore genesis model that illustrates how alteration facies
can be used to predict and explore for the diverse deposit types with critical metals, Cu and Au along the fluid flow paths across systems. Australian and American case examples, including the Olympic Dam Cu-U-Au-Ag deposit, are compared with
Canadian examples, including the Great Bear magmatic zone, to position prospective Canadian settings globally.