|Title||The B26 Cu-Zn-Ag-Au project, Brouillan volcanic complex, Abitibi greenstone belt, part 1: geological setting and geochronology|
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|Licence||Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences.|
|Author||Fayard, Q; Mercier-Langevin, P; Wodicka, N; Daigneault, R; Perreault, S|
|Source||Targeted Geoscience Initiative 5: contributions to the understanding of Canadian gold systems; by Mercier-Langevin, P (ed.); Lawley, C J M (ed.); Castonguay, S (ed.); Geological Survey of Canada, Open File 8712, 2020 p. 93-107, https://doi.org/10.4095/323668 Open Access|
|Publisher||Natural Resources Canada|
|Related||This publication is contained in Targeted Geoscience
Initiative 5: contributions to the understanding of Canadian gold systems |
|Lat/Long WENS|| -79.0000 -78.7500 49.8833 49.7167|
|Subjects||economic geology; tectonics; stratigraphy; structural geology; geochronology; geochemistry; Nature and Environment; Science and Technology; Archean; mineral deposits; base metals; precious metals; gold;
zinc; silver; copper; volcanogenic deposits; sulphide deposits; ore mineral genesis; mineralization; ore controls; structural controls; mineral exploration; exploration guidelines; host rocks; bedrock geology; structural features; faults; shear
zones; lithology; igneous rocks; intrusive rocks; felsic intrusive rocks; gabbros; volcanic rocks; andesites; dacites; rhyolites; lava flows; felsic volcanic rocks; mafic volcanic rocks; basalts; tuffs; volcano-sedimentary strata; sedimentary rocks;
argillites; mafic rocks; iron formations; tectonic evolution; tectonic setting; magmatism; volcanism; intrusions; sills; domes; dykes; lenses; hydrothermal systems; deformation; mineral enrichment; alteration; sedimentation; stratigraphic analyses;
geochemical analyses; radiometric dating; uranium lead dating; zircon dates; mass spectrometer analysis; geometric analyses; Abitibi Greenstone Belt; Harricana-Turgeon Belt; B26 Property; Brouillan Volcanic Complex; Brouillan Group; Enjalran-Bapst
Group; Selbaie Deposit; Brouillan Pluton; Precambrian|
|Illustrations||location maps; geoscientific sketch maps; cross-sections; tables; plots; photographs; Concordia diagrams; schematic cross-sections|
|Program||Targeted Geoscience Initiative (TGI-5) Gold ore systems|
|Released||2020 06 11|
|Abstract||Archean synvolcanic base metal deposits vary greatly in style and metal budget through time and space. This variability is due to contrasting geological and magmatic settings, the influence of which
remains a research topic with potential exploration implications. The B26 Cu-Zn-Ag-Au project, located in the Harricana-Turgeon belt of the northern Abitibi greenstone belt, is interpreted as a volcanogenic massive sulphide deposit formed in an
evolving calc-alkaline (FII-type) intermediate to felsic centre (Brouillan volcanic complex). The B26 deposit is enriched in Ag and is part of a group of precious metal-enriched Archean volcanogenic massive sulphide deposits that are associated with
calc-alkaline volcanic rocks, indicating that such successions are highly prospective.|
The B26 host succession, informally divided into a lower intermediate member and an upper felsic member, is composed of an andesitic base intercalated with
dacitic domes, onto which the felsic member was emplaced. The felsic member comprises three geochemically and texturally distinct rhyolite units that were emplaced as sills, domes, and/or flows with associated relatively voluminous fragmental facies.
This felsic succession, dated at 2728 Ma, is coeval both with the host rhyolite of the nearby Selbaie polymetallic deposit and the Brouillan pluton. It is overlain by thin sedimentary strata and cut by andesitic sills and andesitic transposed dykes.
This volcanic pile, undergoing extension and containing thick permeable strata, was favourable for the development of a high-temperature hydrothermal system characterized by extensive zones of Cu-rich stringers and sub-seafloor Zn-Ag-(Pb)-rich
sulphide lenses in an evolving, possibly shallow-water, active volcanic centre.
|Summary||(Plain Language Summary, not published)|
The main objective of phase 5 (2015-2020) of Natural Resources Canada and Geological Survey of Canada's Targeted Geoscientific Initiative (TGI) program
was to generate new knowledge, methodologies and models to enhance the exploration industry's ability to detect buried ore deposits. This synthesis volume contains 20 individual papers that discuss craton to deposit-scale characteristics of
auriferous deposits, plus some support material pertaining to the TGI-5 Gold project.