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Mines

Wednesday, November 23, 2022 – afternoon

Session 4 : Geoscientific knowledge acquisition work by the MERN and its university partners – Abitibi and Pontiac subprovinces

Chair and session organizer

François Leclerc

MERN

Co-chair

Hugo Dubé-Loubert

MERN

This session will be offered in French.

Abstract: Géologie Québec unveils the preliminary results of its most recent geoscientific knowledge acquisition surveys. The Bulletins géologiQUEs with novel interpretations, new mineralization zones and prospective exploration elements will be presented for the geological surveys of the Ungava orogen (Amarurtuuq), James Bay (Cadet Lake, Marée Lake), Abitibi (Alouettes Lake, Dickson Lake) and Grenville (Bellemare, Fourche Lake, Île-du-Grand-Calumet). New geochemical data from lake bottom sediments in the Eastmain River area will be discussed.

1:30 p.m.

Welcome from the chair

1:35 p.m.

Geology of the La Trêve Lake area, Abitibi Subprovince, Eeyou Istchee James Bay

Conference details

Authors: Yannick Daoudene (MERN) and Mélanie Beaudette (MERN)

This preliminary geological survey of the La Trêve Lake area (sheets 32G13-NE and 32J04-SE) refines the stratigraphy of this area. The volcanic and sedimentary rock package in the southern half of the map begins with the Roy Group. This group consists mainly of pillow and massive basalts belonging to the Obatogamau and Bruneau formations and gabbro sills. It also contains assemblages of felsic and intermediate volcanic and sedimentary rocks newly assigned to the Waconichi and Blondeau formations; the former locally bounds the Obatogamau and Bruneau formations, while the latter marks the top of the Roy Group. The overlying Opémisca Group exposes mainly detrital sedimentary rocks. At the base of the Opémisca Group, the La Trêve Formation has polygenic conglomerate and sandstone interbeds. At the top, the Daubrée Formation consists of sandstone beds including arenite, wacke and mudstone. Most polarities measured in the Roy and Opémisca groups indicate stratigraphic highs to the SE. Kilometric and rounded plutons of little to undeformed syenite and granite cut the volcano-sedimentary package. Although the rocks generally exhibit greenschist facies metamorphism, they show typical amphibolite-facies mineralogical assemblages at the margins of the plutons, even evidence of partial melting. NE-SW oriented dykes of decametric thickness and kilometric extension, composed of gabbro and gabbronorite, cut all the units described above. From a metallogenic point of view, several prospective geological environments deserve to be highlighted: i) the volcaniclastic rocks of the Blondeau and Waconichi formations for base and precious metals associated with VMS deposits; ii) the gabbro of one of the Abitibi Dykes and of the Mildred Stock margin for magmatic Ni-Cu (± PGE) mineralization; iii) the Saussure Stock syenite for Au and REE mineralization.

1:55 p.m.

Geology of the Alouettes Lake area, Abitibi Subprovince, Eeyou Istchee James Bay

Conference details

Authors: Yannick Daoudene (MERN) and Mélanie Beaudette (MERN)

2:15 p.m.

Geology of the Dickson Lake area, Abitibi Subprovince, Eeyou Istchee James Bay

Conference details

Authors: Antoine Brochu (MERN) and Maxym-Karl Hamel-Hébert (MERN)

2:35 p.m.

Volcanic rocks of the Blake River Group: geochemistry, petrogenesis and relationship to VMS deposits

Conference details

Authors: Octavio Vite-Sanchez (INRS-ETE), Pierre-Simon Ross (INRS-ETE) and Patrick Mercier-Langevin (GSC)

2:55 p.m.

Plutons of the Pontiac Subprovince

Antoine Godet

Université Laval

Conference details

Author: Antoine Godet (U. Laval)

3:15 p.m.

Metamorphic fluid generation in the Pontiac Subprovince (Superior Craton, Canada) and implications for orogenic gold mineralization

Isaac Siles Malta

Université Laval

Conference details

Author: Isaac Siles Malta (U. Laval)

3:35 p.m.

Gold Fluid Window project

Carl Guilmette

Université Laval

Conference details

Author: Carl Guilmette (U. Laval)