Caractéristiques, chronologie et typologie des minéralisations aurifères de la région du Lac Shortt (Québec), sous-province archéenne de l'Abitibi /

Abstract

IVJe dédie cette thèse à mes parents qui m'ont insufflé le goût du dépassement et du travail accompli. Je suis tout particulièrement redevable envers ma conjointe Marie-Claude qui m'a accordé sa compréhension et son soutien durant toute la durée de cette étude et qui en plus a révisé le texte pour en assurer la qualité linguistique. VI

Archean Sanukitoid Gold Porphyry Deposits: A New Understanding and Genetic Model from the Lac Bachelor Gold Deposit, Abitibi, Canada

“…In this evolution model, the Opawica-Guercheville deformation zone may be an early ductile dextral shear zone that was reactivated under brittle-ductile conditions. Vertical movement of this steeply dipping shear zone was also observed in the field (Daigneault, 1996;Brisson, 1998).…”

“…These late-to posttectonic stocks have a monzonite to syenite composition and are often associated with lamprophyres and locally with carbonatites (e.g., Lac Shortt, Nadeau et al, 2014). The Lac Bachelor gold deposit is located at the edges of the late-to posttectonic O'Brien syenite stock complex (Graham, 1957;Buro, 1984;Morasse, 1988;Lauzière, 1989;Prud'homme, 1990;Brisson, 1998;Fayol et al, 2013;Nadeau et al, 2014) that intrudes the andesites and volcaniclastic rocks of the Obatogamau Formation.…”

“…The deposit is located in the northeastern part of the Abitibi subprovince, near the intersection between a major and unusual northeast-southwest structure, the Wedding-Lamarck deformation corridor and the east-west Opawica-Guercheville fault (Graham, 1957;Buro, 1984;Lauzière, 1989), which is also host to the Lac Shortt deposit ( Fig. 1; Morasse, 1988;Prud'homme, 1990;Brisson, 1998;Nadeau et al, 2014). The deposit was reopened in 2011 by Metanor Resources Inc. after a successful exploration campaign that evaluated the Lac Bachelor gold resources at 6,558 kg (210,857 oz).…”

The Archean magmatic-hydrothermal system of Lac Shortt (Au-REE), Abitibi, Canada: Insights from carbonate fingerprinting

“…These deposits are often found in close association with post-orogenic Timiskaming-type conglomerates and are of Timiskaming age (2680( -2672. The genesis of this class of deposit remains obscure and the present paper aimed at deciphering the origin of such mineralization by studying the Lac Shortt deposit, near Lebel-sur-Quévillon (Morasse, 1988;Prud'homme, 1990;See, 1994;Tilton and Bell, 1994;Brisson, 1998;Nadeau et al, 2012).…”

“…The Lac Shortt Au-REE deposit hosted 2.7 Mt of ore at an average of 4.6 g/t Au (total 12.4 tons Au; Brisson, 1998). The mineralization was associated with a complex suite of intrusions consisting of alkali gabbros, syenite, carbonatite and silicocarbonatite plugs and dykes, undifferentiated mafic and dioritic sills, and ultramafic, calc-alkaline and alkaline lamprophyres (Morasse, 1988;Prud'homme, 1990;Bourne and Bosse, 1991;See, 1994).…”