Distribution of Platinum-Group Elements in the Ebay claim, central part of the Bell River Complex, Matagami, Quebec.

摘要

The Bell River Complex (BRC) is a mafic layered complex located 30 kilometers southeast of Matagami in northern Abitibi. The complex is divided into three parts: The East, the Central and the West. The Central part of the intrusion contains the Platinum Group Elements (PGE) occurrences Bwest, Dotcom and Ebay.;The BRC is visibly and polymetamorphosed with regional metamorphism reaching greenschist to amphibolite facies (Goutier, 2005) and contact metamorphism at albite-epidote hornfels facies and in few places to hornblende hornfels facies.;A series of boreholes made by Hinterland were used to reconstruct the BRC stratigraphic sequence in the area of Ebay. A total of 65 samples were taken from 28 boreholes at Ebay for detailed analyses of petrology and geochemistry.;The analyses show that there is a concentration of PGE values that can reach 1-2 g/tonne Pt+Pd, with Pt/Pd ∼ 1. Many of these high values are found at the top of a melanocratic layer and therefore the presence of a reef is proposed. Disseminated sulphides are present, however the PGE are not associated with them. The PGE are present as PGM mainly bismuth-tellurides and arsenides of Pt and Pd.;This project is focused on the Ebay claim (property of Hinterland Metals Inc.) which is centered on the Elizabeth Bay and Opaoca River. The BRC around Ebay consists of layers of leucocratic and melanocratic metagabbros that are folded with an orientation that is predominantly E-W and dipping south 70-80 degrees. The leucocratic layers consist of a sequence of meta-leucogabbronorites, meta-leucogabbros, meta-leucotroctolites and meta-anorthosites. The melanocratic layers consist of a sequence of meta-melanogabbros, meta-olivine-gabbronorites, meta-gabbronorites and meta-pyroxenites. The layered mafic complex is crosscut by sills, dykes and quartz veins associated with the Opaoca and Olga granitic plutons.;It is suggested that in the magmatic chamber a sulphide liquid collected Ni, Cu and PGE. Then gravity settling gathered together all of the sulphide droplets in a layer. Some time later during metamorphism Sand Cu were mobilized, but left the PGE as PGM phases.