Petrogenesis of mineralized horizons in the Offset and Creek zones, Lac des Iles Complex, N. Ontario

Abstract

The Lac des Iles Complex is a Neoarchean polyphase mafic-ultramafic complex located in the Marmion terrane of the Superior Province, 85 km north of Thunder Bay, Ontario, Canada.

The intrusive complex can be subdivided into two discrete subcomplexes: the ultramafic- dominated North Lac des Iles Complex and the mafic-dominated South Lac des Iles Complex

(SLDIC). The SLDIC has been subdivided into the gabbronorite, breccia, norite, and diorite domains. To date, economic Pd-rich mineralization has been discovered in both the breccia and norite domains and occurs proximal to the contacts between the breccia and gabbronorite domains and between the breccia and norite domains. The objectives of this study were to i) evaluate the mechanisms of formation of the mineralized horizons near the contact between the breccia and norite domains in the Offset and Creek zones of the SLDIC, and ii) assess the tectonic setting in which the SLDIC formed. [...]