Gold exploration using tills of the Beardmore-Geraldton area, northern Ontario

CIM Bulletin, Vol. 82, No. 922, 1989

Stephen R. Hicock, The University of Western Ontario, and Fridrik J. Kristjansson, Ontario Geological Survey

Three varieties of till are recognized in the Beardmore-Geraldton area: local lodgement till, nonlocal carbonate till, and local supraglacial till. The local lodgement till unit is examined in detail for the first time in this paper. It is the best potential overburden exploration medium for gold and other metals because its particles were locally-derived and deposited sub-glacially, probably within a few kilometres downglacier (south-westward) from their sources, and have not been diluted by distantly-derived glacial debris. Both local tills are richer in gold and other metals, relative to nonlocal carbonate till. Local lodgement till rests on bedrock and was encountered frequently at or near the surface in thin drift/bedrock terrain (a widespread terrain type within the west half of the study area), and commonly at the base of boreholes in thick till terrain.

Mots Clés: Exploration Geology Beardmore-Geraldton area, Gold Exploration, Till