Genesis of Canadian massive Sulphides Reconsidered by Comparison to Cyprus Deposits

CIM Bulletin, 1965

R. W . Hutchinson Associate Professor, Dept. of Geology, University of Western Ontario, London, Ont.

Cupreous pyrite deposits in Cyprus have many geologic similarities to Canadian massive sulphide copper-zinc ores as well as certain significant differences. A comparison of the Cyprus and Canadian deposits indicates a complex genetic history for the latter and suggests that their origin should be re-examined. The Cyprus ores occur in subaqueous extrusive rocks near and at the top of a Cretaceous volcanic pile or igneous complex. The rocks have not been deformed, nor have they been deeply buried or deeply eroded. Apparently the ores formed near or at surface in the top of the volcanic pile by a volcanic-exhalative process and from an ore-fluid of volcanic derivation. The Canadian deposits are of comparable composition and have similar geologic settings, but occur in the most ancient Precambrian rocks. Their enclosing Keewatin greenstones have, in most places, been deformed, regionally metamorphosed and invaded by granitic intrusions.
Keywords: Canadian, chalcopyrite, Cyprus, Pillow Lavas, sphalerite, Deposits, Ore, Ores, pyrite, sulphide, Sulphides