Quaternary geology of the Buchans area, Newfoundland: implications for mineral exploration
Mineral exploration for volcanogenic massive sulphide deposits in the Buchans area of central Newfoundland is hindered by thick and widespread Quaternary overburden comprising glacial, glaciolacustrine, glaciofluvial, and resedimented deposits. Mapping of striations and indicator erratics suggests that the area was affected by four ice-flow events: I, southward; II, northeastward and westward to southwestward; III, southward; and IV, northeastward and southwestward. Vertical and areal distributions of lead, copper, and zinc indicate that till and glaciolacustrine sediments overlying sulphide deposits can be enriched in mineralized debris. Near mines at Buchans surficial debris-flow deposits contain much material derived from the Topsails igneous terrane and are generally impoverished in mineralized debris. Southwest of Buchans, however, they can be enriched. Mineral exploration in the Buchans area must take into account that (i) sulphide-rich debris in till does not reflect only the youngest ice-flow even...