Volcanological Reconstruction of the Corbet Breccia Pile, and Cu-Zn Massive Sulfide Deposit, Noranda, Quebec

Exploration & Mining Geology, Vol. 2, No. 1, 1993

H.L. GIBSON, Department of Geology, Laurentian University, Sudbury, Ontario, Canada, D.H. WATKINSON, Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada, J.J. WATKINS, LAC Minerals Limited, Vancouver, British Columbia, Canada, M. LABRIE and G. DOIRON Minnova Inc., Rouyn-Noranda, Quebec, Canada

The Corbet deposit is one of 17 proximal Cu-Zn massive sulfide deposits located within the Noranda Cauldron which occurs within the core of the Noranda Volcanic Complex. The deposit is located at the top of the Flavrian Formation, the lowermost formation of the 3000 m thick Mine Sequence; the deposit has yielded 2.75 M tonnes of ore grading 3% Cu, 0.96% Zn, 2.06 g/t Ag and 1.0 g/t Au. The multi-lens Corbet deposit formed within a 250 m wide crater that occurs within a localized breccia pile. The Corbet breccia pile was constructed by explosive magmatic and hydrovolcanic eruptions localized along the south flank of a larger andesitic shield volcano that formed during the waning stages of Flavrian volcanism. The breccia footwall of the deposit allowed unfocused and widespread hydrothermal discharge that resulted in the development of a large area of chlorite and fringing sericite alteration that exceeds, by six times, the size of the sulfide lenses and represents a significant exploration target.