Field Relations of Matagami Sulphide Masses Bea ring on their Disposition In Time and Space

CIM Bulletin, 1965

Masses of pyritic copper and zinc ores are entrapped along the contact zone between two volcanic groups in the matagami area. The upper limits of the sulphide concentrations tend to form concordant contacts against lava or cherty tuffite units of the younger group; the lower extremities tend to either follow transverse structures or merge with zones of dispersed sulphides. The sulphides are deformed and intruded by folded dykes. Close relations between metallization boundaries and volcanic lithology and stratigraphy, and a preliminary investigation of the fabrics and crystallization temperature of the sulphide masses, suggest that the copper and zinc (but ;not necessarily all the iron sulphides) were emplaced at h1gh temperatures during volcanism in near-surface lithological-stratigraphic traps.

Keywords: Deposits, gabbro, pyrite, schist, sphalerite, volcanic belt, Rock, Rocks, Structure, sulphide, Sulphides, Volcanic, Volcanics