WALL ROCK ALTERATION IN THE NIPISSING DIABASS SILL COBALT, ONTARIO

Abstract

A petrographic description of the wall rock alteration bordering joints and veins in the “Tipissing diabase sill at Cobalt, Ontario; a comparison with Butto, Montana, and a proposed mechanism to account for tho observed alteration sequences. Illustrated with photographs, photomicrographs, and maps.