AbstractsEarth & Environmental Science

Note: p. 15 missing Since the discovery of the famous deposits of the Sudbury district, the surrounding area (part of the Temiskaming sub-province of the Canadian shield) has received considerable attention, including systematic and detailed geological mapping, and intensive prospecting throughout the district. In the geology of the area, three different problems are presented. These are: (1) the structural and time relationships of the norite - micropegmatite, the granites of the southern nickel range, the rock of the offsets; (2) the character of the noritend cropegmatite itself; (3) the genesis of the nickeliferous pyrrhotite ore bodies. In this paper the relationship of the norite and the quartz diorite of the Copper Cliff offset will be discussed. It is important to work out both the correct relationships and the age of the quartz diorite because, as all recent workers now agree, the sulfide ore bodies are genetically related to this rock. The quartz diorite is “offset rock”, so called by Coleman, (1903), because many of the dykes seemed to be extensions or offsets from the main norite mass. Evidence favouring the offset rocks as part of the norite has been set forth also by Burrows and Rickaby, (1934), and Collins (1934, P. 169). On the other hand, evidence for regarding the offset rocks as a separate and much later intrusion has been assembled by Yates (1938 ). Recent studies in the Sudbury area by Cooke, (1946, P. 69), led him to support Yates’ conclusions.[...]