Petrochemistry of I-type magnetite-series granitoids of the northern Chile, Highland Valley, southern B. C., Canada, Erdenet mine, Mongolia, Dexing mine, China, Medet mine, Bulgaria, and Ani mine, Japan

Abstract

    Granitoids from porphyry copper mineralized regions from selected areas in the world were reexamined by the polarized X-ray method. The studied samples in Chile include regional collection of three transects, North, Central and South, including Chuquicamata, El Salvador, Rio Blanco-Los Blances and El Teniente mines. The east-west variation in younging the age toward east is best shown in the North and Central transects. Components that tend to increase toward the inner direction are Al₂O₃,Na₂O, P₂O₅ and Sr, while those of decreasing are Y, total Fe and V. The innermost is a zone of porphyry copper deposits. Therefore, high Sr/Y granitoids prevail in the innermost and youngest zone.