ON GENETIC MODEL OF DONGCHUAN TYPE STRATA-BOUND COPPER DEPOSIT

Abstract

Dongchuan type strata-bound copper deposit includes the stratiform copper deposits and the veined copper deposits in the Kunyang Group. Stratiform copper deposits occurred in different cycles and definite facies of the cupreous algal reef carbonate formations precipitated in the Kangdian Pre-cambrian geosyncline in the middle stage of its development. The ore-forming conditions are essentially the source bed, algal reef and the ore trapping bed. The mineralization proceeded throughout the whole sedimentary process, in which reef building and diagenesis played an important part. The mechanism of the formation of the stratiform copper deposits is tentatively referred to as "red bed-derived and algae-bound diagenesis-metallogenesis model". In the final stage of the development of geosyncline, the copper would be removed from the pre-existing stratiform copper deposits to be precipitated in some favourable beds to form a veined ore shoot or a veined copper deposit during the teetonie movement and the accompanying volcanism and metamorphism.