Geochemical prospecting for copper, West Otago

Abstract

Results of geochemical prospecting surveys for copper in the Moke 'Creek area, the Shotover district, and the Skippers Creek area of west Otago are presented. Copper in soils was found to be contained almost entirely within the finest fractions, and to be associated mainly with clastic chlorite. Anomalies in soils indicate that the cupriferous sulphide laminae of the Moke Creek Copper Lode extend beneath the soil at least 500 ft southward from the most southerly prospect pits, but the lack of anomalies to the north indicates that the copper lode does not extend much beyond Moke Creek. The source rocks of a cupriferous boulder found in the Shotover River may be a greenschist band in Ironstone Creek, with which are associated soil and water anomalies. Additional anomalies were found during a reconnaissance hydrochemical survey of the upper Shotover drainage system. The absence of strong geochemical anomalies in the Skippers Creek area suggests that cupriferous schist at Skippers Point does not extend into that area.