Carrapateena: physical properties of a new iron-oxide copper-gold deposit

Abstract

Carrapateena is a new Olympic Dam - style, iron-oxide copper-gold (IOCG) deposit, located approximately 160 km north of Port Augusta and 100 km south-east of Olympic Dam, South Australia (Figure 1). Carrapateena was discovered in June 2005, when significant copper-gold mineralisation was intersected by RMG Services Pty. Ltd. (RMGS), within drill hole CAR002. CAR002 was targeted on near - coincident gravity and magnetic anomalies and ended in mineralised hematite breccia, returning an intercept of 178.2m at 1.83% Cu, 0.64g/t Au, 0.21% Ce, 0.13% La and 59ppm U, from 476m, including a high grade top of 73m at 2.89% Cu and 0.4g/t Au (Vella and Cawood, 2006). Following on from RMGS? success, subsequent exploration by joint venture partner, Teck Cominco Australia Pty. Ltd., (TCA) has demonstrated Carrapateena to have strong similarities with Olympic Dam, albeit at a smaller scale. It is now known that significant copper-gold mineralisation exists at Carrapateena (for example, drill hole CAR050 intersected 905m @ 2.1% Cu and 1g/t Au), but the overlying 470m thickness of moderately conductive Stuart Shelf sediments presents significant technical challenges to exploration. Therefore, a solid understanding of the physical properties of both cover sequence and basement rocks is critical. To this end, extensive laboratory petrophysical testing has been carried out on drill core samples, with measurements comprising mass properties, inductive properties, galvanic electrical measurements, natural remanent magnetisation and P-wave velocity. Electrical anisotropy of the cover sequences has also been investigated. The results of this work will be presented here, following a description of geological setting.