Magnetic modeling of the Candelaria IOCG deposit, Chile: the influence of remanent magnetism and self-demagnetisation

AUSTIN, J.; HILLAN, D.; GEUNA, S. E.; CLARK, D.A.

Lima

Conferencia; SEG (Society of Economic Geologists) Conference 2012; 2012

Forward modelling of magnetic data over magnetite-rich sources, such as Iron Oxide Copper-Gold deposits (IOCGs) is problematic and quantifying the effects of remanence and self-demagnetisation are critical. However, measurement of remanence is often neglected and its importance in IOCGs is poorly understood. In this study, we present analyses of remanent magnetisation from the Candelaria deposit, Chile and compare the results with Proterozoic magnetite-rich IOCGs of the Cloncurry district, Australia. We discuss how remanence can be contaminated by drilling, show that remanence is less important than self-demagnetisation for magnetite-rich IOCGs, and provide examples of difficulties encountered with modelling IOCGs