Detailed Study of a Porphyry Copper Deposit Using Airborne Imaging Spectroscopic Data

Porphyry copper deposits represent very large differentiated hydrothermal alteration footprints resulting from convective fluid circulation. Hyperspectral imaging spectroscopy can provide a rapid and effective tool for systematic mapping of mineralogical footprints of many mineral systems including the porphyry copper deposits at local to regional scales. To demonstrate the capability of airborne hyperspectral imagery in deposit scale exploration, a portion of the HyMap data collected over a porphyry copper deposit named Shadan in eastern Iran was selected. By using a combination of spectral unmixing techniques and feature extraction methods, a large suite of alteration minerals was detected over this deposit. This includes white mica abundance, composition, and crystallinity, kaolinite abundance and crystallinity, ferric oxide content and composition, together with jarosite, chlorite-epidote, amphiboles, and tourmaline abundances and distribution. The results of this study indicate that airborne hyperspectral imagery and their mineral map products can be used to delineate porphyry copper systems and target the most promising areas for further exploration activities.