The Geoscan Airborne Multispectral Scanner as an exploration tool applied to El Halcón prospect, Chile

Abstract

The Geoscan Airborne Multispectral Scanner (AMSS) is a narrow band remote sensing device which can record up to 24 channels from 46 available spectral bands within the range of 0.49 microns to 12.0 microns. These spectral bands comprise 10 in the visible/near infrared (VNIR), 8 in the shortwave infrared (SWIR) and 6 in the thermal infrared (TIR) portions of the electromagnetic spectrum.

The remotely sensed data are processed by the Geoscan developed Geoscan Image Processing System (GIPSy). This system facilitates rapid manipulation and interpretation of the data. Of particular value as an exploration tool is the ability of the system to aid the user in the discrimination of contrasting rock types and alteration styles by using multi-band treatments.

This paper describes this system as applied to the El Halcon Prospect, near Copiapó, Chile, where it has aided the delineation of hydrothermal alteration zones. The known alteration comprises propylitic, argillic and sericitic zones plus areas of silicification. The presence of adjacent low grade copper mineralisation at depth has been confirmed and economic Cu and Au mineralisation is present at the periphery of the alteration zone. The prospect is interpreted as having significant potential to host a substantial porphyry copper deposit.