Hyperspectral reflectance spectrometry in the exploration for VMS deposits using the Izok Lake Zn-Cu-Pb-Ag deposit, Nunavut as a test site

Abstract

We have investigated the application of ground, laboratory and airborne optical remote sensing methods to the detection of hydrothermal alteration zones associated with volcanogenic massive sulphide (VMS) deposits using the Izok Lake Zn-Cu-Pb-Ag deposit, Nunavut as a test site. The deposit is located in a subarctic environment where lichens are abundant on the rock outcrops. The rhyolitic host rocks to the deposit have been hydrothermally altered and contain white mica and chlorite group minerals. These alteration minerals have Al-OH and Fe-OH absorption features in the short-wave infrared (SWIR) wavelength region. The absorption feature wavelength positions can shift as a function of chemical compositional changes within minerals. In and around the Izok Lake deposit there are systematic trends in the Al-OH and Fe-OH absorption feature wavelength positions with distance from the massive sulphide lenses. Furthermore, these trends can be detected in bulk rock lithogeochemical data. Our results demonstrate the feasibility of using hyperspectral remotely sensed data to delineate hydrothermal alteration zones and determine alteration intensity in high-latitude regions.