Landsat ETM+ Imaging for the Exploration of Epithermal Deposits in the Azuero Peninsula (Panama)

Remote sensing can be understood as the science, technology and art of acquiring, processing, and interpreting airborne or spaceborne images that record the interaction between matter and electromagnetic energy (Sabins, 1997, Aranoff, 2005). Nowadays a plethora of satellites surrounding the earth provides continuous sets of data of quite different nature used for navigation, positioning, meteorology, surface temperature, sea water condition, etc. Among the most interesting satellites dedicated to systematically provide global covered of earth resources are the Landsat family. The currently operative Landsat sensors (Thematic Mapper “TM” and Enhanced Thematic Mapper “ETM+”) record three wavelengths intervals (bands) of visible energy (blue, green, and red) plus four inferred bands, including a thermal one. Such broad spectral coverage together with their mid-range spectral and spatial resolution allows the identification and analysis of the vast majority of surface materials, including rocks, soils, vegetation, snow and/or ice, and manmade materials (Crosta and de Souza, 2009). In geologic terms Landsat provides data especially useful for mineral exploration. It can be used to identify areas containing minerals useful in the search for mineral deposits, including iron oxides and/or hydroxides (hematite, goethite and limonite), clays (kaolinite, dickite and montmorillonite), micas (illite, sericite and muscovite), sulfates (jarosite and alunite) and carbonates (calcite and dolomite). The aim of the present work is to use Landsat imagery for reproducing the hydrothermal alteration system of a well-studied mineralized area, such us the Cerro Quema epithermal Au-Cu deposit, in order to apply an additional exploration criterion in similar terrains. Here we present the preliminary results of this research.