Lithological mapping on the Antarctic Peninsula using advanced spaceborne thermal emission and reflection radiometer (ASTER) data

The Antarctic Peninsula is larger than the UK and with limited geological mapping campaigns since the 1940s significant gaps in coverage remain, particularly in areas where access is difficult. Remote sensing offers potential for improving geological mapping on the peninsula but has not been used for these purposes. This thesis describes the use of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for lithological mapping of predominantly calc-alkaline subduction-related igneous rocks on the Antarctic Peninsula. The research encompassed lithological mapping of four study areas selected to provide an appropriate test of the potential of ASTER. Processing of ASTER reflectance and thermal emission data used spectral enhancement procedures and the matched filter (MF) spectral mapping method. This was supported by reflectance spectroscopy of rock samples, Hyperion data, thin section petrography, geochemical data for acid volcanic rocks, and fieldwork on Adelaide Island. The research shows although outcrop is limited in the polar context, weathering effects and vegetation cover do not cause significant problems. ASTER provides a range of lithologic information enabling validation of inferred field mapping and new observations of unmapped geology in the study areas. Granitoids and silicic volcanic rocks display distinctive spectral properties and are newly identified from unmapped parts of the Oscar II, Foyn, and Lassiter coasts. Areas of localised alteration in these rocks are readily discriminated based on the distinctive absorption features of the alteration mineral assemblages. ASTER is less successful at discriminating intermediate-mafic igneous, sedimentary and metamorphic lithologies that display more ambiguous spectral features. For these rocks lithological mapping is strongly reliant on existing field observations to resolve ambigious results. The research shows that although ASTER is limited in its ability to uniquely discriminate different rock types it can provide important lithological information in support of geological mapping on the Antarctic Peninsula