Rock type mapping with indices defined for multispectral thermal infrared ASTER data: case studies

ASTER sensor aboard NASA's Terra satellite has the capability of measuring multispectral thermal infrared (TIR) emission from the earth's surface to space. The author proposed indices by the combination of ASTER-TIR bands for detecting quartz and carbonate minerals, and another index to estimate the abundance of bulk SiO₂ content in the surface silicate rocks, applied them to the low level ASTER radiance at the sensor data without atmospheric corrections, and showed a potential ability of the indices in a rock type mapping. This paper tries to apply the proposed method into the practical case studies using ASTER-TIR data. The study sites include ophiolitic belt zones in Oman and along Yarlun Zangbo River in Tibet. The applied results are compared with the geology of the study areas. It indicates that the new remote sensing approach proposed here would improve the quality and the cost of the geological mapping in arid and semi-arid regions.