Identification of hydrocarbon micro-seeps based on mineral alteration in a part of Cauvery Basin, South India using Hyperion Data

Abstract

Spectral analysis methods were applied for identification of altered minerals by matching the unknown spectra of the purest pixels with the pre-defined (Library) spectra. Three methods, namely Spectral Feature Fitting (SFF), Spectral Angle Mapper (SAM) and Binary Encoding (BE) were used to produce a score between 0 and 1, where the value of 1 equals a perfect match showing the exact mineral type. Four possible altered minerals namely alunite, kaolinite, calcite and siderite were identified based on different scores related to their abundance in the soils. Spectral Feature Fitting (SFF) technique was also used to classify the minerals in the satellite imageries. Based on the spectral analysis and mineral alteration characteristics, the possible hydrocarbon micro seep zones were identified in the Nagapattinam sub-basin of Cauvery Basin, Tamilnadu, India.