Sub-pixel Mineral Mapping of Serpentine and Magnesite for Chromite Exploration, Using Hyperion (EO1) Images

Abstract

Abdasht chromite mine is located in the ultramafic complex of southern Iran, which has abundant chromite reserves such as Soghan, Esfandagheh, Faryab, etc. The main purpose of this study was to investigate the capability of Hyperion in the alteration mapping related to chromite mineralization in the Abdasht area, south of Kerman Provine, Iran. Since serpentine and magnesite have been observed associated with chromite in this area, mapping of these minerals can be used for the exploration of chromite. For this purpose, atmospheric correction/calibration was performed on the Hyperion images. The representative samples collected from the outcrops in the area were tested in the laboratory of the Iranian Space Agency and the spectra of serpentine and magnesite were extracted. Serpentine and magnesite were mapped, using Spectral Angle Mapper (SAM) and Matched Filtering (MF) methods. In order to verify and control the results, a field visit has been made to the area. The obtained classification accuracy for serpentine obtained from MF and SAM methods were 87% and 81%, respectively. Magnesite map showed an overall accuracy of 65% and 60% for MF and SAM methods, respectively. The lower accuracy of magnesite can be attributed to its small extent in the field. It is suggested that due to the power of Hyperion images in the detection of chromite-bearing serpentine rocks, these images can be used for the exploration of chromite.

Keywords

• remote sensing
• hyperion
• chromite
• alteration
• serpentine
• magnesium