Thermal infrared spectra and TIMS imagery features of sedimentary rocks in the Kalpin Uplift, Tarim Basin, China

Abstract

Airborne Thermal Infrared Multispectral Scanner (TIMS) data and laboratory thermal infrared emission spectra were colleted for sedimentary rocks from the Kalpin Uplift, the northwestern margin of Tarim Basin. Sandstone, siltstone and argillite have low emissivity bands between 8 and 10 μm, which results from interatomic stretching vibrations of silicon and oxygen bound in the crystal lattice, and the position of band center has been shown to migrate towards longer wavelength with decreasing of quartz content and the variation of silicon‐oxygen structure. Carbonate rocks exhibit a low emissivity band near 11. 3 μm due to C‐0 bending modes, the position of band center moves to shorter wavelength as of Mg²⁺ content increases. Based on the analysis of thermal infrared spectral features of sedimentary rocks, integrated with results of the chemical analysis, X‐ray diffraction and thin‐section identification of sedimentary rocks, a colour composite of three of the seven channels of TIMS data was processed with a decorrelation stretch. The sandstones, siltstones, argillites, carbonate rocks and the transitional type rocks among them could be distinguished.