Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)can provide high quality of multispectral data for detecting lithology. This study attempted to extract lithlogical and mineralogical information in the arid region using the ASTER multispectral data. Based on the analysis of chemical composition，mineral composition and the spectral absorption characteristics of different lithostratigraphic units，the Relative Absorption BandDepth(RBD)and the bandsratio method were adopted to process ASTER VisibleNear Infrared(VNIR)and ShortwaveInfrared(SWIR)multispectral data from the east Kalpin Uplift，southwest Tian Shan. Limestone，dolomite，sandstone，blueschist/greenschist and psammitic schist/pelitic schist，in the study area were well discriminated. The absorption spectrum center wavelength of dolomite is near 232 μm is shorter than 235 μm of limestone，and thus RBD7 and RBD8 can be employed effectively to identify dolomite and limestone，respectively. Felsic rocks show AlOH and Fe3+ absorption characteristics in the VNIRSWIR region，while the maficultramafic rocks show Fe2+ and Fe，MgOH absorption features，hence the use of different valence state of iron and secondary minerals can distinguish them：ASTER band2/band1 represent Fe3+ distribution，ASTER band2/band1 represent the Fe2+ distribution，RBD6 can estimate the AlOH mineral abundance. Psammitic/pelitic schist containing phengite，chlorite，stilpnomelane，as well as the weathered surface covered by clay minerals，exist characteristic absorption spectrum in the 221 μm(band 6)，and has a high reflectance in 165 μm(band 4)，while the blueschist/greenschist show high reflectance in the 221 μm(band 6)，and it exit low reflectance in 165 μm(band 4)，and blueschist/greenschist appear low ASTER band4/band6 ratio. Therefore，the band ratio of ASTER band 4 and band 6 can effectively distinguish blueschist/greenschist and psammitic/pelitic schist.
. Detecting lithologic features from ASTER VNIRSWIR
multispectral data in the arid region：
A case study in the eastern Kalpin uplift|
southwest Tian Shan
[J]. Chinese Journal of Geology, 2010, 45(01): 333-347.