ASTER Remote Sensing Image-Based Lithologic Information Extraction Of The East Kulun Orogenic Belt

Rock spectral features is the foundation of using remote sensing methods to identify lithology, The rapid development of remote sensing technology promoted the research on rock spectral features on and rock spectroscopy, the latter prompted remote sensing lithology recognition technology further development.This article selects Hot Springs Reservoir area in the east Kunlun orogenic belt of Qinghai-Tibet plateau as the research object, using remote sensing data ASTER studying the lithologic information extraction of this area, through the analysis of the typical lithology spectral features, using principal component analytical method, mineral index method, obtaining the following results:(1) This paper is intended to make a study of the spectral characteristics comparision for different lithology , through analysizing the spectrum characteristic of limestone, sandstone, slate and combining with the chemical composition analysis of the rock samples. The results show that the limestone which main composition is CaO, its spectrum characteristics is mainly cause by the CO32- groups vibration, the emission spectrum characteristics of sandstone which main component is SiO2 is mainly caused by Si-O bond vibration .(2) Based on the processing of the ASTER remote sensing image with the method of principal component analytical , compare the principal component analysis image with the traditional image , the results show that tonal and texture of the PCA image is more clearer and the anomalies "S" shape altered strip in north of Xueshui River is prominent.(3) The mineral index image, which is converted from ASTER image by analyzing the mineral index in the study area, can reflect the distribution of different kinds of minerals. The boundaries of the carbonatite, slate and volcanic rocks can be distinguished on a color composite mineral index image.(4) The rocks in the study area can be classified into five units according to the field observation and the measured sections: Limeston-dolomite, sand stone-conglomerate-slate, conglomerate and basalt - volcanic rocks and loose deposits. An interpretation key of each rock unit is established by studying the image features, and a general lithological interpretation map and a lithological distribution map are then created based on this key.Comprehensive results above research show that ASTER data spectral resolution is high, providing minerals information fine, clear and rich. mineral index method used can very good extraction lithology and altered information, especially carbonate, partial base sex rock, altered rock recognition effect is more apparent, different lithology types of boundaries can be clear circle in remote sensing image, the lithology circle line is consistent with the lithology boundaries on-the-spot field geological survey found.