Abstract

Mapping of regolith is significant to identify and discriminate geomorphic expression, regolith evolution, weathering histories and assistance in clarification of relationships between parent and surface materials. In this research work, the hydrothermally altered regolith of Western Jahajpur Belt, Bhilwara, India is studied using ASTER and AVIRIS imageries by PCA, decorrelation stretching supervised classification image processing methods. Results of decorrelation stretching of ASTER spectral bands 6, 7 and 9 showed the regolith in blue, green and red colour with the associated geological formations. Analyses of VNIR-SWIR spectral bands of ASTER by PCA showed the bed rocks associated to the regolith green, yellow, white and red colours, respectively. The minerals of the regolith and parent geological formations are identified using AVIRIS data by supervised classification and endmember spectral analyses. The study also identified six regolith-landforms which include the regolith (vegetation cover), crop land (vegetation cover), water, crop land with vegetation, alluvium and regolith (ferruginous and calcareous mineral zone). The discrimination of regoliths and geological formations are verified in the field and confirmed by XRF and ICP-MS geochemical analysis of samples.

摘要

风化层的测绘对于识别和区分地貌表现、风化层演化、风化历史以及帮助澄清母体和地表材料之间的关系具有重要意义。在这项研究工作中，印度 Bhilwara 西部贾哈杰普尔带的热液蚀变风化层使用 PCA 的 ASTER 和 AVIRIS 图像进行了研究，该方法是去相关拉伸监督分类图像处理方法。ASTER 光谱带 6、7 和 9 的去相关拉伸结果显示了蓝色、绿色和红色的风化层以及相关的地质构造。PCA 对 ASTER 的 VNIR-SWIR 光谱带的分析显示，基岩分别与风化层绿色、黄色、白色和红色相关。通过监督分类和端元光谱分析，使用 AVIRIS 数据识别风化层和母体地质构造的矿物。该研究还确定了六种风化层地貌，包括风化层（植被覆盖）、农田（植被覆盖）、水、有植被的农田、冲积层和风化层（铁质和钙质矿区）。风化层和地质构造的鉴别在现场得到验证，并通过样品的 XRF 和 ICP-MS 地球化学分析得到证实。