Research On Remote Sensing Geological Interpretation And Altered Information Extraction Of Bauxite In Guizhou Longxing-Dazhuyuan Region

Longxing-Dazhuyuan region is located in Dalou and Wuling mountains of branching interchange of Southeastern Guizhou, where is shrouded by warm climate and very rich in bauxite resources. Local bauxite has one type named weathering crust sedimentary bauxite. Geological structure condition, lithology formation condition and other factors constitute a metallogenic conditions. Based on remote sensing technology and Landsat8-OLI multi-spectrum data and Pleiades high-resolution data, this article conducted a geological interpretation. With the usage of remote sensing interpretation signs, bauxite-bearing strata and roof-floor strata was found. Being due to the rich hydroxyl ions in bauxite, bauxite exception information can be extracted, the abnormal area and terrain-geologic map was overlaid and analyzed. Then according to the geological background and metallogenic regularity of the study area, pointing out several prospect-areas. This thesis mainly achieves the following results.1. The information is collected mainly about traffic location maps, terrain-geologic maps, multispectral remote sensing data in high and low resolution. Relevant literature and reports are checked out mainly about remote sensing fold interpretation, fault interpretation, lithologic interpretation, alteration information extraction in high vegetation coverage area, metallogenic prediction and bauxite distribution characteristics of each region in Guizhou Province.2. Through image preprocessing such as atmospheric correction, geometric correction, cropping and image enhancement processing like ratio enhancement, contrast enhancement and principal component analysis,1:100,000 geological interpretation had been conducted in this research area. With the usage of remote sensing interpretation signs, five fold structures and four groups nearly NE-NNE, SN, NW and EW trending faults were found, and the spatial distribution and image features of rock lithology had been defined. These interpretation results would be significant to analysis the geological conditions of this region.3. Because of the closed association between hydroxyl abnormalities and bauxite mineralization bauxite exception can be indirectly extracted by extracting the hydroxyl abnormalities. In this article, method " Band Ratioing+Principal Component Analysis " and method "masking+Crosta" had been applied to hydroxylation alteration respectively in vegetation coverage area. Referred to the bauxite deposits data, compared and analyzed the feasibility of the two methods.4. According to the structure and lithology metallogenic conditions, using the distribution of the mineralization area and the geological interpretation results such as faults, fold structure and lithology information, classified in favorable mineralization region. We can obtain two favorable metallogenic areas at level A, two favorable metallogenic areas at level B and four favorable metallogenic areas at level C.