Study On Hyperspectral Remote Sensing Alteration Characteristics Of Baiyanghe Uranium Deposit In Xinjiang

Baiyanghe uranium deposit in Xinjiang Province is an explored ore deposit in China at present, and the study on its alteration characteristics will contribute to the prospecting in the periphery and deep of the area. Hyperspectral remote sensing technology can identify the altered minerals speedily and effectively, and get alteration information related to mineralization. Using the ASD visible light-short wave infrared field spectrograph of the United States, the study carried out spectrum testing and analytical investigation on the surface and drill core of Baiyanghe deposit, verified the near-infrared- short wave infrared SASI airborne hyperspectral remote sensing mineral mapping results of the deposit and its periphery, and then summarized the alteration characteristics of the surface and drill core of the deposit. The analysis shows that:(1) The altered minerals in the surface of the ore deposit mainly include: rich-Al sericite, medium-Al sericite, hematite and a little kaolinite and poor-Al sericite, etc. The alteration characteristics of the surface and the airborne hyperspectral remote sensing are concordant and obvious in zoning,The alteration of deposit surface uranium mineralization anomaly area is mainly in rich-Al sericite and hematite.(2) Hydrothermal alteration minerals in the drill core mainly include rich-Al sericite, medium-Al sericite, poor-Al sericite, chlorite, and a little kaolinite, montmorillonite, carbonate, hematite and limonite, etc. The altered mineral assemblages are: the altered mineral assemblage at the upper part of the drill is low-Al sericite + montmorillonite + a little hematite and limonite; the altered mineral assemblage in the middle is medium-Al sericite + montmorillonite + a little carbonate, hematite and limonite; the altered mineral assemblage in the bottom is chlorite + rich-Al sericite + a little carbonate.(3) Through the study on the change rules of the typical drill core hyperspectral sericite A1-OH absorption peaks, the rules of the change in hydrothermal alteration fluid of Baiyanghe deposit is primarily found. Namely, the temperature of the alteration fluid changes from relatively high in the deep to middle in vicinity of the contact zone, and then to relatively low in granite porphyry of the upper part. The change of the fluid faintly acid to alkalescence shows that hydrothermal activity is frequent during the formation of Baiyanghe uranium deposit and the deposit has experienced many times of such activities.(4) Uranium mineralization mainly happens in the alteration development area of rich-Al sericite, medium-Al sericite and hematitization, especially in their transitional zone. This reflects that uranium mineralization is mainly concerned with hematitization, rich-Al sericite and medium-Al sericite, and especially the co-existing area of the three maybe the favorable section for uranium mineralization, which provides an important reference to the prospecting prediction in the surface periphery of the mining area and the exploration of uranium ore in the deep.