Shortwave Infrared Spectroscopy and Geochemical Characteristics of White Mica-Group Minerals in the Sinongduo Low-Sulfide Epithermal Deposit, Tibet, China

Sinongduo is the first low-sulfidation epithermal deposit to be found in the Gangdese metallogenic belt, Xizang, China. Through the integration of Shortwave Infrared (SWIR) spectroscopy, an electron probe microanalysis (EPMA), X-ray diffraction (XRD), and three-dimensional modeling, the following findings were obtained: (1) The alteration minerals in the belt predominantly belong to the white mica group, with mineral assemblages of muscovite → muscovite + illite → muscovite + illite + montmorillonite → muscovite + paragonite + montmorillonite → muscovite + paragonite + illite + montmorillonite from the outer edges to the ore zones. (2) On the basis of the number of interlayer cations, the white mica-group minerals were classified into three distinct types. (3) The SWIR spectral exploration model indicates the spatial distribution of the mineral combinations and their spectral characteristics in the low-sulfidation epithermal deposit. On the basis of these results, we predict that Woruo, an area located north of Sinongduo, has immense potential for future mineral exploration.