Abstract:
Objective Baiyinwula deposit is located in the tungsten−tin polymetallic mineralization belt in the southern section of Great Xing’an Range, which has good prospecting of rare metals. However, in the process of mineral exploration, there have been problems such as unclear hydrothermal mineralization centers and insufficient understanding of the genesis of mineral deposits, which have affected the effectiveness of mineral exploration.
Methods In this paper, the alteration mineral types and relative contents in this deposit were analyzed by using short−wave infrared spectroscopy.
Results The results show that the alteration minerals are dominated by muscovite, phengite, illite, chlorite, biotite, topaz and tourmaline, with small amounts of kaolinite, dickite, montmorillonite and calcite. Based on the alteration mineral mapping, two alteration zones are recognized in this deposit: a strong greisenization zone (quartz−phengite−topaz−chlorite−fluorite±biotite±tourmaline) in the middle and deep parts, and a muscovite−chlorite zone (quartz−chlorite−muscovite±biotite±tourmaline) in the shallow parts and the periphery. The spatial relationship between greisenization zone and biotite granite indicate that the hydrothermal fluids derived from the biotite granite and the strong greisenization zone represent the hydrothermal and mineralization center. The characteristic spectral parameters of white−mica group minerals show that the Pos2200 and IC values are relatively high within the strong greisenization zone, and decrease further away from the zone. The increase in Pos2200 is influenced by the composition of the ore−forming fluid, the properties of the surrounding rock, and temperature, while the IC value is mainly related to the temperature of hydrothermal fluid.
Conclusions High IC value (>2) of muscovite can be used as indicator for prospecting in this deposit. Short wave infrared spectroscopy technology is a very effective exploration method in F−rich granitic magma hydrothermal systems with greisenization. The rapid identification of F−rich topaz may also suggest good exploration potential for Li and Be. The discovery of magmatic−hydrothermal Be mineralization dominated by Beryl in this deposit demonstrates the good application prospects of short wave infrared spectroscopy technology, and also reveals the diversity of Be mineralization types in Great Xing’an Range, implying good potential for Be exploration in the region. It has certain enlightening significance for future exploration targets and directions of rare metals in this region.