Study on Polarization Spectroscopy of Alteration Minerals
YANG Yun-han1, SHI Wei-xin2, QIU Jun-ting1
1. National Key Lab of Science and Technology on Remote Sensing Information and Image Analysis，Beijing Research Institute of Uranium Geology, Beijing 100029, China
2. Physical Geological Data Center of Natural Resources, Sanhe 065201, China
Abstract：Objects on the ground or in the atmosphere have unique polarization characteristics when they reflect, scatter, transmit, and radiate, which can be used to solve problems that some traditional optical detectors cannot, and increase the information richness. Polarization characteristics of targets have been widely used in military, environment, agriculture, medicine and many other fields. In geology, previous pieces of literature about polarization mainly focused on petrology study, in which the polarization characteristics of rocks or rock-forming minerals were used to distinguish different rock types or to explain the mechanism of differences in rock polarization properties. Though the achievements provide important references for lithological interpretation in geological mapping, no focuses on economic geology, another important branch of geology. Since ore deposits are usually associated with alterations, it is of great scientific value and economic interest to study the polarization characteristics of alteration minerals, so that the polarization spectral technology can be used to guide ore prospecting work. In this study, we carried out polarization spectral measurement and data processing for nine porphyry-related, three that cannot be distinguished by shortwave infrared, and two that cannot be distinguished by visible light alteration minerals using instrument and software developed by Beijing Research Institute of Uranium Geology in an attempt to fill the blank on polarization characteristics of alteration minerals. The results show that the polarization spectra of alteration minerals in the potassic, propylitization, sericite and advanced argillic zones of porphyry deposits are significantly different. The differences in spectral shapes and absorption intensities can be used to identify different alteration minerals, thus divide the alteration zones. The results also suggest that the polarization characteristics of three shortwave infrared blind minerals of quartz, fluorite, and potash feldspar, and two visible-light blind minerals of calcite and dolomite are significantly different, implying that a spectrometer with polarization system can identify more kinds of alteration minerals, which further implying a new generation of micro spectrometers with polarization system could be very useful in mineral exploration. Consequently, it is necessary to carry out more further and systematic research and practice on polarization characteristics of alteration minerals.
Key words：Polarization spectroscopy; Alteration minerals; Economic geology; Mineral exploration
杨云汉，史维鑫，邱骏挺. 蚀变矿物的偏振光谱学研究[J]. 光谱学与光谱分析, 2021, 41(03): 948-953.
YANG Yun-han, SHI Wei-xin, QIU Jun-ting. Study on Polarization Spectroscopy of Alteration Minerals. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2021, 41(03): 948-953.
