Hyperspectral and Geochemical Analysis of Chlorites at the Gongchangling High-Grade Magnetite Deposit, NE China: Implications for Alteration Processes

Minerals

Kun Song¹  Yuzeng Yao¹  Jianfei Fu¹  Dahai Hao¹  Sishun Ma¹  Ende Wang¹ 

[1] School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China;

关键词: chlorite;    hyperspectral;    whole rock geochemistry;    Gongchangling iron deposit;    mineral exploration;   

DOI  :  10.3390/min12050629

来源: DOAJ

【 摘 要 】

The Gongchangling deposit is a representative banded iron formation (BIF) in China, in which developed several high-grade magnetite ores. The surrounding alteration rocks recorded the genesis information of the high-grade ores. However, the study related to alteration processes remains poor. In this study, we investigate the sub-types and formation temperature of chlorite using hyperspectral imaging and electronic probe microanalysis (EPMA), and deciphered the elemental migration trend during alteration processes by whole-rock geochemistry. The chlorites in the alteration rocks were divided into three sub-types according to the spectral features of the Fe-OH band near 2250 nm. The range of wavelength position is approximately 2250–2255 nm for chlorite-I, 2255–2260 nm for chlorite-II, and 2260–2265 nm for chlorite-III. The variation in Mg# is 0.32–0.44 in chlorite-I, 0.20–0.34 in chlorite-II, and 0.15–0.23 in chlorite-III, which is consistent with the range of wavelength position. The hydrothermal alteration resulted in the enrichment of iron and the depletion of silicon. The results shed new light on the recognition of chlorite sub-types and deciphered the hydrothermal alteration processes of high-grade magnetite ores, which proposed an effective method for mineralogical mapping.

【 授权许可】

Unknown