Micro Raman Spectral Characteristics and Implication of Pyrite in the Jiaojia Gold Deposit, Jiaodong Area, Shandong Province, China
YAO Chang1, SONG Hao1, 2*, LI Qi1, LI Na1, ZHANG Gang-yang1
1. College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
2. Key Laboratory of Nuclear Techniques in Geosciences of Sichuan Province, Chengdu 610059, China
Abstract：Pyrite is one of the most common metallic minerals in gold deposits. It not only has a close relationship with the gold mineralization, but also serves as the main gold-carrier. Therefore, pyrite can provide much information for growth and forming of gold. However, previous scholars study the pyrite in gold deposits by a series of geochemistry methods, such as EPMA or SIMS, to quantify the gold content and trace elements. Nevertheless, these methods are not only highly expensive but also time-spending. Therefore, we need an efficient and reliable technology. Raman spectroscopy, more convenient and reliable, is used in materials science to identify molecules and study chemical bonding and intramolecular bonds. So, it might be regarded as an effective geological tool. Therefore, we will study the formation and structure of pyrite in different alteration zones by Raman spectrum and petrography in this paper. The Jiaojia gold deposit is located in Jiaodong area, the most important gold resources in China currently. Jiaojia gold mine is a typical altered rock type deposit, with the prominent alteration zonation and structural ore-control characteristics. The wall rock is the Linglong granite and pyrite is the main ore minerals. The wall rock alteration along the fault zone in the mining area, and the wall rock alterations are mainly composed of K-feldsparization, sericitization, pyritization. By studying the Raman spectral peak data of samples in different depths and alteration zones, we discuss the Raman shift and the half height width (FWHM) of the characteristic peak of pyrite including their geological significance. Analyzing result shows that though the Raman shift of Ag has some deviation in transforming part of different alterations, it has an obviously positive correlation with the depth roughly. Pyrite in the ore body and sericitization-zone FWHM value (median) are mainly concentrated in 3.3, 3.2~5.5 cm-1 respectively. In the K-feldspathization-halo which is located away from the ore body, FWHM value (median) is concentrated in 4.1~8.4 cm-1. We can find that the FWHM declines from K-feldspathization-halo (shallow depth) to ore body firstly, then it increases gradually to K-feldspathization-halo (deep depth). We deem that from the K-feldspathization-halo to the ore body, the crystallinity and order degree of pyrite are becoming higher and higher, and the pyrite in K-feldspathization-halo has a trend to change into low crystallinity and disorder. On the other hand, it implicates that the pyrite in different alteration zones various forming temperature. So, it is not difficult to find that the pyrite in alteration zones is forming at a higher temperature with the low crystalline degree. Pyrite in the ore body are forming at a lower temperature with the high crystalline degree. This phenomenon agrees well with the petrographic study previously. In addition, we also assume that the formation temperature of pyrite for various depths is distributed symmetrically. It fits roughly to the distribution of alteration zones.
姚 畅，宋 昊，李 圻，李 娜，张刚阳. 胶东焦家金矿床中黄铁矿拉曼光谱特征及其成因指示意义[J]. 光谱学与光谱分析, 2020, 40(08): 2479-2483.
YAO Chang, SONG Hao, LI Qi, LI Na, ZHANG Gang-yang. Micro Raman Spectral Characteristics and Implication of Pyrite in the Jiaojia Gold Deposit, Jiaodong Area, Shandong Province, China. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(08): 2479-2483.
[1] Fan H R, Zhai M G, Xie Y H, et al. Mineralium Deposita, 2003, 38(6): 739.
[2] GAO Zhen-min, YANG Zhu-sen, LI Hong-yang, et al（高振敏，杨竹森，李红阳，等）. Geological Journal of China Universities（高校地质学报）, 2000, 6(2): 156.
[3] Mills S E, Tomkins A G, Weinberg R F, et al. Ore Geology Reviews, 2015, 71: 150.
[4] Li X C, Fan H R, Santosh M, et al. Ore Geology Reviews, 2013, 53: 403.
[5] Yoshida A, Kaburagi Y, Hishiyama Y. Carbon, 2006, 44(11): 2333.
[6] Nestler K, Dietrich D, Witke K, et al. Journal of Molecular Structure, 2003, 661-662(none): 357.
[7] BAO Zhong-yi, YANG Li-xin, TAN Jian-gang, et al（鲍中义, 杨立新，谭建刚，等）. Shandong Land and Resources（山东国土资源）, 2011, 27(10): 16.
[8] Wojdyr M. Journal of Applied Crystallography, 2010, 43：1126.
[9] Kleppe A K, Jephcoat A P, Smyth J R. Physics and Chemistry of Minerals, 2006, 32(10): 700.
[10] Kerrich R, Goldfarb R, Groves D, et al. Science in China Series D Earth Sciences, 2000, 43: 1.
[11] SHA Xi, MA Rui, LIU Zheng-hong, et al（沙 茜，马 瑞，刘正宏，等）. Journal of Mineralogy and Petrology（矿物岩石），2010, 30(4): 43.
[12] LÜ Gu-xian, LIN Wen-wei, GUO Tao, et al（吕古贤, 林文蔚, 郭 涛, 等）. Earth Science Frontiers（地学前缘）, 2001, 8(4)：253.
[13] QIN Shan(秦 善). Structural Mineralogy(结构矿物学). Beijing: Peking University Pres(北京：北京大学出版社)，2011. 35.
[14] Morga R, Jelonek I, Kruszewska K. International Journal of Coal Geology, 2014, 134-135: 17.
[15] LIU Shan-qi, LI Yong-bing, SHI Yao-lin（刘善琪, 李永兵, 石耀霖）. Acta Petrologica Sinica（岩石学报），2018, 34(6)：1813.
[16] FAN Hong-rui, et al（范宏瑞, 等）. 17th Annual Academic Conference of the Chinese Society of Mineral Petrology and Geochemistry（中国矿物岩石地球化学学会第17届学术年会），2019.
