Microfabric Characteristics of Cherts of Bafangshan-Erlihe Pb-Zn Ore Field in the Western Qinling Orogen
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摘要:
硅质岩是造山带内广泛发育的一类岩石, 该岩石的组成以SiO2为主, 具有较高的稳定性.对于经历过造山作用、成矿作用和重结晶作用等影响的硅质岩, 其宏观组构和微观组构特征可以很好地反映它所遭受到的改造.秦岭造山带西段八方山-二里河Pb-Zn矿的宏观及微观组构特征分析表明: 该区硅质岩具有明显的热水沉积特征.由于受到压扭性和张性两种性质的应力作用, 矿区在宏观上形成了东西向压扭性断裂和北北东、北北西两组张性断裂, 微观上形成了微裂隙、微褶皱和压扁拉长的石英颗粒.矿区岩石发生了明显的变质作用, 除应力作用造成的动力变质作用外, 还发生了其他类型的变质作用和重结晶作用.硅质岩中微量碳酸岩矿物的存在以及应力作用对矿床的形成具有非常重要的意义, 特别是其可以为金属硫化物热液提供运移的通道和沉淀成矿的空间.
Abstract:With high stability, chert is widely distributed in the orogens, whose major composition is SiO2.Affected by the orogeny, metallogenesis and recrystallization, the metamorphic processes can be well revealed by the megatectonics and microfabric characteristics.The study of the megatectonics and microfabric characteristics of the cherts of Bafangshan-Erlihe Pb-Zn ore field in the western Qinling orogen reveals that there are obvious hydrothermal sedimentary characteristics in the cherts.Because of the stresses, two types of which are extensional and compresso-shear, there are megatectonics of compresso-shear faults with EW direction and gapping faults with NNE and NNW directions.What's more, there are microfabric characteristics of microcracks and microcorrugations and stretched-out grains of quartzs.In the rocks of this ore deposit field, the dynamic metamorphism, metamorphic recrystallization and other kinds of metamorphisms are clearly revealed.The trace carbonate minerals and the stress are both important to the metallogenesis of this ore deposit, which provide the pathway and space for the metallic sulphide fluids to travel and deposit.
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Key words:
- western Qinling /
- Pb-Zn ore /
- fabric analysis /
- metallogenesis /
- hydrothermal sedimentation
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图 1 八方山-二里河Pb-Zn矿矿床地质图(底图据田民民等, 2004修改)
F1. 商州-丹凤断裂; F2. 礼县-山阳断裂; F3. 临潭-镇安断裂; F4. 略阳-玛曲断裂; Fa. 压扭性断层; Fb. 张性横断层; Fc. 张性纵断层; D3x3. 砂质千枚岩; D3x2. 绿泥石千枚岩; D3x1. 铁白云石-炭质千枚岩; D2g2. 灰岩; δμ. 闪长玢岩
Fig. 1. Geological map of the Bafangshan-Erlihe Pb-Zn deposit
图 2 显微镜微下硅质岩的微裂隙(a)和微褶皱(b)
Fig. 2. Micrographs of the fissure (a) and cataclase crystal (b) in cherts_x10
图 4 含矿岩石的显微图片及拉曼定向分析结果(A→J)
Fig. 4. Micrographs and Raman shift for mine-bearing rocks
图 7 硅质岩的SEM图像
M_C.碳酸盐; M_Q.石英; M_S.硫化物; M_S(Pyr).黄铁矿
Fig. 7. SEM of metallic and carbonate minerals in cherts
图 8 硅质岩中碳酸盐矿物颗粒附近的金属硫化物分布形式
a.环状分布; b, 零星状和裂隙充填分布; c.裂隙充填分布; P.能谱测试点位
Fig. 8. Distribution of the metallic sulphide near the carbonate minerals in cherts
表 1 曲线上不同点位特征拉曼峰强度比值
Table 1. Ratio values of the characteristic peak intensity
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Fang, W. X., Liu, F. J., Hu, R. Z., et al., 2000. The characteristics and diagenetic-metallogenic pattern for cherts and siliceous ferrodolomitites from Fengtai apart-pull basin, Qinling orogen. Acta Petrologica Sinica, 16(4): 700-710(in Chinese with English abstract). Institute of Regional Geological & Mineral of Shaanxi Province, 1989. Regional geology of Shaanxi Province. Geological Publishing House, Beijing, 1-698(in Chinese). Ji, S. F., Xiao, T. C., Li, S. B., et al., 2003. Surface WO4 tetrahedron: The essence of the oxidative coupling of methane over M-W-Mn/SiO2 catalysts. Journal of Catalysis, 220: 47-56. doi: 10.1016/S0021-9517(03)00248-3 Ke, Y. K., Dong, H. R., 1998. Analysis chemistry(3): Spectrum analysis. Chemical Industry Press, Beijing(in Chinese). Li, H. Z., Yang, Z. J., Zhou, Y. Z., et al., 2007. The characteristics of chert of Qinling area and its prospect. Acta Mineralogica Sinica, (Suppl. ): 441-443(in Chinese with English abstract). Li, Q., Xue, C. J., Liu, S. W., et al., 2007. Research on the paragenesis(coexist) relationship of lead-znic and gold mineralization in the Bafangshan-Baguamiao deposit, Fengxian County, southern Qinling Mountains. Geological Review, 53(1): 65-74(in Chinese with English abstract). Lü, R. S., Wei, H. M., 1990. The geological characteristics and genetic investigation of Bafangshan stratabound polymetallic ores in Shaanxi Province. Journal of Xi'an College of Geology, 12(4): 10-17(in Chinese with English abstract). Lynne, B. Y., Campbell, K. A., Moore, J. N., et al., 2005. Diagenesis of 1900-year-old siliceous sinter(opal-A to quartz)at Opal Mound, Roosevelt Hot Springs, Utah, U. S. A. . Sedimentary Geology, 179(3-4): 249-278. doi: 10.1016/j.sedgeo.2005.05.012 Murray, R. W., 1994. Chemical criteria to identify the depositional environment of chert: General principles and applications. Sedimentary Geology, 90(3-4): 213-232. doi: 10.1016/0037-0738(94)90039-6 Ostroumov, M., Faulques, E., Lounejeva, E., 2002. Raman spectroscopy of natural silica in Chicxulub impactite, Mexico. C. R. Geosciences, 334(1): 21-26. doi: 10.1016/S1631-0713(02)01700-5 Sylvain, B., Karim, B., Olivier, B., et al., 2007. Exceptional preservation of fossil plant spores in high-pressure metamorphic rocks. Earth and Planetary Science Letters, 262(1-2): 257-272. doi: 10.1016/j.epsl.2007.07.041 Tian, M. M., Yuan, X. D., Zhang, Y. R., et al., 2004. Discussion of geological prospecting in Erlihe Pb-Zn deposit, Fengxian. Mineral Resources and Geology, 18(102): 134-138(in Chinese with English abstract). Wang, J. F., Zhang, F. X., Yan, J. C., et al., 1991. Devonian stratabound metalliferous deposit in Qinling. Shaanxi Science and Technology Press, Xi'an, 1-71(in Chinese). Wang, J. L., He, B. C., Li, J. Z., et al., 1996. Qinling-type lead-zinc deposits in China. Geological Publishing House, Beijing, 1-126(in Chinese). Xu, P. C., Li, R. B., Wang, Y. Q., et al., 1996. Raman spectroscopy to the earth science. Shaanxi Science and Technology Press, Xi'an, 1-176(in Chinese). Xue, C. J., 1997. Devonian hydrothermal sedimentation in Qinling. Xi'an Cartographic Publishing House, Xi' an, 1-134(in Chinese). Yang, Z. J., Li, H. Z., Peng, M. S., et al., 2008. Study on the HPHT synthetic diamond crystal from Fe-C(H) system and its significance. Chinese Science Bulletin, 53 (1): 139-146. doi: 10.1007/s11434-008-0020-3 Yang, Z. J., Zhou, Y. Z., Zhang, C. B., et al., 2003. The research of fabric information in the siliceous rock and its significance. Bulletin of Mineralogy Petrology and Geochemistry, 22(3): 255-258(in Chinese with English abstract). https://www.researchgate.net/publication/290229654_The_research_of_fabric_information_in_the_siliceous_rock_and_its_significance Yoshikawa, M., Lwagami, K., Morita, N., et al., 1997. Characterization of fluorine-doped silicon dioxide film by Raman spectroscopy. Thin Solid Films, 310(1-2): 167-170. doi: 10.1016/S0040-6090(97)00393-3 Zhou, Y. Z., Fu, W., Yang, Z. J., et al., 2006. Microfabrics of chert from Yarlung Zangbo suture zone and southern Tibet and its geological implications. Acta Petrologica Sinica, 22(3): 742-750(in Chinese with English abstract). 方维萱, 刘方杰, 胡瑞忠, 等, 2000. 凤太泥盆纪拉分盆地中硅质铁白云岩-硅质岩特征及成岩成矿方式. 岩石学报, 16 (4): 700-710. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200004037.htm 柯以侃, 董慧茹, 1998. 分析化学手册(3): 光谱分析. 北京: 化学工业出版社. 李红中, 杨志军, 周永章, 等, 2007. 秦岭地区硅质岩的地质地球化学特征及研究展望. 矿物学报, (增刊): 441-443. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200911037.htm 李强, 薛春纪, 刘淑文, 等, 2007. 南秦岭凤县八方山-八卦庙Pb-Zn与Au矿化的共生/共存关系研究. 地质评论, 53 (1): 65-74. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP200701008.htm 吕仁生, 隗合明, 1990. 八方山层控多金属矿床地质特征及成因探讨. 西安地质学院学报, 12 (4): 10-17. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGX199004001.htm 陕西省地质矿产局, 1989. 陕西省区域地质志. 北京: 地质出版社, 1-698. 田民民, 袁旭东, 张永让, 等, 2004. 凤县二里河铅锌矿床后续地质找矿探讨. 矿产与地质, 18 (102): 134-138. https://www.cnki.com.cn/Article/CJFDTOTAL-KCYD200402009.htm 王俊发, 张复新, 炎金才, 等, 1991. 秦岭泥盆系层控金属矿床. 西安: 陕西科学技术出版社, 1-71. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDZ199204003.htm 王集磊, 何伯墀, 李健中, 等, 1996. 中国秦岭型铅锌矿床. 北京: 地质出版社, 1-126. 徐培苍, 李如壁, 王永强, 等, 1996. 地学中的拉曼光谱. 西安: 陕西科学技术出版社, 1-176. 薛春纪, 1997. 秦岭泥盆纪热水沉积. 西安: 西安地图出版社, 1-134. 杨志军, 周永章, 张澄博, 等, 2003. 硅质岩组构信息研究及其意义. 矿物岩石地球化学通报, 22 (3): 255-258. doi: 10.3969/j.issn.1007-2802.2003.03.013 周永章, 付伟, 杨志军, 等, 2006. 雅鲁藏布江缝合带及藏南地区硅质岩微组构特征及其地质意义. 岩石学报, 22 (3): 742-750. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200603024.htm -
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