Analysis of ore-controlling structure in the Changgou gold deposit of the northern Hanyin gold orefield, southern Qinling Mountains
-
摘要: 南秦岭汉阴北部金矿田含矿岩系主要是志留系梅子垭岩组中浅变质岩层,该套地层经历了中生代的构造变形,复杂多样,其中发育的脆-韧性剪切带成为梅子垭岩组发育蚀变岩型金矿富集的良好场所。通过对汉阴北部金矿田近年新发现的长沟金矿区及周邻区带成矿地质背景、控矿构造特征等进行解析研究,结合以往资料,总结汉阴北部金矿田该类型金矿床的控矿构造特征和成矿规律,初步探讨长沟金矿床的热液成因类型。研究发现汉阴北部金矿田区发育有五条脆-韧性剪切带,其构造样式、变质作用具多样性和多期性,其中第二期变形与金成矿作用关系密切;长沟金矿区受区域DSZ3(≈RF5)脆-韧性剪切带及多期构造置换中的S2面理控制,控矿构造样式具有斜列排布特征。含矿流体包裹体研究认为其在低—中温热液环境形成,主要是在退变质作用下易于在局部两种岩性差异界面附近、片理面之间薄弱变形带、密集剪切节理带或劈理化带等有利构造部位含金热液发生富集成矿。因此,脆-韧性剪切带及其多期面理置换与密集片理、剪切节理带及热液蚀变岩是主要的控矿构造类型。进一步的找矿预测工作主要应该紧抓其脆-韧性剪切带的走向延伸和倾向延深,更应重视侧向斜列富集规律。Abstract: The ore-bearing rock series in the northern Hanyin gold orefield of the southern Qinling mountains mainly consists of the shallow metamorphic rocks in the Silurian Meiziya formation,which underwent complex tectonic deformation in Mesozoic,and the brittle-ductile shear zone is a good place for the enrichment of altered rock type gold deposits in the Meiziya formation. Based on the comprehensive analysis of the metallogenic geological background and ore-controlling tectonic characteristics of the newly discovered Changgou gold deposit and its adjacent areas in the northern Hanyin gold orefield in recent years,the ore-controlling tectonic characteristics and ore-forming rules of this type of gold deposits in the northern Hanyin gold orefield are summarizes,and the hydrothermal genetic type of the Changgou gold deposit is preliminarily discussed. It is found that there are five brittle-ductile shear zones developed in the northern Hanyin gold orefield,and their tectonic patterns and metamorphism are diverse and multistage,among which the second deformation is closely related to gold mineralization. The Changgou gold mining area is controlled by the regional brittlle-ductile shear zone DSZ3 (≈RF5) and S2 bedding in multi-stage tectonic replacement,and the ore-controlling structure is characterized by oblique arrangement. The study of ore-bearing fluid inclusions shows that the formation of ore-bearing fluid inclusions in low-medium-temperature hydrothermal environment is mainly due to the accumulation and mineralization of gold-bearing hydrothermal fluids in favorable tectonic areas such as the weak deformation zone,dense shear joint zone or cleavage zone near the interface of two local lithologic differences and between foliation planes. Therefore,the brittlle-ductile shear zone and its multi-phase plane displacement and dense foliation,shear joint zone and hydrothermal altered rock are the main ore-controlling structural types. Further prospecting and prediction work should focus on the trend extension and dip extension of the brittle-ductile shear zone,and more attention should be paid to the law of lateral oblique accumulation.
-
图 1 汉阴北部金矿田韧性剪切带与金矿床点平面分布图(据杨兴科等,2012修改)
1-梅子娅组;2-斑鸠关组;3-奥陶系;4-寒武系;5-耀岭河岩组;6-武当岩群;7-脆-韧性剪切带及代号;8-断裂;9-花岗岩脉;10-灰岩条带;11-褐铁矿化条带;12-剖面及其编号;13-常规产状及面理产状;14-矿床(点)
Figure 1. Plane distribution of ductile shear zones and gold deposits (points) in the northern Hanyin gold orefield (modified after Yang et al., 2012)
图 12 长沟矿区脆-韧性剪切带破碎蚀变岩型金矿控矿构造模型(据杨兴科等,2015;何虎军等,2019修改)
Figure 12. Ore-controlling tectonic model of the fracture altered rock type gold deposit in the ductile shear zone of the Changgou mining area(modified after Yang et al., 2015; He et al., 2019)
表 1 长沟金矿区主要金矿体特征表
Table 1. Characteristics of main gold ore bodies in the Changgou gold mining area
矿体编号 出露标高/m 出露长度/m 平均厚度/m 平均品位/×10-6 平均产状/(倾向(°)∠倾角(°)) K1 700~758 460 2.20 1.54 343°∠50° K2 711~748 190 1.92 1.52 206°∠48° K4 534~712 1100 2.14 2.60 25°∠67° -
BAI L A, 2005. Geological characteristics and ore-searching marks in Huanglong au deposit[J]. Contributions to Geology and Mineral Resources Research, 20(S1):24-27. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzzklc2005z1006 CHEN Y J, 2010. Indosinian tectonic setting, magmatism and metallogenesis in Qinling Orogen, central China[J]. Geology in China, 37(4):854-865. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zgdizhi201004003 DENG J, SUN Z S, WANG J P, et al., 2001. Dynamic system transformation and gold ore-forming process[J]. Mineral Deposits, 20(1):71-77. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/kcdz200101008 DU J, 2014. Discussion on the geological characteristics and prospecting potential of Silurian gold-bearing deposit in north Ankang[J]. China Mine Engineering, 43(5):39-43. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ysks201405012 GAO Y N, YANG X K, YANG L W, et al., 2016. Study on ore-controlling factors and mine exploration proposal of the gold ore field in north Hanyin, south Qinling[J]. Journal of Geomechanics, 22(2):245-255. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzlxxb201602006 Geology and mineral resources bureau of shaanxi province, 1993. Report of 1: 50, 000 regional geological survey of Yingfeng street and Tiefo temple[R]. Xi'an: Geology and mineral resources bureau of shaanxi province. (in Chinese) HAN K, YANG X K, ZHANG J, et al., 2017. Characteristics of brittle ductile shear zone and its control on mineralization of Huanglong gold deposit in Hanyin, southern Shaanxi[J]. Gold Science and Technology, 25(5):18-29. (in Chinese with English abstract) HE H J, HAN K, YANG X K, et al., 2019. Controls on the formation of the Changgou gold deposit and implications for exploration within the North Hanyin area, South Qinling Mountains, China[J]. Geological Journal, 54(4):2431-2446. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=10.1002/gj.3305 LU X X, LI M L, WANG W, et al., 2008. Indosinian movement and metallogenesis in Qinling orogenic belt[J]. Mineral Deposits, 27(6):762-773. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=kcdz200806009 Shaanxi Geological Survey, 2007. Report of 1: 250000 regional geological survey in Ankang city[R]. Xi'an: Shaanxi Geological Survey. (in Chinese) WANG X, 2017. Characteristics of fluid inclusions and genesis of Changgou gold deposits in Hanyin county, Shaanxi province[D]. Xi'an: Chang'an University. (in Chinese with English abstract) WANG Y W, LI X Z, YAN Z B, et al., 1987. Geology and prospecting methods of gold deposits in China[M]. Xi'an: Shaanxi Bureau of Geology and Mineral Resources: 56-59. (in Chinese) WU W R, WANG B Y, 1991. The formation and evolution of ductile shear belt in the middle part of the south Qinling orogenic belt in Shaanxi province and its relationship with gold mineralization[R]. Xi'an: Shaanxi Geology and Mining Bureau. (in Chinese) YANG L W, YANG X K, HAN K, et al., 2018. Fluid inclusions of the Changgou gold deposit in North Hanyin, South Qinling[J]. Northwestern Geology, 51(2):178-185. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/xbdz201802024 YANG X K, GONG T L, 1992. A brief discussion on dynamic hydrothermal mineralization——a case study of lead-zinc deposit in lead-Adongshan[J]. Northwestern Geology, 13(4):10-14. (in Chinese) YANG X K, CHEN Q, ZHANG L C, 1999. Brittle ductile conversion and dynamic metallogenic process analysis[J]. Acta Geologica Sinica, 20:26-31. (in Chinese) Yang X K, Zhang K, Li X, et al., 2010. Structural characteristics and prospecting prediction of altered rock type gold deposit in ductile shear zone[C].//Committee of geomechanics of Chinese society of geology, Professional committee of structural geology and geodynamics, geological society of China, Proceedings of the third national symposium on structural and geological prospecting theories and methods in ore fields. Xi'an: editorial department of the journal of earth science and environment: 165-167. YANG X K, HE H J, ZHANG K, et al., 2012. The structure of the Liufang Silurian gold field in Tiefousi-Hanbin district, Hanyin county, Ankang city, Shaanxi province and the method of rapid evaluation and exploration[R]. Xi'an: Chang'an University. (in Chinese) YANG X K, He H J, Gao Y N, et al., 2016a. Study on prospecting prediction in key working areas of integrated exploration area of Shiquan-Sunyang gold mine in Shaanxi[R]. Xi'an: Chang'an University. (in Chinese) YANG X K, HAN K, WU X, et al., 2016b. The structural deformation and tectonic evolution of intra-continental orogeny in South Qinling orogen:Structural deformation analysis of the northern part of Shiquan-Hanyin belt in the late Indosinian-Yanshanian period[J]. Earth Science Frontiers, 23(4):72-80. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/dxqy201604006 YANG Z H, ZHU Z J, WANG B Y, et al., 2002. Two phases over-thrusting nappe in Shanyang-Zhashui-Xunyang-Ankang region of the South Qinling and the basic characteristics of Ⅱ-type orogenic belt[J]. Northwestern Geology, 35(1):1-14. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=xbdz200201001 ZHANG G W, 1991. A discussion on basic features of tectonic development of lithosphere of the Qinling Belt[J]. Journal of Northwest University, 21(2):77-87. (in Chinese with English abstract) ZHANG G W, DONG Y P, YAO A P, 1997. The crustal compositions, structures and tectonic evolution of the Qinling Orogenic belt[J]. Geology of Shaanxi, 15(2):1-14. (in Chinese with English abstract) ZHANG G W, MENG Q R, LAI S C, 1995. Tectonics and structure of Qinling orogenic belt[J]. Science in China (Series B), 38(11):1379-1394. http://d.old.wanfangdata.com.cn/Periodical/OA000002705 ZHANG G W, GUO A L, LIU F T, et al., 1996. Three-dimentional architecture and dynamic analysis of the Qinling Orogenic Belt[J]. Science in China (D), 26(S1):1-6. (in Chinese with English abstract) ZHANG G W, GUO A L, DONG Y P, et al., 2019.Rethinking of the Qinling orogen[J].Journal of Geomechanics, 25(5):746-768 http://d.old.wanfangdata.com.cn/Periodical/dzlxxb201905009 ZHANG K, 2012. Ore-controlling rules and prospecting indicator of silurian system gold field Structure in North Navin, South Qinlin[D]. Xi'an: Chang'an University. (in Chinese with English abstract) ZHANG S N, LIU J C, YANG X K, 2012. Study on the characteristics and forming temperature and pressure conditions of epimetamorphic rocks in the Hanyin gold deposit in southern Shaanxi[J]. Northwestern Geology, 45(S1):170-172. (in Chinese) ZHENG J X, ZHAO T Y, HAN Q, et al., 2019. Tectonic deformation characteristics and ore-control significance of the Sanjiashan ductile shear zone in Beishan orogenic belt, Xinjiang[J]. Journal of Geomechanics, 25 (S1):032-038. ZHU J J, LIN G, ZENG Q S, 2018. Relationship between slip surfaces and auriferous orebodies and its metallogenic significance in the Hetai gold deposit, Guangdong[J]. Mineral Exploration, 9(3):333-341. (in Chinese with English abstract) http://d.old.wanfangdata.com.cn/Periodical/ytgcj201803008 ZHU L M, ZHANG G W, Li B, et al., 2008. Main geological events, genetic types of metallic deposits and their geodynamical setting in the Qinling Orogenic belt[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 27(4):384-390. (in Chinese with English abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=kwysdqhxtb200804009 白龙安, 2005.陕西省汉阴县黄龙金矿床地质特征及找矿标志[J].地质找矿论丛, 20(S1):24-27. http://d.old.wanfangdata.com.cn/Periodical/dzzklc2005z1006 陈衍景, 2010.秦岭印支期构造背景、岩浆活动及成矿作用[J].中国地质, 37(4):854-865. http://d.old.wanfangdata.com.cn/Periodical/zgdizhi201004003 邓军, 孙忠实, 王建平, 等, 2001.动力系统转换与金成矿作用[J].矿床地质, 20(1):71-77. http://d.old.wanfangdata.com.cn/Periodical/kcdz200101008 杜坚, 2014.安康北部志留系金矿地质特征及找矿前景探讨[J].中国矿山工程, 43(5):39-43. http://d.old.wanfangdata.com.cn/Periodical/ysks201405012 高雅宁, 杨兴科, 杨龙伟, 等, 2016.南秦岭汉阴北部金矿田控矿要素研究及找矿方向建议[J].地质力学学报, 22(2):245-255. https://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20160206&journal_id=dzlxxb 韩珂, 杨兴科, 张健, 等, 2017.陕南汉阴黄龙金矿脆-韧性剪切带特征及其对成矿的控制作用[J].黄金科学技术, 25(5):18-29. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=9783637 卢欣祥, 李明立, 王卫, 等, 2008.秦岭造山带的印支运动及印支期成矿作用[J].矿床地质, 27(6):762-773. http://d.old.wanfangdata.com.cn/Periodical/kcdz200806009 陕西省地质调查院, 2007.安康市幅I49C004001 1/25万区域地质调查报告[R].西安: 陕西省地质调查院. 陕西省地质矿产局, 1993.迎丰街、铁佛寺幅1/5万区调联测报告[R].西安: .陕西省地质矿产局. 王新, 2017.陕西省汉阴县长沟金矿流体包裹体特征及矿床成因研究[D].西安: 长安大学. 王友文, 李兴柱, 阎竹斌, 等, 1987.中国金矿地质及普查勘探方法[M].西安: 陕西省地质矿产局: 56-59. 吴闻人, 王北颖, 1991.陕西省南秦岭造山带中部韧性剪切带的形成、演化及其与金矿成矿关系研究[R].西安: 陕西省地矿局. 杨龙伟, 杨兴科, 韩珂, 等, 2018.南秦岭汉阴北部长沟金矿床流体包裹体特征[J].西北地质, 51(2):178-185. http://d.old.wanfangdata.com.cn/Periodical/xbdz201802024 杨兴科, 宫同伦, 1992.动力热液成矿作用简论:以铅硐山铅锌矿床为例[J].西北地质, 13(4):10-14. 杨兴科, 陈强, 张连昌, 1999.脆-韧性转换与动力成矿过程分析[J].地球学报, 20:26-31. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=186400 杨兴科, 张康, 李希, 等, 2010.韧性剪切带蚀变岩型金矿田构造特征与找矿预测[C].//中国地质学会地质力学专业委员会, 中国地质学会构造地质学与地球动力学专业委员会.第三届全国矿田构造与地质找矿理论方法研讨会论文集.西安: 《地球科学与环境学报》编辑部: 165-167. 杨兴科, 何虎军, 张康, 等, 2012.陕西安康汉阴县铁佛寺-汉滨区流芳志留系金矿田构造及快速评价勘查方法[R].西安: 长安大学. 杨兴科, 何虎军, 高雅宁, 等, 2016a.陕西石泉-旬阳金矿整装勘查区专项填图与找矿预测研究报告[R].西安: 长安大学. 杨兴科, 韩珂, 吴旭, 等, 2016b.南秦岭陆内造山构造变形特征与演化:石泉-汉阴北部一带晚印支-燕山期构造变形分析[J].地学前缘, 23(4):72-80. http://d.old.wanfangdata.com.cn/Periodical/dxqy201604006 杨志华, 朱志军, 王北颖, 等, 2002.南秦岭山柞旬-安康地区的两次逆冲推覆和Ⅱ型造山带基本特征[J].西北地质, 35(1):1-14. http://d.old.wanfangdata.com.cn/Periodical/xbdz200201001 张国伟, 1991.试论秦岭造山带岩石圈构造演化基本特征[J].西北大学学报, 21(2):77-87. 张国伟, 孟庆任, 赖绍聪, 1995.秦岭造山带的结构构造[J].中国科学(B辑), 25(9):994-1003. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199500247435 张国伟, 郭安林, 刘福田, 等, 1996.秦岭造山带三维结构及其动力学分析[J].中国科学(D辑), 26(S1):1-6. http://d.old.wanfangdata.com.cn/Conference/361004 张国伟, 董云鹏, 姚安平, 1997.秦岭造山带基本组成与结构及其构造演化[J].陕西地质, 15(2):1-14. doi: 10.1016-j.tetasy.2009.09.016/ 张国伟, 郭安林, 董云鹏, 等, 2019.关于秦岭造山带[J].地质力学学报, 25(5):746-768. https://journal.geomech.ac.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20190508&journal_id=dzlxxb 张康, 2012.南秦岭汉阴北部志留系金矿田构造控矿规律及找矿标志研究[D].西安: 长安大学. 张苏楠, 刘建朝, 杨兴科, 2012.陕南汉阴金矿田中浅变质岩特征及形成温压条件探讨[J].西北地质, 45(S1):170-172. http://d.old.wanfangdata.com.cn/Periodical/xbdz2012z1048 郑加行, 赵同阳, 韩琼, 等., 2019.新疆北山地区三架山韧性剪切带构造变形特征及控矿意义[J].地质力学学报, , 25(S1):032-038. 朱江建, 林舸, 曾乔松, 2018.广东河台金矿滑痕线理与金矿体的关系及成矿意义[J].矿产勘查, 9(3):333-341. http://d.old.wanfangdata.com.cn/Periodical/ytgcj201803008 朱赖民, 张国伟, 李犇, 等, 2008.秦岭造山带重大地质事件、矿床类型和成矿大陆动力学背景[J].矿物岩石地球化学通报, 27(4):384-390. http://d.old.wanfangdata.com.cn/Periodical/kwysdqhxtb200804009