陕西凤县马蹄沟——庙沟金矿区控矿构造特征
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摘要
陕西凤县马蹄沟—庙沟金矿处于华北板块与华南板块之间的唐藏—商丹构造混杂带内。矿区赋矿地层下古生界罗汉寺岩群为一套浅变质、强变形的火山—沉积岩系,经历了多期构造变形、变质作用,使得矿体形态变得更加复杂。采用矿区构造剖面与岩(矿)石切片研究方法,通过野外实地调研及构造分级分类专题研究,对区内多种类型的控矿构造样式及性质等进行了详细研究,结合岩石光薄片观察、岩石化学分析、探矿工程深部揭露和区域构造演化历史分析等方法,划分出四级控矿构造。研究表明:区内存在成矿期前剥离断层,主体控矿构造为近EW向展布的罗汉寺—瓦窑上脆—韧性断层(F9)及其NWW向派生韧—脆性剪切带和断裂破碎带;主控矿构造方向为近EW向和NWW向;矿体向北缓倾,在空间上呈复式褶皱或褶叠层样式,局部受北倾直立片理化带控制,产状较陡;与金矿体关系密切的岩脉为晚三叠世花岗斑岩脉。金成矿主体经受晚印支期脆—韧性剪切变形期热液蚀变富集,并在脆性阶段叠加有剪切带引张破裂及含金石英细脉加富。该矿床成矿类型为晚三叠世脆—韧性剪切带叠加引张破裂热液型金矿。
Matigou-Miaogou gold deposit in Fengxian County,Shaanxi Province is located in the TangzangShangdan tectonic mixed zone of the Qinling orogenic belt. Because of the multi-stage orogenic ductile and brittle tectonic activities,there are many types of superimposed composite shear zones,and deep granite magmatic intrusion during collisional orogeny,which make it an important favorable zone for gold mineralization.The Lower Paleozoic Luohansi Group is a set of shallowly metamorphic and strongly deformed volcanic-sedimentary rocks in the ore-hosting strata of the mining area. It has undergone multi-stage tectonic deformation and metamorphism. Folds and faults are well developed,which make the ore body morphology complex and can be roughly divided into north-south tectonic belts.The shape of folds is complex and varied,and the overall shape of folds is reversed S-shaped,while the fracture is a series of brittle-brittle toughness with multiple primary and secondary matching.This paper uses the research methods of structural section and slice of rock and ore in the mining area,based on the field geological facts,through the special study on hierarchical classification of the mining area structure,detailed research on various types of ore-controlling structure styles and features in the area.Combined with the methods of rock slices,petrochemical analysis and deep exploration of prospecting engineering,the history of regional tectonic evolution,divided different levels of ore-controlling structures,a four-level ore-control structure was divided. Structural profiles show that tight folds and other ductile shear deformation and dynamic metamorphism such as mylonite zone and schistosomiasis zone are developed in the mining area. Rock(ore) slices show that mylonite foliation displacement early regional foliation(phyllite,etc.)is widespread in the mining area,which can reach above the level of primary mylonite,and is multi-stage brittle and ductile superimposition transformation. Gold mineralization is related to ore type and fabric.Gold grade of alterated mylonite(10.2×10-6～17.5×10-6,weathered:4.97×10-6～6.23×10-6),especially superimposed quartz vein type,is higher than altered cataclastic rock(1.16×10-6),rock mass and boundary contact zone with the lowest grade(0.18×10-6～0.89×10-6),and is mineralized.The study concluded that there is a stripping fault before the metallogenic period. Matigou-Miaogou gold deposit is a fourth-order tectonic orecontrolling zone and a first-order Tangzang-Shangdan tectonic melange zone,which controls the distribution of metallogenic belts and ore-forming geological bodies in the area,i. e. the north-south tectonic slices and Jingshaowan back-shaped.The second-order is a nearly east-west-trending Luohansi-Wayaoshang brittle-ductile fracture(F9),which retains the characteristics of multi-stage compression brittle-ductile structure from north to south,and the section develops tectonic slices,it controls the spatial location of mineralized alteration zone.The third level is F9 which controls the NWW-NW secondary derivative brittle-ductile shear zone,which is nearly parallel to it,and controls the spatial form of ore bodies.The fourth level is the position where the occurrence of shear zone changes and the extensional fracture zone,which controls the occurrence change of orebodies and the changes of ore grade and type,such as thickening and quartz vein type superimposition and enrichment.The main ore-controlling structure extends in the direction of nearly east-west and northwest-west.The orebody dips northward gently and steeply locally,and is controlled by the vertical schistosomiasis zone of northward dip.The space may be in the form of multiple folds or fold stacks.The main gold metallogenic bodies in this area formed hydrothermal alteration and enrichment in the process of brittle-ductile shear deformation in the late Indosinian period,superimposed by enrichment of gold-bearing quartz veins in the extensional fracture zone of shear zone.The metallogenic type is Late Triassic brittle-ductile shear zone superimposed extension fracture hydrothermal gold deposit.
Matigou-Miaogou gold deposit in Fengxian County,Shaanxi Province is located in the TangzangShangdan tectonic mixed zone of the Qinling orogenic belt. Because of the multi-stage orogenic ductile and brittle tectonic activities,there are many types of superimposed composite shear zones,and deep granite magmatic intrusion during collisional orogeny,which make it an important favorable zone for gold mineralization.The Lower Paleozoic Luohansi Group is a set of shallowly metamorphic and strongly deformed volcanic-sedimentary rocks in the ore-hosting strata of the mining area. It has undergone multi-stage tectonic deformation and metamorphism. Folds and faults are well developed,which make the ore body morphology complex and can be roughly divided into north-south tectonic belts.The shape of folds is complex and varied,and the overall shape of folds is reversed S-shaped,while the fracture is a series of brittle-brittle toughness with multiple primary and secondary matching.This paper uses the research methods of structural section and slice of rock and ore in the mining area,based on the field geological facts,through the special study on hierarchical classification of the mining area structure,detailed research on various types of ore-controlling structure styles and features in the area.Combined with the methods of rock slices,petrochemical analysis and deep exploration of prospecting engineering,the history of regional tectonic evolution,divided different levels of ore-controlling structures,a four-level ore-control structure was divided. Structural profiles show that tight folds and other ductile shear deformation and dynamic metamorphism such as mylonite zone and schistosomiasis zone are developed in the mining area. Rock(ore) slices show that mylonite foliation displacement early regional foliation(phyllite,etc.)is widespread in the mining area,which can reach above the level of primary mylonite,and is multi-stage brittle and ductile superimposition transformation. Gold mineralization is related to ore type and fabric.Gold grade of alterated mylonite(10.2×10-6～17.5×10-6,weathered:4.97×10-6～6.23×10-6),especially superimposed quartz vein type,is higher than altered cataclastic rock(1.16×10-6),rock mass and boundary contact zone with the lowest grade(0.18×10-6～0.89×10-6),and is mineralized.The study concluded that there is a stripping fault before the metallogenic period. Matigou-Miaogou gold deposit is a fourth-order tectonic orecontrolling zone and a first-order Tangzang-Shangdan tectonic melange zone,which controls the distribution of metallogenic belts and ore-forming geological bodies in the area,i. e. the north-south tectonic slices and Jingshaowan back-shaped.The second-order is a nearly east-west-trending Luohansi-Wayaoshang brittle-ductile fracture(F9),which retains the characteristics of multi-stage compression brittle-ductile structure from north to south,and the section develops tectonic slices,it controls the spatial location of mineralized alteration zone.The third level is F9 which controls the NWW-NW secondary derivative brittle-ductile shear zone,which is nearly parallel to it,and controls the spatial form of ore bodies.The fourth level is the position where the occurrence of shear zone changes and the extensional fracture zone,which controls the occurrence change of orebodies and the changes of ore grade and type,such as thickening and quartz vein type superimposition and enrichment.The main ore-controlling structure extends in the direction of nearly east-west and northwest-west.The orebody dips northward gently and steeply locally,and is controlled by the vertical schistosomiasis zone of northward dip.The space may be in the form of multiple folds or fold stacks.The main gold metallogenic bodies in this area formed hydrothermal alteration and enrichment in the process of brittle-ductile shear deformation in the late Indosinian period,superimposed by enrichment of gold-bearing quartz veins in the extensional fracture zone of shear zone.The metallogenic type is Late Triassic brittle-ductile shear zone superimposed extension fracture hydrothermal gold deposit.
引文
[1]张国伟，孟庆任，赖绍聪.秦岭造山带的结构构造[J].中国科学（B辑），1995,25(9):994-1003.Zhang Guowei,Meng Qingren,Lai Shaocong.Structures tectonic of the Qinling orogenic belt[J]. Chinese Science(B Series),1995,25(9):994-1003.
[2]张国伟，董云鹏，姚安平.秦岭造山带基本组成与结构及其构造演化[J].陕西地质，1997,15(2):1-14.Zhang Guowei,Dong Yunpeng,Yao Anping. The crustal compositions,structures and tectonic evolution of the Qinling orogenic belt[J]. Geology of Shaanxi,1997,15(2):1-14.
[3]王靖华，张复新，于在平，等.秦岭金属矿床成矿系列与大陆造山带构造动力学背景[J].中国地质，2002,29(2):192-196.Wang Jinghua,Zhang Fuxin,Yu Zaiping,et al. Minero genetic series of metallic ore deposits in the Qinling Mountains and tectonodynamic background of the continental orogenic belts[J].Geology in China,2002,29(2):192-196.
[4]董增产.凤县—两当地区北秦岭构造带地质组成及构造特征[D].西安：西北大学，2009.Dong Zengchan. The Tectonic Characteristics and Geological Formation of North Qinling Tectonic Belt in FengLiangdang County Region[D].Xi’an:Northwest University,2009.
[5]崔建堂，韩芳林，张拴厚，等.北秦岭罗汉寺岩群锆石SHRIMP U-Pb年龄及其构造地质意义[J].西北地质，2011,44(4):8-14.Cui Jiantang,Han Fanglin,Zhang Shuanhou,et al.North Qinling Luohansi rock group SHRIMP U-Pb zircon age and its tectonic significance[J]. Northwestern Geology,2011,44(4):8-14.
[6]李雄，李海平，陈隽璐.罗汉寺岩群地质特征、时代及意义[J].陕西地质，2003,21(2):57-61.Li Xiong,Li Haiping,Chen Juanlu. The geological characteristics,age and the significance of the Luohansi rock groups[J].Geology of Shaanxi,2003,21(2):57-61.
[7]闫臻.西秦岭晚古生代弧前盆地沉积与成矿作用[D].北京：中国科学院研究生院，2002.Yan Zhen. Sedimentation and Metallogenesis of Late Paleozoic Pre-arc Basin in West Qinling[D].Beijing:Graduate School of ChineseAcademy of Sciences,2002.
[8]胡长武.秦岭凤县老湾沟地区金矿找矿前景分析[J].低碳世界，2016(4):99-100.Hu Changwu. Prospect analysis of gold prospecting in Laowangou area,Feng County,Qinling[J].Low Carbon World,2016(4):99-100.
[9]涂怀奎.陕西凤县金矿类型与金的预富集及找矿方向[J].黄金地质，2001,7(1):73-78.Tu Huaikui. Gold deposit types,gold proenrichment and prospecting direction in Feng County of Shaanxi[J].Gold Geology,2001,7(1):73-78.
[10]杨朋涛，刘树文，李秋根，等.何家庄岩体的年龄和成因及其对南秦岭早三叠世构造演化的制约[J].中国科学（地球科学），2013,43(11):1874-1893.Yang Pengtao,Liu Shuwen,Li Qiugen,et al.Age and genesis of the Hejiazhuang pluton and its constraints on the early Triassic tectonic evolution of the south Qinling Mountains[J].Chinese Science(Geosciences),2013,43(11):1874-1893.
[11]陈安东，陈柏林，王永.陕西凤县马蹄沟金矿地区岩体与花岗斑岩LA-ICP-MS锆石U-Pb定年及地质意义[C]//中国地球科学联合学术年会论文集.北京：中国地球物理学会，2017:2.Chen Andong,Chen Bailin,Wang Yong.LA-ICP-MS zircon U-Pb dating and geological significance of the rock mass and granite porphyry in the gold deposit,Fengxian County,Shaanxi Province[C]//China Earth Science Joint Academic Annual Meeting Proceedings.Beijing:Chinese Geophysical Society,2017:2.
[12]杨新社.花岗斑岩对庞家河金矿的成矿意义探讨[J].世界有色金属，2017(6):174-175,177.Yang Xinshe.Discussion on the metallogenic significance of granite porphyry to Pangjiahe gold deposit[J]. World Nonferrous Metals,2017(6):174-175,177.
[13]翟裕生.矿田构造与成矿[M].北京：地质出版社，1981.Zhai Yusheng.Orefield Structure and Mineralization[M].Beijing:Geological Publishing House,1981.
[14]陈安东，陈柏林.陕西凤县马蹄沟金矿床控矿构造特征及其地质意义[J].地质论评，2016,61（增1):291-292.Chen Andong,Chen Bailin. Characteristics and geological significance of ore-controlling structure for the Matigou gold deposit in Fengxian,Shaanxi[J].Geological Review,2016,61(Supp.1):291-292.
[15]陈柏林，董法先，李中坚.韧性剪切带型金矿成矿模式[J].地质论评，1999,45(2):186-192.Chen Bailin,Dong Faxian,Li Zhongjian. Ore-forming model of ductile shear zone type gold deposits[J].Geological Review,1999,45(2):186-192.
[16]陈柏林.与韧性剪切带有关的不同金矿化类型地质地球化学特征对比研究[J].地质地球化学，2000,28(3):24-30.Chen Bailin. Comparison of geological and geochemical characteristics between gold deposits of different types related with ductile shear zones[J]. Geology-Geochemistry,2000,28(3):24-30.
[17]陈柏林.糜棱岩型金矿金元素丰度与构造变形的关系[J].矿床地质，2000,19(1):17-25.Chen Bailin.The relationship between gold abundance and structural deformation in altered mylonite type gold deposits[J].Mineral Deposits,2000,19(1):17-25.
[18]陈柏林，杨农，吴淦国，等.甘肃北山南带韧性剪切带型金矿床构造控矿解析[J].矿床地质，2002,21(2):149-158.Chen Bailin,Yang Nong,Wu Zhanguo,et al.Analysis of ore-controlling structure in ductile shear zone type gold deposits in southern Beishan area,Gansu Province[J].Mineral Deposits,2002,21(2):149-158.
[19]陈柏林.甘新北山金窝子韧性剪切带型金矿床成因[J].矿床地质，2010,29(6):972-982.Chen Bailin. A discussion on origin of Jinwozi ductile shear zone type gold deposit in Beishan area of Gansu and Xinjiang[J].Mineral Deposits,2010,29(6):972-982.
[20]刘方杰，孙勇，裴先治.八卦庙金矿床脆—韧性剪切构造及其控矿特征[J].西北大学学报（自然科学版），1999,29(6):569-574.Liu Fangjie,Sun Yong,Pei Xianzhi. On the ore controlling and characteristics of the britle-ductile shearing in the Baguamiao gold deposit in Fengxian County,Shaanxi Province[J]. Journal of Northwest University(Natural Science Edition),1999,29(6):569-574.
[21]王荣湖，刘志远，周乃武，等.含金剪切带型金矿床的成矿作用[J].地质与资源，2007,16(1):16-22.Wang Ronghu,Liu Zhiyuan,Zhou Naiwu,et al.Metallogenesis of auriferous shear zone type of gold deposits[J].Geology and Resources,2007,16(1):16-22.
[22]杨兴科，姬金生，张连昌，等.东天山大型韧性剪切带基本特征与金矿预测[J].大地构造与成矿学，1998,25(3):209-218.Yang Xingke,Ji Jinsheng,Zhang Lianchang,et al. Basic features and gold prognosis of the regional ductile shear zone in eastern Tianshan[J]. Geotectonica et Metallogenia,1998,25(3):209-218.
[23]杨兴科，陈强，张连昌.脆—韧性变形转换与动力成矿过程分析[J].地球学报，1999,20（增）：26-31.Yang Xingke,Chen Qiang,Zhang Lianchang.Analysis on brittle-ductile deformation transition and dynamo-metallogenesis process[J]. Acta Geoscientia Sinica,1999,20(Supp.):26-31.
[24]吴美德.含金剪切带型金矿床[J].黑龙江地质情报，1991(1):1-7.Wu Meide. Au-bearing shear zone type of gold deposits[J].Heilongjiang Geological Information,1991(1):1-7.
[2]张国伟，董云鹏，姚安平.秦岭造山带基本组成与结构及其构造演化[J].陕西地质，1997,15(2):1-14.Zhang Guowei,Dong Yunpeng,Yao Anping. The crustal compositions,structures and tectonic evolution of the Qinling orogenic belt[J]. Geology of Shaanxi,1997,15(2):1-14.
[3]王靖华，张复新，于在平，等.秦岭金属矿床成矿系列与大陆造山带构造动力学背景[J].中国地质，2002,29(2):192-196.Wang Jinghua,Zhang Fuxin,Yu Zaiping,et al. Minero genetic series of metallic ore deposits in the Qinling Mountains and tectonodynamic background of the continental orogenic belts[J].Geology in China,2002,29(2):192-196.
[4]董增产.凤县—两当地区北秦岭构造带地质组成及构造特征[D].西安：西北大学，2009.Dong Zengchan. The Tectonic Characteristics and Geological Formation of North Qinling Tectonic Belt in FengLiangdang County Region[D].Xi’an:Northwest University,2009.
[5]崔建堂，韩芳林，张拴厚，等.北秦岭罗汉寺岩群锆石SHRIMP U-Pb年龄及其构造地质意义[J].西北地质，2011,44(4):8-14.Cui Jiantang,Han Fanglin,Zhang Shuanhou,et al.North Qinling Luohansi rock group SHRIMP U-Pb zircon age and its tectonic significance[J]. Northwestern Geology,2011,44(4):8-14.
[6]李雄，李海平，陈隽璐.罗汉寺岩群地质特征、时代及意义[J].陕西地质，2003,21(2):57-61.Li Xiong,Li Haiping,Chen Juanlu. The geological characteristics,age and the significance of the Luohansi rock groups[J].Geology of Shaanxi,2003,21(2):57-61.
[7]闫臻.西秦岭晚古生代弧前盆地沉积与成矿作用[D].北京：中国科学院研究生院，2002.Yan Zhen. Sedimentation and Metallogenesis of Late Paleozoic Pre-arc Basin in West Qinling[D].Beijing:Graduate School of ChineseAcademy of Sciences,2002.
[8]胡长武.秦岭凤县老湾沟地区金矿找矿前景分析[J].低碳世界，2016(4):99-100.Hu Changwu. Prospect analysis of gold prospecting in Laowangou area,Feng County,Qinling[J].Low Carbon World,2016(4):99-100.
[9]涂怀奎.陕西凤县金矿类型与金的预富集及找矿方向[J].黄金地质，2001,7(1):73-78.Tu Huaikui. Gold deposit types,gold proenrichment and prospecting direction in Feng County of Shaanxi[J].Gold Geology,2001,7(1):73-78.
[10]杨朋涛，刘树文，李秋根，等.何家庄岩体的年龄和成因及其对南秦岭早三叠世构造演化的制约[J].中国科学（地球科学），2013,43(11):1874-1893.Yang Pengtao,Liu Shuwen,Li Qiugen,et al.Age and genesis of the Hejiazhuang pluton and its constraints on the early Triassic tectonic evolution of the south Qinling Mountains[J].Chinese Science(Geosciences),2013,43(11):1874-1893.
[11]陈安东，陈柏林，王永.陕西凤县马蹄沟金矿地区岩体与花岗斑岩LA-ICP-MS锆石U-Pb定年及地质意义[C]//中国地球科学联合学术年会论文集.北京：中国地球物理学会，2017:2.Chen Andong,Chen Bailin,Wang Yong.LA-ICP-MS zircon U-Pb dating and geological significance of the rock mass and granite porphyry in the gold deposit,Fengxian County,Shaanxi Province[C]//China Earth Science Joint Academic Annual Meeting Proceedings.Beijing:Chinese Geophysical Society,2017:2.
[12]杨新社.花岗斑岩对庞家河金矿的成矿意义探讨[J].世界有色金属，2017(6):174-175,177.Yang Xinshe.Discussion on the metallogenic significance of granite porphyry to Pangjiahe gold deposit[J]. World Nonferrous Metals,2017(6):174-175,177.
[13]翟裕生.矿田构造与成矿[M].北京：地质出版社，1981.Zhai Yusheng.Orefield Structure and Mineralization[M].Beijing:Geological Publishing House,1981.
[14]陈安东，陈柏林.陕西凤县马蹄沟金矿床控矿构造特征及其地质意义[J].地质论评，2016,61（增1):291-292.Chen Andong,Chen Bailin. Characteristics and geological significance of ore-controlling structure for the Matigou gold deposit in Fengxian,Shaanxi[J].Geological Review,2016,61(Supp.1):291-292.
[15]陈柏林，董法先，李中坚.韧性剪切带型金矿成矿模式[J].地质论评，1999,45(2):186-192.Chen Bailin,Dong Faxian,Li Zhongjian. Ore-forming model of ductile shear zone type gold deposits[J].Geological Review,1999,45(2):186-192.
[16]陈柏林.与韧性剪切带有关的不同金矿化类型地质地球化学特征对比研究[J].地质地球化学，2000,28(3):24-30.Chen Bailin. Comparison of geological and geochemical characteristics between gold deposits of different types related with ductile shear zones[J]. Geology-Geochemistry,2000,28(3):24-30.
[17]陈柏林.糜棱岩型金矿金元素丰度与构造变形的关系[J].矿床地质，2000,19(1):17-25.Chen Bailin.The relationship between gold abundance and structural deformation in altered mylonite type gold deposits[J].Mineral Deposits,2000,19(1):17-25.
[18]陈柏林，杨农，吴淦国，等.甘肃北山南带韧性剪切带型金矿床构造控矿解析[J].矿床地质，2002,21(2):149-158.Chen Bailin,Yang Nong,Wu Zhanguo,et al.Analysis of ore-controlling structure in ductile shear zone type gold deposits in southern Beishan area,Gansu Province[J].Mineral Deposits,2002,21(2):149-158.
[19]陈柏林.甘新北山金窝子韧性剪切带型金矿床成因[J].矿床地质，2010,29(6):972-982.Chen Bailin. A discussion on origin of Jinwozi ductile shear zone type gold deposit in Beishan area of Gansu and Xinjiang[J].Mineral Deposits,2010,29(6):972-982.
[20]刘方杰，孙勇，裴先治.八卦庙金矿床脆—韧性剪切构造及其控矿特征[J].西北大学学报（自然科学版），1999,29(6):569-574.Liu Fangjie,Sun Yong,Pei Xianzhi. On the ore controlling and characteristics of the britle-ductile shearing in the Baguamiao gold deposit in Fengxian County,Shaanxi Province[J]. Journal of Northwest University(Natural Science Edition),1999,29(6):569-574.
[21]王荣湖，刘志远，周乃武，等.含金剪切带型金矿床的成矿作用[J].地质与资源，2007,16(1):16-22.Wang Ronghu,Liu Zhiyuan,Zhou Naiwu,et al.Metallogenesis of auriferous shear zone type of gold deposits[J].Geology and Resources,2007,16(1):16-22.
[22]杨兴科，姬金生，张连昌，等.东天山大型韧性剪切带基本特征与金矿预测[J].大地构造与成矿学，1998,25(3):209-218.Yang Xingke,Ji Jinsheng,Zhang Lianchang,et al. Basic features and gold prognosis of the regional ductile shear zone in eastern Tianshan[J]. Geotectonica et Metallogenia,1998,25(3):209-218.
[23]杨兴科，陈强，张连昌.脆—韧性变形转换与动力成矿过程分析[J].地球学报，1999,20（增）：26-31.Yang Xingke,Chen Qiang,Zhang Lianchang.Analysis on brittle-ductile deformation transition and dynamo-metallogenesis process[J]. Acta Geoscientia Sinica,1999,20(Supp.):26-31.
[24]吴美德.含金剪切带型金矿床[J].黑龙江地质情报，1991(1):1-7.Wu Meide. Au-bearing shear zone type of gold deposits[J].Heilongjiang Geological Information,1991(1):1-7.
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