江西金山金矿控矿韧性剪切带的递进变形成矿机理:显微构造证据
摘要
在对江西金山金矿控矿韧性剪切带内岩石和矿石的显微构造分析基础上,对剪切带的递进变形与成矿机理进行探讨。研究发现,金山韧性剪切带在韧性—韧脆性递进剪切变形过程中发育3类石英脉透镜体或石香肠构造;剪切压溶和缝合线构造在金山韧性剪切带内强烈发育;扩散蠕变机制是金山韧性剪切带重要的变形机制。大量缝合线构造的形成增强了岩石的孔隙度和渗透率,有利于流体的迁移和沉淀。金山剪切带内变形和成矿作用经历了漫长复杂的地质过程,粗略估算至少跨过了72 Ma。在递进剪切变形过程中经历多种构造变形机制,如经历了以透入性片理为代表的韧性剪切变形机制到以"次级剪切面"构造网络为代表的韧-脆性剪切变形机制的转换。剪切带的递进剪切变形自始至终控制着金的成矿作用过程,没有递进剪切变形也就没有金山金矿的形成。
Microscopic deformation structures observed in deformed rocks and ores from Jinshan auriferous ductile shear zone of Jinshan gold deposit,Jiangxi Province,are examined and analyzed.Gold mineralization process during progressive shear deformation in the ductile shear zone is discussed.Three classes of quartz-vein boudinage are found developed within the ductile shear zone with respect to vein and boudinage characteristics and timing of major-phase mineralization.The discovery covers intensive pressure solution and pressure dissolution structures of stylolites or dissolution seams developed in the ductile shear zone in detail.The extensively and intensively developed stylolites help enhance porosity and permeability of the shear zone rocks,and provide pathways for migration of fluids as well as space for silica precipitation.Their presence indicates that fluids-enhanced diffusion creep or diffusional mass transfer is not only an important deformation mechanism but also a critical component of mineralization mechanism for Jinshan auriferous ductile shear zone.The paper estimates a minimum 72 million years span for the progressive deformation and mineralization process associated with multiple deformation mechanisms,and underwent a significant deformation regime transfer from penetrative schistosity-dominated fabric of ductile deformation to a non-penetrative(at outcrop and microscopic scales) network of "second-order" shear structures of ductile-brittle deformation.It is concluded that the mineralization process was caused by the progressive shear,and that there would be no such a large gold deposit without the prolonged progressive deformation.
Microscopic deformation structures observed in deformed rocks and ores from Jinshan auriferous ductile shear zone of Jinshan gold deposit,Jiangxi Province,are examined and analyzed.Gold mineralization process during progressive shear deformation in the ductile shear zone is discussed.Three classes of quartz-vein boudinage are found developed within the ductile shear zone with respect to vein and boudinage characteristics and timing of major-phase mineralization.The discovery covers intensive pressure solution and pressure dissolution structures of stylolites or dissolution seams developed in the ductile shear zone in detail.The extensively and intensively developed stylolites help enhance porosity and permeability of the shear zone rocks,and provide pathways for migration of fluids as well as space for silica precipitation.Their presence indicates that fluids-enhanced diffusion creep or diffusional mass transfer is not only an important deformation mechanism but also a critical component of mineralization mechanism for Jinshan auriferous ductile shear zone.The paper estimates a minimum 72 million years span for the progressive deformation and mineralization process associated with multiple deformation mechanisms,and underwent a significant deformation regime transfer from penetrative schistosity-dominated fabric of ductile deformation to a non-penetrative(at outcrop and microscopic scales) network of "second-order" shear structures of ductile-brittle deformation.It is concluded that the mineralization process was caused by the progressive shear,and that there would be no such a large gold deposit without the prolonged progressive deformation.
引文
[1]孙承辕,张金春.江西金山金矿韧性剪切过程中物质的迁移[J].矿床地质,1994,13(4):371-379.
[2]季俊峰,孙承辕,郑晴.江西金山剪切带型金矿床中含金石英脉的成矿特征[J].地质论评,1994,40(4):361-367.
[3]季峻峰,刘英俊,孙承辕,等.江西金山剪切带型金矿床两类矿石的地球化学特征兼论两阶段成矿机制[J].地球化学,1994(3):226-232.
[4]韦星林.江西金山韧性剪切带型金矿地质特征[J].江西地质,1996,10(1):52-64.
[5]华仁民,李晓峰,张开平,等.江西金山金矿成矿过程流体作用地球化学[J].南京大学学报:自然科学版,2002,38(3):408-417.
[6]李晓峰,华仁民,毛景文.江西金山金矿物质来源的铂族元素证据[J].地质与勘探,2002,38(6):13-16.
[7]李晓峰,易先奎,朱和平.德兴金山金矿床成矿流体来源:小尺度构造和同位素地球化学证据[J].矿床地质,2009,28(1):42-52.
[8]曾键年,林卫兵,范永香.江西金山金矿床成矿地球化学特征[J].地质地球化学,2002,30(4):26-33.
[9]刘志远,金成洙,王荣湖.江西金山金矿床流体包裹体地球化学特征[J].矿产与地质,2005,19(2):127-133.
[10]毛光周,华仁民,高剑峰,等.江西金山金矿床含金黄铁矿的稀土元素和微量元素特征[J].矿床地质,2006,25(4):412-426.
[11]朱恺军,范宏瑞.金山金矿的地质特征和形成条件[J].地质找矿论丛,1991,6(2):177-185.
[12]万昌林.试论金山金矿成矿特征与成矿控制[J].江西地质,1997,11(3):1-6.
[13]曾键年,范永香,谭铁龙.江西金山金矿床构造控矿特征[J].地质与勘探,1998,34(1):1-6.
[14]梁毓鎏.江西金山金矿床构造控矿特征[J].黄金,2001,22(6):6-8.
[15]肖勇.金山金矿田脆-韧性剪切带与成矿模式[J].矿产与地质,2001,15(S):424-430.
[16]易先奎.江西金山金矿床成矿远景分析[J].矿产与地质,2003,17(S):420-422.
[17]李晓峰,王春增,易先奎,等.德兴金山金矿田不同尺度构造特征及其与成矿作用的关系[J].地质论评,2007,53(6):774-782.
[18]舒良树,施央申,郭令智,等.江南中段板块-地体构造与碰撞造山运动学[M].南京:南京大学出版社,1995:1-174.
[19]Wang Xiao-lei,Zhao Guo-chun,Zhou Jin-cheng,et al.Geochronology and Hf isotopes of zircon from volcanic rocksof the Shuangqiaoshan Group,South China:Implications forthe Neoproterozoic tectonic evolution of the eastern Jiangnanorogen[J].Gondwana Research,2008,14(3):355-367.
[20]van de Kamp P C.Smectite-illite-muscovite transformations,quartz dissolution,and silica release in shales[J].Claysand Clay Minerals,2008,56(1):66-81.
[21]江西有色地质研究所.德兴-乐平成矿带成矿规律成矿预测研究报告[R].南昌:江西有色地质勘查局,1989.
[22]Ramsay J G.The crack-seal mechanism of rock deformation[J].Nature,1980,284:135-139.
[23]Sibson R H,Robert F,Poulsen K H.High-angle reversefaults,fluid pressure cycling and mesothermal gold quartzdeposits[J].Geology,1988,16:551-555.
[24]Boullier AM,Robert F.Palaeoseismic events recorded in Ar-chaean gold quartz vein networks,Val d′Or,Abitibi,Quebec,Canada[J].Journal of Structural Geology,1992,14:161-179.
[25]Cox S F.Faulting processes at high fluid pressures:An ex-ample of fault-valve behavior from the Wattle Gully Fault,Victoria,Australia[J].Journal of Geophysical Research,1995,100:841-859.
[26]Robert F,Boullier A M,Firdaous K.Gold quartz veins inmetamorphic terranes and their bearing on the role of fluids infaulting[J].Journal of Geophysical Research,1995,100:12861-12879.
[27]Nguyen P T,Cox S F,Harris L B,et al.Fault-valve be-havior in optimally oriented shear zones:An example at theRevenge gold mine,Kambalda,Western Australia[J].Journal of Structural Geology,1998,20:1625-1640.
[28]Sibson R H.Seismogenic framework for hydrothermal trans-port and ore deposition[C]//Richards J P,Tosdal R M.Structural Controls on Ore Genesis 14 Reviews in EconomicGeology,2001,25-50.
[29]Kolb J,Rogers A,MeyerFM,etal.Dominantcoaxial de-formation of veins during the interseismic stage of the fault-valve cycle:Microfabrics of laminated quartz veins of theHutti gold mine,India[J].Journal of Structural Geology,2005,27:2043-2057.
[30]梁金城,李石锦,易诗军.湘西沃溪金矿床层状石英脉的显微构造与组构初探[J].桂林冶金地质学院学报,1981(3):41-51.
[31]刘英俊,沙鹏,朱恺军.江西德兴地区中元古界双桥山群含金建造的地球化学研究[J].桂林冶金地质学院学报,1989,9(2):115-125.
[32]朱恺军,范宏瑞.金山金矿的地质特征和形成条件[J].地质找矿论丛,1991,6(2):177-185.
[33]朱恺军,范宏瑞.江西金山金矿床层控成因的地质地球化学证据[J].地质找矿论丛,1991,6(4):18-27.
[34]张金春.江西金山韧性剪切带型金矿成矿地球化学研究[D].南京:南京大学,1994.
[35]黄宏立,杨文思.赣东北金山金矿床的地质特征及矿床成因[J].地质找矿论丛,1990,5(2):29-39.
[36]王秀璋,单强,梁华英,等.金山金矿床成矿时代及矿床成因[J].地球化学,1999,28(1):10-17.
[37]李晓峰,华仁民,杨凤根,等.金山金矿K-Ar年龄及其对赣东北构造演化的指示意义[J].岩石矿物学杂志,2002,21(1):49-54.
[38]毛光周,华仁民,龙光明,等.江西金山金矿成矿时代探讨——来自石英流体包裹体Rb-Sr年龄的证据[J].地质学报,2008,82(4):532-539.
[39]伍勤生,刘青莲.金山成矿年龄测定及矿床成因探讨[C]//第四届全国同位素地质年代和同位素地球化学讨论会论文(摘要)汇编.1989.
[2]季俊峰,孙承辕,郑晴.江西金山剪切带型金矿床中含金石英脉的成矿特征[J].地质论评,1994,40(4):361-367.
[3]季峻峰,刘英俊,孙承辕,等.江西金山剪切带型金矿床两类矿石的地球化学特征兼论两阶段成矿机制[J].地球化学,1994(3):226-232.
[4]韦星林.江西金山韧性剪切带型金矿地质特征[J].江西地质,1996,10(1):52-64.
[5]华仁民,李晓峰,张开平,等.江西金山金矿成矿过程流体作用地球化学[J].南京大学学报:自然科学版,2002,38(3):408-417.
[6]李晓峰,华仁民,毛景文.江西金山金矿物质来源的铂族元素证据[J].地质与勘探,2002,38(6):13-16.
[7]李晓峰,易先奎,朱和平.德兴金山金矿床成矿流体来源:小尺度构造和同位素地球化学证据[J].矿床地质,2009,28(1):42-52.
[8]曾键年,林卫兵,范永香.江西金山金矿床成矿地球化学特征[J].地质地球化学,2002,30(4):26-33.
[9]刘志远,金成洙,王荣湖.江西金山金矿床流体包裹体地球化学特征[J].矿产与地质,2005,19(2):127-133.
[10]毛光周,华仁民,高剑峰,等.江西金山金矿床含金黄铁矿的稀土元素和微量元素特征[J].矿床地质,2006,25(4):412-426.
[11]朱恺军,范宏瑞.金山金矿的地质特征和形成条件[J].地质找矿论丛,1991,6(2):177-185.
[12]万昌林.试论金山金矿成矿特征与成矿控制[J].江西地质,1997,11(3):1-6.
[13]曾键年,范永香,谭铁龙.江西金山金矿床构造控矿特征[J].地质与勘探,1998,34(1):1-6.
[14]梁毓鎏.江西金山金矿床构造控矿特征[J].黄金,2001,22(6):6-8.
[15]肖勇.金山金矿田脆-韧性剪切带与成矿模式[J].矿产与地质,2001,15(S):424-430.
[16]易先奎.江西金山金矿床成矿远景分析[J].矿产与地质,2003,17(S):420-422.
[17]李晓峰,王春增,易先奎,等.德兴金山金矿田不同尺度构造特征及其与成矿作用的关系[J].地质论评,2007,53(6):774-782.
[18]舒良树,施央申,郭令智,等.江南中段板块-地体构造与碰撞造山运动学[M].南京:南京大学出版社,1995:1-174.
[19]Wang Xiao-lei,Zhao Guo-chun,Zhou Jin-cheng,et al.Geochronology and Hf isotopes of zircon from volcanic rocksof the Shuangqiaoshan Group,South China:Implications forthe Neoproterozoic tectonic evolution of the eastern Jiangnanorogen[J].Gondwana Research,2008,14(3):355-367.
[20]van de Kamp P C.Smectite-illite-muscovite transformations,quartz dissolution,and silica release in shales[J].Claysand Clay Minerals,2008,56(1):66-81.
[21]江西有色地质研究所.德兴-乐平成矿带成矿规律成矿预测研究报告[R].南昌:江西有色地质勘查局,1989.
[22]Ramsay J G.The crack-seal mechanism of rock deformation[J].Nature,1980,284:135-139.
[23]Sibson R H,Robert F,Poulsen K H.High-angle reversefaults,fluid pressure cycling and mesothermal gold quartzdeposits[J].Geology,1988,16:551-555.
[24]Boullier AM,Robert F.Palaeoseismic events recorded in Ar-chaean gold quartz vein networks,Val d′Or,Abitibi,Quebec,Canada[J].Journal of Structural Geology,1992,14:161-179.
[25]Cox S F.Faulting processes at high fluid pressures:An ex-ample of fault-valve behavior from the Wattle Gully Fault,Victoria,Australia[J].Journal of Geophysical Research,1995,100:841-859.
[26]Robert F,Boullier A M,Firdaous K.Gold quartz veins inmetamorphic terranes and their bearing on the role of fluids infaulting[J].Journal of Geophysical Research,1995,100:12861-12879.
[27]Nguyen P T,Cox S F,Harris L B,et al.Fault-valve be-havior in optimally oriented shear zones:An example at theRevenge gold mine,Kambalda,Western Australia[J].Journal of Structural Geology,1998,20:1625-1640.
[28]Sibson R H.Seismogenic framework for hydrothermal trans-port and ore deposition[C]//Richards J P,Tosdal R M.Structural Controls on Ore Genesis 14 Reviews in EconomicGeology,2001,25-50.
[29]Kolb J,Rogers A,MeyerFM,etal.Dominantcoaxial de-formation of veins during the interseismic stage of the fault-valve cycle:Microfabrics of laminated quartz veins of theHutti gold mine,India[J].Journal of Structural Geology,2005,27:2043-2057.
[30]梁金城,李石锦,易诗军.湘西沃溪金矿床层状石英脉的显微构造与组构初探[J].桂林冶金地质学院学报,1981(3):41-51.
[31]刘英俊,沙鹏,朱恺军.江西德兴地区中元古界双桥山群含金建造的地球化学研究[J].桂林冶金地质学院学报,1989,9(2):115-125.
[32]朱恺军,范宏瑞.金山金矿的地质特征和形成条件[J].地质找矿论丛,1991,6(2):177-185.
[33]朱恺军,范宏瑞.江西金山金矿床层控成因的地质地球化学证据[J].地质找矿论丛,1991,6(4):18-27.
[34]张金春.江西金山韧性剪切带型金矿成矿地球化学研究[D].南京:南京大学,1994.
[35]黄宏立,杨文思.赣东北金山金矿床的地质特征及矿床成因[J].地质找矿论丛,1990,5(2):29-39.
[36]王秀璋,单强,梁华英,等.金山金矿床成矿时代及矿床成因[J].地球化学,1999,28(1):10-17.
[37]李晓峰,华仁民,杨凤根,等.金山金矿K-Ar年龄及其对赣东北构造演化的指示意义[J].岩石矿物学杂志,2002,21(1):49-54.
[38]毛光周,华仁民,龙光明,等.江西金山金矿成矿时代探讨——来自石英流体包裹体Rb-Sr年龄的证据[J].地质学报,2008,82(4):532-539.
[39]伍勤生,刘青莲.金山成矿年龄测定及矿床成因探讨[C]//第四届全国同位素地质年代和同位素地球化学讨论会论文(摘要)汇编.1989.
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