安第斯与冈底斯成矿带斑岩铜矿床矿物学和成矿斑岩地球化学特征对比
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摘要
在总结安第斯和冈底斯斑岩铜矿床地质矿物学特征的基础上,通过对2个成矿带与斑岩铜矿床有关的岩浆岩地球化学特征的对比分析,探讨了2种构造环境下形成的斑岩铜矿床含矿斑岩与成矿过程的异同点。安第斯成矿带的斑岩铜矿床形成于洋壳俯冲陆缘弧环境,成矿时代主要集中在始新世晚期—渐新世(43~31Ma)和中新世中期—上新世(12~4Ma),金属组合包括Cu-Mo和Cu-Au,含矿斑岩的SiO_2含量变化范围较大,岩性从中性到酸性,以钙碱性-高钾钙碱性系列为主,少部分具有典型埃达克岩地球化学特征,而大多数安第斯含矿斑岩具有正常岛弧系列火山岩的地球化学特征。冈底斯成矿带斑岩铜矿床主要发育于陆-陆碰撞环境,成矿时代为中新世(20~12Ma),金属组合为Cu-Mo,缺乏Cu-Au组合,含矿斑岩岩性以酸性为主,且主要为高钾钙碱性-钾玄质系列岩浆岩,具有典型埃达克岩的地球化学特征。安第斯成矿带含矿斑岩的形成很可能是板片释放流体交代楔形地幔,经部分熔融与MASH过程的产物,并不是直接源于洋壳的部分熔融;而冈底斯成矿带含矿斑岩成因可能是早期洋壳多次俯冲形成俯冲增生弧,之后在陆陆碰撞过程中经历缩短加厚,与深部构造动力学机制发生变化时的部分熔融有关。
In this paper, the authors analyzed and compared the geochemical characteristics of the magmatites related to porphyry copper deposits between the Andean and Gangdise metallogenic belts based on the summarizing of the geological mineralogical differences of both the ore-bearing porphyries and the mineralization mechanisms between the porphyry copper ores formed in two different tectonic backgrounds. The porphyry copper deposits in the Andean metallogenic belt were developed during the subduction process of oceanic crust, and they were mainly formed in the late Eocene-Oligocene(43~31 Ma) and the middle Miocene-Pliocene(12~4 Ma). Their metal combinations include Cu-Mo and Cu-Au. The components of SiO_2 in the ore-baring porphyries vary in a large range, and the lithologies of these porphyries change from intermediate to acidic, dominated by the series of calcium alkaline-highpotassium calcium alkaline rocks. Only a small part of the ore-bearing porphyries has typical adakite geochemical characteristics,whereas most of ore-bearing porphyries in the Andean metallogenic belt have the volcanic rock geochemical characteristics of normal arc series. The porphyry copper deposits in the Gangdise metallogenic belt were mainly developed during the continental collision process, and they were mainly formed in the Miocene(20~12 Ma). Their metal combination is Cu-Mo with the lack of the combination of Cu-Au. The lithologies of ore-bearing poryphries are mainly acid, the poryphyries are dominated by magmatic rocks with high potassium calcium alkali, and the ore-bearing porphyries have typical adakite geochemical characteristics. The ore-bearing porphyries in the Andean metallogenic belt might have been formed during the partial melting process of the wedge mantle material metasomatized by the fluid which was released from the crust plate and the MASH procedure. They were not developed directly from the partial melted oceanic crust. The ore-bearing porphyries in the Gangdise metallogenic belt might have been formed during the partial melting process of the subduction accretion arc with the change of deep tectonic dynamic mechanism, which was caused by the multi-subduction of ocean crust and was shortened and thickened during the continental collision process.
In this paper, the authors analyzed and compared the geochemical characteristics of the magmatites related to porphyry copper deposits between the Andean and Gangdise metallogenic belts based on the summarizing of the geological mineralogical differences of both the ore-bearing porphyries and the mineralization mechanisms between the porphyry copper ores formed in two different tectonic backgrounds. The porphyry copper deposits in the Andean metallogenic belt were developed during the subduction process of oceanic crust, and they were mainly formed in the late Eocene-Oligocene(43~31 Ma) and the middle Miocene-Pliocene(12~4 Ma). Their metal combinations include Cu-Mo and Cu-Au. The components of SiO_2 in the ore-baring porphyries vary in a large range, and the lithologies of these porphyries change from intermediate to acidic, dominated by the series of calcium alkaline-highpotassium calcium alkaline rocks. Only a small part of the ore-bearing porphyries has typical adakite geochemical characteristics,whereas most of ore-bearing porphyries in the Andean metallogenic belt have the volcanic rock geochemical characteristics of normal arc series. The porphyry copper deposits in the Gangdise metallogenic belt were mainly developed during the continental collision process, and they were mainly formed in the Miocene(20~12 Ma). Their metal combination is Cu-Mo with the lack of the combination of Cu-Au. The lithologies of ore-bearing poryphries are mainly acid, the poryphyries are dominated by magmatic rocks with high potassium calcium alkali, and the ore-bearing porphyries have typical adakite geochemical characteristics. The ore-bearing porphyries in the Andean metallogenic belt might have been formed during the partial melting process of the wedge mantle material metasomatized by the fluid which was released from the crust plate and the MASH procedure. They were not developed directly from the partial melted oceanic crust. The ore-bearing porphyries in the Gangdise metallogenic belt might have been formed during the partial melting process of the subduction accretion arc with the change of deep tectonic dynamic mechanism, which was caused by the multi-subduction of ocean crust and was shortened and thickened during the continental collision process.
引文
[1]芮宗瑶,李光明,张立生,等.西藏斑岩铜矿对重大地质事件的响应[J].地学前缘,2004,11(1):145-152.
[2]芮宗瑶,侯增谦,李光明,等.冈底斯斑岩铜矿成矿模式[J].地质论评,2006,52:459-466.
[3]杨志明,侯增谦,江迎飞,等.西藏驱龙矿区早侏罗世斑岩的Sr-NdPb及锆石Hf同位素研究[J].岩石学报,2011,27(7):2003-2010.
[4]卢民杰,朱小三,郭维民.南美安第斯地区成矿区带划分探讨[J].矿床地质,2016,35(5):1073-1083.
[5]Moreno T,Gibbons W.The geology of Chile[M].London:Geological Society of London.2007:211-232.
[6]Singer D A,Berger V I,Menzie W D,et al.Porphyry copper deposit density[J].Economic Geology,2005,100:491-514.
[7]Sillitoe R H.A plate tectonic model for the origin of porphyry copper deposits[J].Economic Geology,1972,67:184-197.
[8]侯增谦,曲晓明,黄卫,等.冈底斯斑岩铜矿成矿带有望成为西藏第二条“玉龙”铜矿带[J].中国地质,2001,28(10):27-30.
[9]侯增谦,高永丰,孟祥金,等.西藏冈底斯中新世斑岩铜矿带:埃达克质斑岩成因与构造控制[J].岩石学报,2004,20(2):239-248.
[10]曲晓明,侯增谦,黄卫.冈底斯斑岩铜矿(化)带:西藏的第二条玉龙铜矿带?[J].矿床地质,2001,20:355-366.
[11]Chung S L,Chu M F,Ji J Q,et al.The nature and timing of crustal thickening in Southern Tibet[J].Tectonophysics,2009,477:36-48.
[12]Dong G,Mo X,Zhao Z,et al.Geochronologic constraints on the magmatic underplating of the Gangdese Belt in the India-Eurasia collision:evidence of SHRIMPⅡzircon U-P bdating[J].Acta Geologica Sinica,2005,79:787-794.
[13]侯增谦,杨竹森,徐文艺,等.青藏高原碰撞造山带:Ⅰ.主碰撞造山成矿作用[J].矿床地质,2006,25:337-358.
[14]侯增谦,潘桂棠,王安建,等.青藏高原碰撞造山带:Ⅱ.晚碰撞转换成矿作用[J].矿床地质.2006,25(5):521-543.
[15]侯增谦,曲晓明,杨竹森,等.青藏高原碰撞造山带:Ⅲ.后碰撞伸展成矿作用[J].矿床地质,2006,25(6):629-651.
[16]杨志明,侯增谦,宋玉财,等.西藏驱龙超大型斑岩铜矿床:地质、蚀变与矿化[J].矿床地质,2008,27:279-318.
[17]孟祥金,侯增谦,高永丰,等.碰撞造山型斑岩铜矿蚀变分带模式--以西藏冈底斯斑岩铜矿带为例[J].地学前缘,2004,11(1):201-214.
[18]Camus F.The Andean porphyry systems[M].University of Tasmania,Centre for Ore Deposit Research Special Publication.2002,4:5-22.
[19]Deckart K,Silva W,Spr?hnle C,et al.Timing and duration of hydrothermal activity at the Los Bronces porphyry cluster:an update[J].Mineralium Deposita,2014,49(5):535-546.
[20]Schwartz M O.The porphyry copper deposit at La Granja,Peru[J].Economic Geology,1982,77:482-487.
[21]Camus F.The Andean porphyry systems[C]//Porter T M.Super porphyry copper and gold deposits:A global perspective.Linden Park,South Australia,Porter Geo Consultancy Publishing,2005:1-26.
[22]Barra F,Alcota H,Rivera S,et al.Timing and formation of porphyry Cu-Mo mineralization in the Chuquicamata district,northern Chile:new constraints from the Toki cluster[J].Mineralium Deposita,2013,48(5):629-651.
[23]郎兴海,唐菊兴,李志军,等.西藏冈底斯斑岩铜矿带雄村矿区侏罗纪成矿作用:来自锆石U-Pb和辉钼矿Re-Os年龄的证据[J].矿物学报,2013,S2:328.
[24]Hou Z Q,Gao Y F,Qu X M,et al.Origin of adakiticintrusives generated during mid-Miocene east-west extension in southern Tibet[J].Earth and Planetary Science Letters,2004,220:139-155.
[25]Yang Z M,Hou Z Q,White N C,et al.Geology of the post-collisional porphyry copper-molybdenum deposit at Qulong,Tibet[J].Ore Geology Review,2009,36:133-159.
[26]Chung S L,Liu D,Ji J,et al.Adakites from continental collision zones:melting of thickened lower crust beneath southern Tibet[J].Geology,2003,31:1021-1024.
[27]Xu W C,Zhang H F,Guo L,et al.Miocene high Sr/Y magmatism,south Tibet:Product of partial melting of subducted Indian continental crust and its tectonic implication[J].Lithos,2010,114:293-306.
[28]郑有业,高顺宝,程力军,等.西藏冲江大型斑岩铜(钼金)矿床的发现及意义[J].中国地质大学学报(地球科学版),2004,29(3):333-339.
[29]周维德,张正伟,袁盛朝,等.西藏尼木县白容斑岩型铜钼矿床特征及成矿期次[J].矿物岩石地球化学通报,2014,33(2):177-184.
[30]周玉,温春齐,周雄,等.西藏邦浦钼铜多金属矿床稀土元素特征[J].矿物学报,2009,增刊:363-364.
[31]周雄,温春齐,费光春,等.西藏邦铺斑岩型钼矿床二长花岗斑岩地球化学特征及构造意义[J].矿物岩石,2010,30(4):48-54.
[32]杨志明.西藏驱龙超大型斑岩铜矿床--岩浆作用及矿床成因[D].中国地质科学院博士学位论文,2008:1-145.
[33]Mo X X,Dong G C,Zhao Z D,et al.Timing of magma mixing in Gangdise magmatic belt during the India-Asia collision:zirconSHIRMP U-Pb dating[J].Acta Geologica Sinica,2005,79(1):66-76.
[34]赵志丹,莫宣学,Nomade S,等.青藏高原拉萨地块碰撞后超钾质岩石的时空分布及其意义[J].岩石学报,2006,22:787-794.
[35]Gao Y F,Hou Z Q,Wei R H.Post-collisional adakitic porphyries in Tibet:Geochemical and Sr-Nd-Pb isotopic constrains on partial melting of oceanic lithosphere and crust-mantle interaction[J].Acta Geologica Sinica,2003,77:123-135.
[36]Richards P J,Kerrich R.Adakite-like rocks:their diverse origins and questionable role in metallogenesis[J].Economic Geology,2007,102(4):537-576.
[37]Qu X M,Hou Z Q,Li Y G.Melt components derived from a subducted slab in late orogenic ore-bearing porphyries in the Gangdese copper belt,southern Tibetan plateau[J].Lithos,2004,74:131-148.
[38]Guo Z F,Wilson M,Liu J Q.Post-collisional adakites in south Tibet:Products of partial melting of subduction-modified lower crust[J].Lithos,2007,96:205-224.
[39]Gao Y F,Hou Z Q,Kamber B S,et al.Adakite-like porphyries from the southern Tibetan continental collision zones:evidence for slab meltmetasomatism[J].Contribution to Mineral Petrology,2007,153:105-120.
[40]Willett S D,Beaumont C.Subduction of Asian lithospheric mantle beneath Tibet inferred from models of continental collison[J].Nature,1994,369:642-645.
[41]Hou Z Q,Zhang H R,Pan X F,et al.Porphyry Cu(-Mo-Au)deposits related to melting of thickened mafic lower crust:Examples from the eastern Tethyanmetallogenic domain[J].Ore Geology Reviews,2011,39:21-45.
[2]芮宗瑶,侯增谦,李光明,等.冈底斯斑岩铜矿成矿模式[J].地质论评,2006,52:459-466.
[3]杨志明,侯增谦,江迎飞,等.西藏驱龙矿区早侏罗世斑岩的Sr-NdPb及锆石Hf同位素研究[J].岩石学报,2011,27(7):2003-2010.
[4]卢民杰,朱小三,郭维民.南美安第斯地区成矿区带划分探讨[J].矿床地质,2016,35(5):1073-1083.
[5]Moreno T,Gibbons W.The geology of Chile[M].London:Geological Society of London.2007:211-232.
[6]Singer D A,Berger V I,Menzie W D,et al.Porphyry copper deposit density[J].Economic Geology,2005,100:491-514.
[7]Sillitoe R H.A plate tectonic model for the origin of porphyry copper deposits[J].Economic Geology,1972,67:184-197.
[8]侯增谦,曲晓明,黄卫,等.冈底斯斑岩铜矿成矿带有望成为西藏第二条“玉龙”铜矿带[J].中国地质,2001,28(10):27-30.
[9]侯增谦,高永丰,孟祥金,等.西藏冈底斯中新世斑岩铜矿带:埃达克质斑岩成因与构造控制[J].岩石学报,2004,20(2):239-248.
[10]曲晓明,侯增谦,黄卫.冈底斯斑岩铜矿(化)带:西藏的第二条玉龙铜矿带?[J].矿床地质,2001,20:355-366.
[11]Chung S L,Chu M F,Ji J Q,et al.The nature and timing of crustal thickening in Southern Tibet[J].Tectonophysics,2009,477:36-48.
[12]Dong G,Mo X,Zhao Z,et al.Geochronologic constraints on the magmatic underplating of the Gangdese Belt in the India-Eurasia collision:evidence of SHRIMPⅡzircon U-P bdating[J].Acta Geologica Sinica,2005,79:787-794.
[13]侯增谦,杨竹森,徐文艺,等.青藏高原碰撞造山带:Ⅰ.主碰撞造山成矿作用[J].矿床地质,2006,25:337-358.
[14]侯增谦,潘桂棠,王安建,等.青藏高原碰撞造山带:Ⅱ.晚碰撞转换成矿作用[J].矿床地质.2006,25(5):521-543.
[15]侯增谦,曲晓明,杨竹森,等.青藏高原碰撞造山带:Ⅲ.后碰撞伸展成矿作用[J].矿床地质,2006,25(6):629-651.
[16]杨志明,侯增谦,宋玉财,等.西藏驱龙超大型斑岩铜矿床:地质、蚀变与矿化[J].矿床地质,2008,27:279-318.
[17]孟祥金,侯增谦,高永丰,等.碰撞造山型斑岩铜矿蚀变分带模式--以西藏冈底斯斑岩铜矿带为例[J].地学前缘,2004,11(1):201-214.
[18]Camus F.The Andean porphyry systems[M].University of Tasmania,Centre for Ore Deposit Research Special Publication.2002,4:5-22.
[19]Deckart K,Silva W,Spr?hnle C,et al.Timing and duration of hydrothermal activity at the Los Bronces porphyry cluster:an update[J].Mineralium Deposita,2014,49(5):535-546.
[20]Schwartz M O.The porphyry copper deposit at La Granja,Peru[J].Economic Geology,1982,77:482-487.
[21]Camus F.The Andean porphyry systems[C]//Porter T M.Super porphyry copper and gold deposits:A global perspective.Linden Park,South Australia,Porter Geo Consultancy Publishing,2005:1-26.
[22]Barra F,Alcota H,Rivera S,et al.Timing and formation of porphyry Cu-Mo mineralization in the Chuquicamata district,northern Chile:new constraints from the Toki cluster[J].Mineralium Deposita,2013,48(5):629-651.
[23]郎兴海,唐菊兴,李志军,等.西藏冈底斯斑岩铜矿带雄村矿区侏罗纪成矿作用:来自锆石U-Pb和辉钼矿Re-Os年龄的证据[J].矿物学报,2013,S2:328.
[24]Hou Z Q,Gao Y F,Qu X M,et al.Origin of adakiticintrusives generated during mid-Miocene east-west extension in southern Tibet[J].Earth and Planetary Science Letters,2004,220:139-155.
[25]Yang Z M,Hou Z Q,White N C,et al.Geology of the post-collisional porphyry copper-molybdenum deposit at Qulong,Tibet[J].Ore Geology Review,2009,36:133-159.
[26]Chung S L,Liu D,Ji J,et al.Adakites from continental collision zones:melting of thickened lower crust beneath southern Tibet[J].Geology,2003,31:1021-1024.
[27]Xu W C,Zhang H F,Guo L,et al.Miocene high Sr/Y magmatism,south Tibet:Product of partial melting of subducted Indian continental crust and its tectonic implication[J].Lithos,2010,114:293-306.
[28]郑有业,高顺宝,程力军,等.西藏冲江大型斑岩铜(钼金)矿床的发现及意义[J].中国地质大学学报(地球科学版),2004,29(3):333-339.
[29]周维德,张正伟,袁盛朝,等.西藏尼木县白容斑岩型铜钼矿床特征及成矿期次[J].矿物岩石地球化学通报,2014,33(2):177-184.
[30]周玉,温春齐,周雄,等.西藏邦浦钼铜多金属矿床稀土元素特征[J].矿物学报,2009,增刊:363-364.
[31]周雄,温春齐,费光春,等.西藏邦铺斑岩型钼矿床二长花岗斑岩地球化学特征及构造意义[J].矿物岩石,2010,30(4):48-54.
[32]杨志明.西藏驱龙超大型斑岩铜矿床--岩浆作用及矿床成因[D].中国地质科学院博士学位论文,2008:1-145.
[33]Mo X X,Dong G C,Zhao Z D,et al.Timing of magma mixing in Gangdise magmatic belt during the India-Asia collision:zirconSHIRMP U-Pb dating[J].Acta Geologica Sinica,2005,79(1):66-76.
[34]赵志丹,莫宣学,Nomade S,等.青藏高原拉萨地块碰撞后超钾质岩石的时空分布及其意义[J].岩石学报,2006,22:787-794.
[35]Gao Y F,Hou Z Q,Wei R H.Post-collisional adakitic porphyries in Tibet:Geochemical and Sr-Nd-Pb isotopic constrains on partial melting of oceanic lithosphere and crust-mantle interaction[J].Acta Geologica Sinica,2003,77:123-135.
[36]Richards P J,Kerrich R.Adakite-like rocks:their diverse origins and questionable role in metallogenesis[J].Economic Geology,2007,102(4):537-576.
[37]Qu X M,Hou Z Q,Li Y G.Melt components derived from a subducted slab in late orogenic ore-bearing porphyries in the Gangdese copper belt,southern Tibetan plateau[J].Lithos,2004,74:131-148.
[38]Guo Z F,Wilson M,Liu J Q.Post-collisional adakites in south Tibet:Products of partial melting of subduction-modified lower crust[J].Lithos,2007,96:205-224.
[39]Gao Y F,Hou Z Q,Kamber B S,et al.Adakite-like porphyries from the southern Tibetan continental collision zones:evidence for slab meltmetasomatism[J].Contribution to Mineral Petrology,2007,153:105-120.
[40]Willett S D,Beaumont C.Subduction of Asian lithospheric mantle beneath Tibet inferred from models of continental collison[J].Nature,1994,369:642-645.
[41]Hou Z Q,Zhang H R,Pan X F,et al.Porphyry Cu(-Mo-Au)deposits related to melting of thickened mafic lower crust:Examples from the eastern Tethyanmetallogenic domain[J].Ore Geology Reviews,2011,39:21-45.