黔南乌龙沟铅锌矿床地质和S同位素地球化学
|
摘要
乌龙沟铅锌矿床位于三都—丹寨(三丹)多金属成矿带内,毗邻苗龙金锑矿床,是该成矿带内铅锌矿床的典型代表。但迄今为止,该矿床未见任何地质、地球化学等方面研究的报道,导致对其成因机制知之甚少。本文在系统的矿床地质研究基础上,对硫化物开展S同位素地球化学研究,以期揭示该矿床矿化剂元素的来源与演化,为理解其形成机制提供地球化学依据。乌龙沟铅锌矿床产于震旦系陡山沱组粉砂质白云岩中,明显受近NE、NW和SN向复合构造控制,矿体呈透镜状产出,具有块状、脉状和浸染状构造。矿石矿物主要有闪锌矿、方铅矿和黄铁矿,脉石矿物主要为白云石/方解石和石英,偶见重晶石。硫化物具有粒状、碎裂、交代等结构。矿床地质特征表明该矿床具有后成性。硫化物δ~(34)S值介于10.9‰～16.5‰,低于邻区赋存于早寒武碳酸盐中的三都牛场和都匀牛角塘铅锌矿床硫化物的δ~(34)S值(均大于20‰),也低于震旦-寒武纪海水硫酸盐的δ~(34)S值(20‰～35‰)。可见,乌龙沟铅锌矿床还原S很可能是海相硫酸盐热化学(TSR)的产物,而TSR的温度或其它S源的加入可能是导致其具有低于邻区矿床δ~(34)S值的主要原因。综上,本文认为乌龙沟铅锌矿床属于受构造和岩性控制的后生热液矿床,其S源主要为海相硫酸盐。由于缺乏其它地球化学和年代学的约束,其是否为MVT矿床,尚需进一步的深入研究。
The Wulonggou Pb-Zn deposit is a typical representative of Pb-Zn deposits in the Sandu-Danzhai(Sandan) polymetallic metallogenic belt and is adjacent to the Miaolong Au-Sb deposit. So far, no report on its geology and geochemistry has been presented, thus little is known about its genetic mechanism. Based on the systematic geological study, the S isotopic geochemistry of sulfide minerals has been carried out in this paper in order to reveal the source and evolution of the mineralizer elements of the Wulonggou deposit, and to provide a geochemical basis for understanding its formation mechanism. Orebodies of the Wulonggou Pb-Zn deposit occurred in silty dolostone of the Sinian Doushantuo Formation and are obviously controlled by the NE-, NW-and SN-trending composite structures. The ore bodies are lenticular, with massive, veining, and dissemination structures for its ores. The sulfide minerals are mainly sphalerite, galena and pyrite, and the gangue minerals are mainly dolomite/calcite and quartz with occasional barite. Sulfide minerals have granular, cataclastic, and metasomatic textures. The geological characteristics of this deposit indicate that it has post-ore properties. The δ~(34)S values of sulfides, varying from 10.9‰ to 16.5‰, are lower than those of sulfides in the Sandu Niuchang and Duyun Niujiaotang Pb-Zn deposits that are hosted in early Cambrian carbonate rocks in the adjacent area(all>20‰), and lower than those of the Sinian-Cambrian seawater sulfate(20‰-35‰). It can be seen that reduced S of the Wulonggou deposit could be produced by the marine sulfate thermochemical reduction(TSR). The temperature of TSR or the input of other S sources could be the main reason resulting in its lower δ~(34)S values than those of the adjacent deposits. In summary, it is believed that the Wulonggou deposit belongs to an epigenetic hydrothermal deposit that is controlled by structure and lithology, and its S was mainly sourced from the marine sulfate. Due to the lack of other geochemical and chronological constraints, to confirm whether it is an MVT deposit or not requires further research.
The Wulonggou Pb-Zn deposit is a typical representative of Pb-Zn deposits in the Sandu-Danzhai(Sandan) polymetallic metallogenic belt and is adjacent to the Miaolong Au-Sb deposit. So far, no report on its geology and geochemistry has been presented, thus little is known about its genetic mechanism. Based on the systematic geological study, the S isotopic geochemistry of sulfide minerals has been carried out in this paper in order to reveal the source and evolution of the mineralizer elements of the Wulonggou deposit, and to provide a geochemical basis for understanding its formation mechanism. Orebodies of the Wulonggou Pb-Zn deposit occurred in silty dolostone of the Sinian Doushantuo Formation and are obviously controlled by the NE-, NW-and SN-trending composite structures. The ore bodies are lenticular, with massive, veining, and dissemination structures for its ores. The sulfide minerals are mainly sphalerite, galena and pyrite, and the gangue minerals are mainly dolomite/calcite and quartz with occasional barite. Sulfide minerals have granular, cataclastic, and metasomatic textures. The geological characteristics of this deposit indicate that it has post-ore properties. The δ~(34)S values of sulfides, varying from 10.9‰ to 16.5‰, are lower than those of sulfides in the Sandu Niuchang and Duyun Niujiaotang Pb-Zn deposits that are hosted in early Cambrian carbonate rocks in the adjacent area(all>20‰), and lower than those of the Sinian-Cambrian seawater sulfate(20‰-35‰). It can be seen that reduced S of the Wulonggou deposit could be produced by the marine sulfate thermochemical reduction(TSR). The temperature of TSR or the input of other S sources could be the main reason resulting in its lower δ~(34)S values than those of the adjacent deposits. In summary, it is believed that the Wulonggou deposit belongs to an epigenetic hydrothermal deposit that is controlled by structure and lithology, and its S was mainly sourced from the marine sulfate. Due to the lack of other geochemical and chronological constraints, to confirm whether it is an MVT deposit or not requires further research.
引文
[1]彭扬奇.贵州三都-丹寨成矿带金矿地质特征、成矿规律及找矿远景[J].西南矿产地质,1997,11(3):1-15.
[2]谢卓君,夏勇,闫宝文,等.贵州省三都-丹寨成矿带中卡林型金矿地球化学特征及成矿物质来源初探[J].矿物岩石地球化学通报,2014,33(3):326-333.
[3]陈恨水,赵生龙,熊伟.贵州省三都-丹寨地区金矿成矿规律及潜力预测[J].矿物学报,2014,34(4):521-527.
[4]张燕,陈翠华,顾雪祥,等.贵州三都苗龙金-锑矿床金赋存状态初步探讨[J].中国地质,2014,41(5):1620-1635.
[5]孙国涛,沈能平,苏文超,等.贵州苗龙金锑矿床方解石微量元素、Sr-Nd同位素地球化学特征及其意义[J].矿物学报,2016,36(3):404-412.
[6]张信伦.贵州省丹寨县排庭金矿成矿条件分析[J].矿产与地质,2017,31(3):539-542+550.
[7]范二川.贵州丹寨排庭金矿床控矿因素及找矿方向[J].矿产与地质,2010,24(4):322-327.
[8]王华云,施继锡.贵州丹寨、三都、都匀地区低温成矿系列的成矿物质来源和分异条件[J].矿物学报,1997,17(4):491-500.
[9]李堃,吴昌雄,汤朝阳,等.湘西黔东地区铅锌矿床C、O同位素地球化学特征及其对成矿过程的指示[J].中国地质,2014,41(5):1608-1619.
[10]蔡应雄,杨红梅,段瑞春,等.湘西-黔东下寒武统铅锌矿床流体包裹体和硫、铅、碳同位素地球化学特征[J].现代地质,2014,28(1):29-41.
[11]段其发,曹亮,曾健康,等.湘西花垣矿集区狮子山铅锌矿床闪锌矿Rb-Sr定年及地质意义[J].地球科学(中国地质大学学报),2014,39(8):977-986+999.
[12]Ye L,Cook NJ,Liu T,et al.The Niujiaotang Cd-rich zinc deposit,Duyun,Guizhou province,southwest China:ore genesis and mechanisms of cadmium concentration[J].Mineralium Deposita,2012,47(6):683-700.
[13]陈国勇,安琦,范玉梅.黔东地区铅锌矿地质特征及成矿作用分析[J].贵州地质,2005,22(4):252-259.
[14]Zhou JX,Xiang ZZ,Zhou MF,et al.The giant Upper Yangtze Pb-Zn province in SW China:Reviews,new advances and a new genetic model[J].Journal of Asian Earth Sciences,2018,154:280-315.
[15]Zhou JX,Wang XC,Wilde SA,et al.New insights into the metallogeny of MVT Zn-Pb deposits:A case study from the Nayongzhi in South China,using field data,fluid compositions,and in situ S-Pb isotopes[J].American Mineralogist,2018,103(1):91-108.
[16]金中国,周家喜,黄智龙,等.贵州普定纳雍枝铅锌矿矿床成因:S和原位Pb同位素证据[J].岩石学报,2016,32(11):3441-3455.
[17]周家喜,黄智龙,周国富,等.黔西北赫章天桥铅锌矿床成矿物质来源:S、Pb同位素和REE制约[J].地质论评,2010,56(4):513-524
[18]Zhou J,Huang Z,Zhou M,et al.Constraints of C-O-S-Pb isotope compositions and Rb-Sr isotopic age on the origin of the Tianqiao carbonate-hosted Pb-Zn deposit,SW China[J].Ore Geology Reviews,2013,53:77-92.
[19]周家喜,黄智龙,周国富,等.黔西北天桥铅锌矿床热液方解石C、O同位素和REE地球化学[J].大地构造与成矿学,2012,36(1):93-101.
[20]贵州省地质调查院,编著.中国区域地质志-贵州志[M].北京:地质出版社,2017,1-200.
[21]王亮.贵州东南部深部构造与区域矿产的关系[J].贵州地质,2003,20(2):75-79.
[22]卢焕章,王中刚,吴学益,等.贵州东南部的地质构造与金矿床的关系[J].地质学报,2005,79(1):99-105+150.
[23]杨坤光,李学刚,戴传固,等.黔东南隔槽式褶皱成因分析[J].地学前缘,2012,19(5):53-60.
[24]陈翠华,张燕,顾雪祥,等.贵州苗龙金矿床毒砂中金的赋存状态研究[J].矿床地质,2013,32(5):932-940.
[25]叶霖,潘自平,李朝阳,等.贵州都匀牛角塘富镉锌矿同位素地球化学研究[J].矿物岩石,2005,25(2):70-74.
[26]郑永飞,陈江峰.稳定同位素地球化学[M].北京:地质出版社,2000.
[27]Chaussidon M,Albarède F,Sheppard SMF.Sulphur isotope variations in the mantle from ion microprobe analyses of micro-sulphide inclusions[J].Earth Planet Sci Lett.,1989,92:144-156
[28]Zhou J,Huang Z,Bao G,et al.Sources and thermo-chemical sulfate reduction for reduced sulfur in the hydrothermal fluids,southeastern SYG Pb-Zn metallogenic province,SW China[J].Journal of Earth Science,2013,24(5):759-771.
[29]Ohmoto H.Systematics of sulfur and carbon isotopes in hydrothermal ore deposits[J].Economic Geology,1972,67:551-579.
[30]Basuki NI,Taylor BE,Spooner ETC.Sulfur isotope evidence for thermo-chemical reduction of dissolved sulfate in Mississippi valley type zinc-lead mineralization,Bongara area,northern Peru[J].Economic Geology,2008,103:183-799.
[31]Seal IR.Sulfur isotope geochemistry of sulfide minerals[J].Review of Mineralogy and Geochemistry,2006,61:633-677.
[32]J?rgenson B B,Isaksen M F,Jannasch HW.Bacterial sulfate reduction above 100°C in deep sea hydrothermal vent sediments[J].Science,1992,258:1756-1757.
[33]Kajiwara Y,Krouse H R.Sulfur isotope partitioning in metallic sulfide systems[J].Canadian Journal of Earth Sciences,1971,8(11):1397-1408.
[34]周家喜,黄智龙,周国富,等.贵州天桥铅锌矿床分散元素赋存状态及规律[J].矿物学报,2009,29(4):471-480.
[35]周家喜,黄智龙,高建国,等.滇东北茂租大型铅锌矿床成矿物质来源及成矿机制[J].矿物岩石,2012,32(3):62-69.
[2]谢卓君,夏勇,闫宝文,等.贵州省三都-丹寨成矿带中卡林型金矿地球化学特征及成矿物质来源初探[J].矿物岩石地球化学通报,2014,33(3):326-333.
[3]陈恨水,赵生龙,熊伟.贵州省三都-丹寨地区金矿成矿规律及潜力预测[J].矿物学报,2014,34(4):521-527.
[4]张燕,陈翠华,顾雪祥,等.贵州三都苗龙金-锑矿床金赋存状态初步探讨[J].中国地质,2014,41(5):1620-1635.
[5]孙国涛,沈能平,苏文超,等.贵州苗龙金锑矿床方解石微量元素、Sr-Nd同位素地球化学特征及其意义[J].矿物学报,2016,36(3):404-412.
[6]张信伦.贵州省丹寨县排庭金矿成矿条件分析[J].矿产与地质,2017,31(3):539-542+550.
[7]范二川.贵州丹寨排庭金矿床控矿因素及找矿方向[J].矿产与地质,2010,24(4):322-327.
[8]王华云,施继锡.贵州丹寨、三都、都匀地区低温成矿系列的成矿物质来源和分异条件[J].矿物学报,1997,17(4):491-500.
[9]李堃,吴昌雄,汤朝阳,等.湘西黔东地区铅锌矿床C、O同位素地球化学特征及其对成矿过程的指示[J].中国地质,2014,41(5):1608-1619.
[10]蔡应雄,杨红梅,段瑞春,等.湘西-黔东下寒武统铅锌矿床流体包裹体和硫、铅、碳同位素地球化学特征[J].现代地质,2014,28(1):29-41.
[11]段其发,曹亮,曾健康,等.湘西花垣矿集区狮子山铅锌矿床闪锌矿Rb-Sr定年及地质意义[J].地球科学(中国地质大学学报),2014,39(8):977-986+999.
[12]Ye L,Cook NJ,Liu T,et al.The Niujiaotang Cd-rich zinc deposit,Duyun,Guizhou province,southwest China:ore genesis and mechanisms of cadmium concentration[J].Mineralium Deposita,2012,47(6):683-700.
[13]陈国勇,安琦,范玉梅.黔东地区铅锌矿地质特征及成矿作用分析[J].贵州地质,2005,22(4):252-259.
[14]Zhou JX,Xiang ZZ,Zhou MF,et al.The giant Upper Yangtze Pb-Zn province in SW China:Reviews,new advances and a new genetic model[J].Journal of Asian Earth Sciences,2018,154:280-315.
[15]Zhou JX,Wang XC,Wilde SA,et al.New insights into the metallogeny of MVT Zn-Pb deposits:A case study from the Nayongzhi in South China,using field data,fluid compositions,and in situ S-Pb isotopes[J].American Mineralogist,2018,103(1):91-108.
[16]金中国,周家喜,黄智龙,等.贵州普定纳雍枝铅锌矿矿床成因:S和原位Pb同位素证据[J].岩石学报,2016,32(11):3441-3455.
[17]周家喜,黄智龙,周国富,等.黔西北赫章天桥铅锌矿床成矿物质来源:S、Pb同位素和REE制约[J].地质论评,2010,56(4):513-524
[18]Zhou J,Huang Z,Zhou M,et al.Constraints of C-O-S-Pb isotope compositions and Rb-Sr isotopic age on the origin of the Tianqiao carbonate-hosted Pb-Zn deposit,SW China[J].Ore Geology Reviews,2013,53:77-92.
[19]周家喜,黄智龙,周国富,等.黔西北天桥铅锌矿床热液方解石C、O同位素和REE地球化学[J].大地构造与成矿学,2012,36(1):93-101.
[20]贵州省地质调查院,编著.中国区域地质志-贵州志[M].北京:地质出版社,2017,1-200.
[21]王亮.贵州东南部深部构造与区域矿产的关系[J].贵州地质,2003,20(2):75-79.
[22]卢焕章,王中刚,吴学益,等.贵州东南部的地质构造与金矿床的关系[J].地质学报,2005,79(1):99-105+150.
[23]杨坤光,李学刚,戴传固,等.黔东南隔槽式褶皱成因分析[J].地学前缘,2012,19(5):53-60.
[24]陈翠华,张燕,顾雪祥,等.贵州苗龙金矿床毒砂中金的赋存状态研究[J].矿床地质,2013,32(5):932-940.
[25]叶霖,潘自平,李朝阳,等.贵州都匀牛角塘富镉锌矿同位素地球化学研究[J].矿物岩石,2005,25(2):70-74.
[26]郑永飞,陈江峰.稳定同位素地球化学[M].北京:地质出版社,2000.
[27]Chaussidon M,Albarède F,Sheppard SMF.Sulphur isotope variations in the mantle from ion microprobe analyses of micro-sulphide inclusions[J].Earth Planet Sci Lett.,1989,92:144-156
[28]Zhou J,Huang Z,Bao G,et al.Sources and thermo-chemical sulfate reduction for reduced sulfur in the hydrothermal fluids,southeastern SYG Pb-Zn metallogenic province,SW China[J].Journal of Earth Science,2013,24(5):759-771.
[29]Ohmoto H.Systematics of sulfur and carbon isotopes in hydrothermal ore deposits[J].Economic Geology,1972,67:551-579.
[30]Basuki NI,Taylor BE,Spooner ETC.Sulfur isotope evidence for thermo-chemical reduction of dissolved sulfate in Mississippi valley type zinc-lead mineralization,Bongara area,northern Peru[J].Economic Geology,2008,103:183-799.
[31]Seal IR.Sulfur isotope geochemistry of sulfide minerals[J].Review of Mineralogy and Geochemistry,2006,61:633-677.
[32]J?rgenson B B,Isaksen M F,Jannasch HW.Bacterial sulfate reduction above 100°C in deep sea hydrothermal vent sediments[J].Science,1992,258:1756-1757.
[33]Kajiwara Y,Krouse H R.Sulfur isotope partitioning in metallic sulfide systems[J].Canadian Journal of Earth Sciences,1971,8(11):1397-1408.
[34]周家喜,黄智龙,周国富,等.贵州天桥铅锌矿床分散元素赋存状态及规律[J].矿物学报,2009,29(4):471-480.
[35]周家喜,黄智龙,高建国,等.滇东北茂租大型铅锌矿床成矿物质来源及成矿机制[J].矿物岩石,2012,32(3):62-69.