四川石棉碲矿床元素地球化学研究
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摘要
四川石棉碲矿床是世界首例以分散元素Te为主的独立碲矿床。该矿床位于扬子地块与地槽的拼接部位,与泸定-冕宁区域韧性剪切带密切相关,受控于韧性-脆性剪切构造岩片和隐伏花岗岩底辟热穹隆构造。矿床产于西油房和子耳山围限的豆荚状构造片岩之中。围岩为三叠纪变基性火山岩及大理岩,绿片岩和千枚岩。热液蚀变主要为碳酸岩化和硅化等。矿体呈脉状产出。主要矿石矿物为楚碲铋矿,其是辉碲铋矿、硫碲铋矿、碲金矿、六方碲银矿等。
本文以野外地质研究及室内测试数据为依据,采用大地构造学及构造地球化学的理论和研究方法,研究了碲矿床形成的区域地质构造背景。采用矿床学、矿床地球化学、成因矿物学的理论和研究方法,研究了碲矿化特征、矿体特征、热液蚀变类型及其空间分布、矿石类型及其特征、矿石结构构造、矿物共生组合特点。并利用现代先进的ICP-MS仪器分析测试岩石、矿石样品的微量元素组成分,采用电子探针分析测定矿石碲矿物的组成。利用多元统计学方法对岩矿样品的分析测试结果进行了数据处理。利用微量元素、稀土元素的研究方法进行了元素对比值及元素分布型式研究。研究结果表明:
1.碲矿床发育在深大断裂构造及构造-岩浆强烈活动地带。这种地带不仅为碲矿床的形成体供了良好的赋矿空间及成矿流体活动场所,更重要的是为分散元素Te源源不断地聚集成矿提供了丰富的物质来源。
2.分散元素Te之所以能在该区富集并形成矿床,与成矿热流体中Te的来源有关。Te来自深部,可能与燕山期中酸性岩浆活动有关。
3.碲矿物组成的电子探针分析测定表明,在矿石矿物楚碲铋矿中,Te的最低含量为40.08%,最高为41.52%,平均为40.70%。Bi的最低含量为59.00%,最高为59.92%,平均为59.30%。Te/Bi值为0.68。这表明碲矿物中,导致Te高度富集的原因还可能与成矿热流体中Bi、S、Fe、Ca、Mg的高含量有关。
The tellurium deposit, Shimian county, Sichuan, is as the first and the only example of tellurium-dominated ore deposit in the world at present. It is located in the connecting part between the geosycline and the Yangtze platform, and it is enclosed by the Luding-Mianning regional ductile shear zone. The host rocks for the mineralization are of Triassic metamafic rock and dynamothermal metamorphic marble, greenschist and phyllite. The deposit is controlled by a ductile-britttle shear zone and by ahidden granite diaper-thermal dome. The ore bodies are as veins in the deposit. Wall-rock alterations are extensively developed there, such as muscovitization, ankeritation, silication, sericitization, tourmalinization, chloritization and so on. But the alterations is both of carbonatization and silicification.
Based on large geological investigations in the flied and a lot of analytical data gained in the laboratory, this author is studying on the element geochemical characteristics of the deposit. This study covers regional geology, ore deposit geology and element geochemistry. The regional geologic settings is studied by applying the modern thoughts and basic methods of architectonices and tectonic-geochemistry. The ore deposit, Te-mineralization, ore bodies, hydrothermal alteration, mineral paragenesis and so on are researched by applying the modern thoughts and basic methods of metallogeny, geochemistry, mineral geology. Trace element contents of the rocks and the ore are separately analyzed by ICP-MS and EMP. The main results are as follow:
①Te deposit are closely related with deep faults and tectonic-magmatic belt, which its not only to reserve space for Te element to take enriching and depositing, but also to provide continuously Te-resource for Te-mineralization .
②Te-source is provided by the blind Te-rich granites, rather than stratigraphic rocks. Genetic mineralogy and geochemistry indicate that the Te-mineralization in the deposit is possibly related to the buried Te-rich granites.
③EMP data suggest that content of Te changes from 40.08% to 41.52% averaged 40.70%, while Bi is from 59.00% to 59.92% averaged 59.30%. Ration of Te/Bi is 0.68. The high content of Te may have a relationship of enrichment of Bi、S、Fe、Ca、Mg in mineralizing fluid.
本文以野外地质研究及室内测试数据为依据,采用大地构造学及构造地球化学的理论和研究方法,研究了碲矿床形成的区域地质构造背景。采用矿床学、矿床地球化学、成因矿物学的理论和研究方法,研究了碲矿化特征、矿体特征、热液蚀变类型及其空间分布、矿石类型及其特征、矿石结构构造、矿物共生组合特点。并利用现代先进的ICP-MS仪器分析测试岩石、矿石样品的微量元素组成分,采用电子探针分析测定矿石碲矿物的组成。利用多元统计学方法对岩矿样品的分析测试结果进行了数据处理。利用微量元素、稀土元素的研究方法进行了元素对比值及元素分布型式研究。研究结果表明:
1.碲矿床发育在深大断裂构造及构造-岩浆强烈活动地带。这种地带不仅为碲矿床的形成体供了良好的赋矿空间及成矿流体活动场所,更重要的是为分散元素Te源源不断地聚集成矿提供了丰富的物质来源。
2.分散元素Te之所以能在该区富集并形成矿床,与成矿热流体中Te的来源有关。Te来自深部,可能与燕山期中酸性岩浆活动有关。
3.碲矿物组成的电子探针分析测定表明,在矿石矿物楚碲铋矿中,Te的最低含量为40.08%,最高为41.52%,平均为40.70%。Bi的最低含量为59.00%,最高为59.92%,平均为59.30%。Te/Bi值为0.68。这表明碲矿物中,导致Te高度富集的原因还可能与成矿热流体中Bi、S、Fe、Ca、Mg的高含量有关。
The tellurium deposit, Shimian county, Sichuan, is as the first and the only example of tellurium-dominated ore deposit in the world at present. It is located in the connecting part between the geosycline and the Yangtze platform, and it is enclosed by the Luding-Mianning regional ductile shear zone. The host rocks for the mineralization are of Triassic metamafic rock and dynamothermal metamorphic marble, greenschist and phyllite. The deposit is controlled by a ductile-britttle shear zone and by ahidden granite diaper-thermal dome. The ore bodies are as veins in the deposit. Wall-rock alterations are extensively developed there, such as muscovitization, ankeritation, silication, sericitization, tourmalinization, chloritization and so on. But the alterations is both of carbonatization and silicification.
Based on large geological investigations in the flied and a lot of analytical data gained in the laboratory, this author is studying on the element geochemical characteristics of the deposit. This study covers regional geology, ore deposit geology and element geochemistry. The regional geologic settings is studied by applying the modern thoughts and basic methods of architectonices and tectonic-geochemistry. The ore deposit, Te-mineralization, ore bodies, hydrothermal alteration, mineral paragenesis and so on are researched by applying the modern thoughts and basic methods of metallogeny, geochemistry, mineral geology. Trace element contents of the rocks and the ore are separately analyzed by ICP-MS and EMP. The main results are as follow:
①Te deposit are closely related with deep faults and tectonic-magmatic belt, which its not only to reserve space for Te element to take enriching and depositing, but also to provide continuously Te-resource for Te-mineralization .
②Te-source is provided by the blind Te-rich granites, rather than stratigraphic rocks. Genetic mineralogy and geochemistry indicate that the Te-mineralization in the deposit is possibly related to the buried Te-rich granites.
③EMP data suggest that content of Te changes from 40.08% to 41.52% averaged 40.70%, while Bi is from 59.00% to 59.92% averaged 59.30%. Ration of Te/Bi is 0.68. The high content of Te may have a relationship of enrichment of Bi、S、Fe、Ca、Mg in mineralizing fluid.
引文
[1]四川省地质矿产局.四川省区域地质志[M].北京:地质出版社,1991,220-221.
[2]骆耀南等,四川发现世界首例独立碲矿床。中国地质,1994(4):27-29;
[3]骆耀南,傅德明,周绍东.四川石棉大水沟碲矿床地质与成因[J].四川地质学报,1994,14(2):100-110.
[4]郭建强,游再平,王大可.松潘—甘孜造山带东缘大水沟地区变质变形作用[J].中国区域地质,1999: 312-319
[5]李保华,曹志敏,温春齐.大水沟碲矿床矿脉特征及包裹体类型[J].矿物岩石地球化学通报, 2000, 19(4):346-347
[6]郑大中,郑若锋.大水沟独立碲矿床形成机理研究.地质找矿论丛.2000,15(3)230-237;
[7]曹志敏.大水沟碲矿床成矿条件与碲的矿机理研究[D].成都理工大学博士论文,1995.
[8]温春齐.四川大水沟碲矿床成矿物质来源研究[J].成都理工学院学报.2002.10(5):526-532
[9]毛景文,魏家秀.大水沟碲矿床流体包裹体的He、Ar同位素组成及其示踪成矿流体的来源[J].地球学报. 2002.2(1):58-61
[10]西油房幅.区域调查报告.四川省地质矿产局区域地质调查队. 1996.5
[11]何明友.论云南老王寨金矿田形成的地球化学机理[D].博士后科学研究论文.1996
[12]刘英俊,曹励明.元素地球化学[M].科学出版社.1984
[13]涂光炽等.分散元素地球化学及成矿机制[M].地质出版社.2004.2
[14]毛景文,陈毓川等.四川石棉县大水沟碲多金属矿床辉碲铋矿研究[J].地质科学.1995.30(1):47-52
[15]石棉幅.区域调查报告.四川省地质矿产局区域地质调查队.1974.1
[2]骆耀南等,四川发现世界首例独立碲矿床。中国地质,1994(4):27-29;
[3]骆耀南,傅德明,周绍东.四川石棉大水沟碲矿床地质与成因[J].四川地质学报,1994,14(2):100-110.
[4]郭建强,游再平,王大可.松潘—甘孜造山带东缘大水沟地区变质变形作用[J].中国区域地质,1999: 312-319
[5]李保华,曹志敏,温春齐.大水沟碲矿床矿脉特征及包裹体类型[J].矿物岩石地球化学通报, 2000, 19(4):346-347
[6]郑大中,郑若锋.大水沟独立碲矿床形成机理研究.地质找矿论丛.2000,15(3)230-237;
[7]曹志敏.大水沟碲矿床成矿条件与碲的矿机理研究[D].成都理工大学博士论文,1995.
[8]温春齐.四川大水沟碲矿床成矿物质来源研究[J].成都理工学院学报.2002.10(5):526-532
[9]毛景文,魏家秀.大水沟碲矿床流体包裹体的He、Ar同位素组成及其示踪成矿流体的来源[J].地球学报. 2002.2(1):58-61
[10]西油房幅.区域调查报告.四川省地质矿产局区域地质调查队. 1996.5
[11]何明友.论云南老王寨金矿田形成的地球化学机理[D].博士后科学研究论文.1996
[12]刘英俊,曹励明.元素地球化学[M].科学出版社.1984
[13]涂光炽等.分散元素地球化学及成矿机制[M].地质出版社.2004.2
[14]毛景文,陈毓川等.四川石棉县大水沟碲多金属矿床辉碲铋矿研究[J].地质科学.1995.30(1):47-52
[15]石棉幅.区域调查报告.四川省地质矿产局区域地质调查队.1974.1