攀枝花大田地区辉绿岩脉/花岗质岩脉年代学特征及其地质意义
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摘要
以分布于攀枝花大田地区侵入于混合岩中的辉绿岩脉和花岗质岩脉为研究对象,采集不同方向的辉绿岩脉和花岗质岩脉进行LA-ICP-MS锆石U-Pb定年,探讨它们形成地质背景、时代及其意义。研究结果表明:(1)不同方向辉绿岩脉的年龄集中在770～780 Ma之间,花岗质岩脉的年龄集中在760～770 Ma之间;(2)在时空上,辉绿岩脉和花岗岩脉具有双峰式岩浆活动的特点,应是Rodinia大陆裂解过程中岩浆上侵的产物;(3)岩脉的形成时代限制了研究区混合岩的形成下限,即大田地区的混合岩的形成时代早于780 Ma;(4)大田地区辉绿岩脉/花岗质岩脉与构造蚀变带中的花岗质及长英质脉体的形成时代一致,结合大田地区505铀矿的形成时代和产出的空间位置,认为攀枝花大田地区铀矿的形成与导致辉绿岩脉和花岗质岩脉形成的岩浆活动有着密切的关系,提供了热源和流体来源。研究成果为该区铀矿成矿规律的探究及找矿具有重要的意义。
Samples of diabase and granitic dikes in different directions which intruded into migmatite in Datian area, Panzhihua were collected for LA-ICP-MS zircon U-Pb dating so as to discussed their geological background, formation age and significance. The results shewed that:(1) the ages of diabase dikes in different directions are between 770 Ma and 780 Ma, and granitic dikes are between 760 Ma and770 Ma;(2) diabase dikes and granite dikes have the characteristics of bimodal magmatic activity in time and space, which should be the product of magma invasion during the cracking process of Rodinia continent;( 3) the formation age of dikes constricted the formation time of migmatization in the study area, the migmatite was formed before 780 Ma;(4) The age of diabase dikes/granite dikes is consistent with that of granite and felsic dikes in the structural alteration zone. Based on the above feature and the formation time and spatial location of 505 uranium deposit in Datian area, it is believed that the formation of uranium deposits was closely related to the magmatic activity resulted from diabase and granitic dike in Panzhihua Datian, which may provide heat and fluid sources to the uranium mineralization.
Samples of diabase and granitic dikes in different directions which intruded into migmatite in Datian area, Panzhihua were collected for LA-ICP-MS zircon U-Pb dating so as to discussed their geological background, formation age and significance. The results shewed that:(1) the ages of diabase dikes in different directions are between 770 Ma and 780 Ma, and granitic dikes are between 760 Ma and770 Ma;(2) diabase dikes and granite dikes have the characteristics of bimodal magmatic activity in time and space, which should be the product of magma invasion during the cracking process of Rodinia continent;( 3) the formation age of dikes constricted the formation time of migmatization in the study area, the migmatite was formed before 780 Ma;(4) The age of diabase dikes/granite dikes is consistent with that of granite and felsic dikes in the structural alteration zone. Based on the above feature and the formation time and spatial location of 505 uranium deposit in Datian area, it is believed that the formation of uranium deposits was closely related to the magmatic activity resulted from diabase and granitic dike in Panzhihua Datian, which may provide heat and fluid sources to the uranium mineralization.
引文
[1]姚建,李巨初,周君,等.四川攀枝花大田地区混合岩LA-ICP-MS锆石U-Pb测年及其地质意义[J].地质通报, 2017, 36(2-3):381-391.
[2]胥德恩.康滇地轴地壳演化与铀成矿作用探讨[J].铀矿地质, 1992, 8(6):348-354.
[3]李复汉,覃嘉铭,申玉连,等.康滇地区的前震旦系[M].重庆:重庆出版社, 1988:20-22, 94-100.
[4]张成江,陈友良,李巨初,等.康滇地轴巨粒晶质铀矿的发现及其地质意义[J].地质通报,2015, 34(12):2219-2226.
[5]徐争启,张成江,欧阳鑫东,等.攀枝花大田铀矿床年代学特征及其意义[J].铀矿地质, 2017, 33(5):280-287.
[6]袁海华,张树发,张平.渡口市同德混合片麻岩初获太古宙年龄信息[J].成都理工大学学报(自然科学版), 1985, 8(3):79-84.
[7]袁海华,张树发,张平.康滇地轴结晶基底的时代归属[J].成都理工大学学报(自然科学版),1986, 13(4):64-70.
[8]丛柏林.攀西古裂谷的形成与演化[M].北京:科学出版社, 1988:1-96.
[9]李复汉,覃嘉敏,申玉连,等.康滇地区的前震旦系[M].重庆:重庆出版社, 1988:109-149.
[10]胥德恩,陈友良,张应全,等.康定杂岩的时代及成因探讨[J].地质论评, 1995, 41(2):101-111.
[11]陈岳龙,罗照华,赵俊香,等.从锆石SHRIMP年龄及岩石地球化学特征论四川冕宁康定杂岩的成因[J].中国科学(D辑), 2004, 34(8):687-697.
[12]杜利林,耿元生,杨崇辉,等.扬子地台西缘康定群的再认识:来自地球化学和年代学证据[J].地质学报, 2007, 81(11):1562-1577.
[13]耿元生,杨崇辉,王新社,等.扬子地台西缘结晶基底时代[J].高校地质学报, 2007, 13(3):429-441.
[14]范晨子,胡明月,赵令浩,等.锆石铀-铅定年激光剥蚀-电感耦合等离子体质谱原位微区分析进展[J].岩矿测试, 2012, 31(1):29-46.
[15]李怀坤,耿建珍,郝爽,等.用激光烧蚀多接收器等离子体质谱仪(LA-MC-ICPMS)测定锆石UPb同位素年龄的研究[J].矿物学报, 2009,(增刊):600-601.
[16]Ludwig K R. A Geochronological Toolkit for Microsoft Excel[M]. Berkeley:Berkeley Geochronology Center Special Publication,2003, 49(2):1-56.
[17]刘建辉,刘敦一,张玉海,等.使用SHRIMP测定锆石铀-铅年龄的选点技巧[J].岩矿测试,2011, 30(3):265-268.
[18]姚建.攀枝花市大田地区混合岩成因研究[D].成都:成都理工大学, 2014.
[19]李莎莎.四川攀枝花(505)地区混合岩地球化学特征及其与铀成矿关系[D].成都:成都理工大学,2011.
[20]LI Z X, LI X H, KINNY P D, etal. The breakup of Rodinia:Did it start with a mantle plume beneath South China?[J]. EarthPlanet Sci Lett,1999, 173:171-181.
[21]LI Z X, LI X H, KINNY P D, etal. Doesit take a superplume to breakup a supercontinent?—a case for Rodinia[J]. GeolSocAust Abst, 2001, 65:74-77.
[22]LI Z X, LI X H, KINNY P D, etal.Geochronology of Neoproterozoic syn-rift magmatism in the Yangtze Craton, South China and correlations with other continents:evidence for amantle superplume that broke up Rodinia[J].Precambrian Research, 2003, 10(122):85-109.
[23]Li Xianhua, Zhu Weiguang, Zhong Hong, et al.The Tongde picrite dikes in the Western Yangtze Block:Evidence for ca.800 Ma mantle plume magmatism in South China during the breakup of Rodinia[J]. The Journal of Geology, 2010, 118(5):509-522.
[24]Lin Guangchun, Li Xianhua, Li Wuxian. SHRIMP U-Pb zircon age, geochemistry and Nd-Hf isotope of Neoproterozoic mafic dyke swarm in Western Sichuan:Petrogenesis and tectonic significance[J]:Science in China(Series D), 2007, 50(1):1-16.
[25]Zhu Weiguang, Zhong Hong, Deng Hailin, et al.SHRIMP zircon U-Pb geochronology, elemental and Nd isotopic geochemistry of the Neoproterozoic mafic dykes in the Yanbian area. SW China[J].Precambrian Research, 2008, 164(1/2):66-85.
[26]徐争启,欧阳鑫东,张成江,等.电子探针化学测年在攀枝花大田晶质铀矿中的应用及其意义[J].岩矿测试, 2017, 36(6):641-648.
[27]王红军,李巨初,薛钧月.康滇地轴元古代成矿作用对Rodinia事件的响应[J].地质学报,2009, 29(1):11-15.
[2]胥德恩.康滇地轴地壳演化与铀成矿作用探讨[J].铀矿地质, 1992, 8(6):348-354.
[3]李复汉,覃嘉铭,申玉连,等.康滇地区的前震旦系[M].重庆:重庆出版社, 1988:20-22, 94-100.
[4]张成江,陈友良,李巨初,等.康滇地轴巨粒晶质铀矿的发现及其地质意义[J].地质通报,2015, 34(12):2219-2226.
[5]徐争启,张成江,欧阳鑫东,等.攀枝花大田铀矿床年代学特征及其意义[J].铀矿地质, 2017, 33(5):280-287.
[6]袁海华,张树发,张平.渡口市同德混合片麻岩初获太古宙年龄信息[J].成都理工大学学报(自然科学版), 1985, 8(3):79-84.
[7]袁海华,张树发,张平.康滇地轴结晶基底的时代归属[J].成都理工大学学报(自然科学版),1986, 13(4):64-70.
[8]丛柏林.攀西古裂谷的形成与演化[M].北京:科学出版社, 1988:1-96.
[9]李复汉,覃嘉敏,申玉连,等.康滇地区的前震旦系[M].重庆:重庆出版社, 1988:109-149.
[10]胥德恩,陈友良,张应全,等.康定杂岩的时代及成因探讨[J].地质论评, 1995, 41(2):101-111.
[11]陈岳龙,罗照华,赵俊香,等.从锆石SHRIMP年龄及岩石地球化学特征论四川冕宁康定杂岩的成因[J].中国科学(D辑), 2004, 34(8):687-697.
[12]杜利林,耿元生,杨崇辉,等.扬子地台西缘康定群的再认识:来自地球化学和年代学证据[J].地质学报, 2007, 81(11):1562-1577.
[13]耿元生,杨崇辉,王新社,等.扬子地台西缘结晶基底时代[J].高校地质学报, 2007, 13(3):429-441.
[14]范晨子,胡明月,赵令浩,等.锆石铀-铅定年激光剥蚀-电感耦合等离子体质谱原位微区分析进展[J].岩矿测试, 2012, 31(1):29-46.
[15]李怀坤,耿建珍,郝爽,等.用激光烧蚀多接收器等离子体质谱仪(LA-MC-ICPMS)测定锆石UPb同位素年龄的研究[J].矿物学报, 2009,(增刊):600-601.
[16]Ludwig K R. A Geochronological Toolkit for Microsoft Excel[M]. Berkeley:Berkeley Geochronology Center Special Publication,2003, 49(2):1-56.
[17]刘建辉,刘敦一,张玉海,等.使用SHRIMP测定锆石铀-铅年龄的选点技巧[J].岩矿测试,2011, 30(3):265-268.
[18]姚建.攀枝花市大田地区混合岩成因研究[D].成都:成都理工大学, 2014.
[19]李莎莎.四川攀枝花(505)地区混合岩地球化学特征及其与铀成矿关系[D].成都:成都理工大学,2011.
[20]LI Z X, LI X H, KINNY P D, etal. The breakup of Rodinia:Did it start with a mantle plume beneath South China?[J]. EarthPlanet Sci Lett,1999, 173:171-181.
[21]LI Z X, LI X H, KINNY P D, etal. Doesit take a superplume to breakup a supercontinent?—a case for Rodinia[J]. GeolSocAust Abst, 2001, 65:74-77.
[22]LI Z X, LI X H, KINNY P D, etal.Geochronology of Neoproterozoic syn-rift magmatism in the Yangtze Craton, South China and correlations with other continents:evidence for amantle superplume that broke up Rodinia[J].Precambrian Research, 2003, 10(122):85-109.
[23]Li Xianhua, Zhu Weiguang, Zhong Hong, et al.The Tongde picrite dikes in the Western Yangtze Block:Evidence for ca.800 Ma mantle plume magmatism in South China during the breakup of Rodinia[J]. The Journal of Geology, 2010, 118(5):509-522.
[24]Lin Guangchun, Li Xianhua, Li Wuxian. SHRIMP U-Pb zircon age, geochemistry and Nd-Hf isotope of Neoproterozoic mafic dyke swarm in Western Sichuan:Petrogenesis and tectonic significance[J]:Science in China(Series D), 2007, 50(1):1-16.
[25]Zhu Weiguang, Zhong Hong, Deng Hailin, et al.SHRIMP zircon U-Pb geochronology, elemental and Nd isotopic geochemistry of the Neoproterozoic mafic dykes in the Yanbian area. SW China[J].Precambrian Research, 2008, 164(1/2):66-85.
[26]徐争启,欧阳鑫东,张成江,等.电子探针化学测年在攀枝花大田晶质铀矿中的应用及其意义[J].岩矿测试, 2017, 36(6):641-648.
[27]王红军,李巨初,薛钧月.康滇地轴元古代成矿作用对Rodinia事件的响应[J].地质学报,2009, 29(1):11-15.