西昆仑柳什塔格南二长花岗岩SHRIMP定年、地球化学特征及其地质意义
SHRIMP U-Pb Ages, Geochemical Characteristics and Geological Implications of the Monzonitic Granite at South Liushitage, West Kunlun
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摘要: 在柳什塔格南部的昆南增生楔中发育二长花岗岩体,侵入于古元古界双雁山岩群中深变质岩系中,其上被三叠纪阿他木帕下组不整合覆盖.该岩体主要为浅肉红色细粒二长花岗岩,局部地方渐变为花岗闪长岩或正长花岗岩,其内还发育少量后期的北东向辉长岩脉.对该岩体中的锆石进行了SHRIMP U-Pb测年,投点结果相对集中,位于谐和曲线附近,得到加权平均年龄为(455.9±7.4)Ma,为晚奥陶世早期,其岩石学、地球化学特征显示其为钙碱性序列,其高钾的含量和古老的锆石的存在说明该岩体的侵入背景为俯冲-同碰撞构造环境,间接证明了昆南有限洋盆在晚奥陶世已经闭合.该发现为昆仑造山带构造演化提供了新的地质依据,具有较大的地质意义.Abstract: The monzonite granite developed in the accretionary wedge in South Kunlun (South Liushitage) and intruded in the deep metamorphic rocks of Paleoproterozoic Shuangyanshan group, unconformably covered by the Triassic Atamupa formation. The rock is mainly light meat-red finegrained monzonitic granite, localized gradient to granodiorite or syenite granite, with also a small amount of gabbro occurred later in it. SHRIMP Zircon U-Pb dating is relatively concentrated and located near the concordia curve. With the weighted average age of 455.9±7.4 Ma, the monzonite granite should have formed in late Early Ordovician. The petrological, geochemical characteristics displayed as a sequence of calc-alkaline. The high potassium content and the presence of ancient zircons show that the rock is probably a result in subduction-collision tectonic environment, indirectly certificating that the limited ocean basin in South Kunlun has closed at the Late Ordovician. This finding has a great geological significance by providing new geological basis for the tectonic evolution of the Kunlun orogenic belt.
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Key words:
- monzonitic granite /
- SHRIMP Zircon U-Pb dating /
- Late Ordovician /
- Liushitage
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郑玉壮, 杨维文, 王腾. 新疆西昆仑早古生代侵入岩地球化学特征及地质意义 [J]. 西北地质, 2013, 46(4): 57-65.
Zheng Yuzhuang, Yang Weiwen, Wang Teng. Geochemistry and Geological Significance of Intrusive Rocks of Early Paleozoic inWestern Kunlun, Xinjiang [J]. Northwestern Geology, 2013, 46(4): 57-65.
李博秦, 姚建新, 王炬川, 等. 西昆仑柳什塔格峰西侧火山岩的特征、时代及地质意义 [J]. 岩石学报, 2007, 023(11): 2801-2810.
Li Boqin, Yao Jianxin, Wang Juchuan, et al. Composition, age and geological significance of the Liushitage volca-nics in West Kunlun mountains [J]. Acta Petrologica Sinica, 2007, 023(11): 2801-2810.
李荣社, 计文化, 赵振明, 等. 昆仑早古生代造山带研究进展 [J]. 地质通报, 2007, 26(4): 373-382.
Li Rongshe, Ji Wenhua, Zhao Zhenming, et al. Progress in the study or the Early Paleozoic Kunlun orogenlc belt [J]. Geological Bulletin of China, 2007, 26(4): 373-382.
王炬川, 韩芳林, 崔建堂, 等. 新疆于田普鲁一带早古生代花岗岩岩石地球化学特征及构造意义 [J]. 地质通报, 2003, 22(3): 170-181.
Wang juchuan, Han Fanglin, Cui Jiantan, et al. Geochemical Characteristics of Early Paleozoic granites in thePulu area, Yutian, Xinjiang and its tectonic significance [J]. Geological Bulletin of China, 2003, 22(3): 170-181.
李荣社, 计文化, 杨永成, 等. 昆仑山及邻区地质 [M]. 北京: 地质出版社, 2008.
Li Rong she, Ji Wen hua, Yang yongcheng, et al. Geology of Kunlun mountains and adgacent area [M]. Geolo-gical Publishing House, Beijing, 2008.
姜耀辉, 芮行健, 郭坤一, 等. 西昆仑造山带花岗岩形成的构造环境 [J]. 地球学报, 2000, 21(01): 23-25.
Jiang Yaohui, Rui Xingjian, Guo Kunyi, et al. Tectonic Environments of Granitoids in theWest Kunlun Orogenic Belt [J]. Acta Geoscientia Sinica, 2000, 21(1): 23-25.
姜耀辉, 芮行健, 郭坤一, 等. 西昆仑造山带花岗岩研究新进展 [J]. 火山地质与矿产, 2000,21(1): 61-63.
Jiang Yaohui, Rui Xingjian, Guo Kunyi, et al. New Progress of Granitoids in theWest Kunlun Orogenic Belt [J]. Volcanology & Mineral Resources, 2000, 21(01): 61-63.
周辉, 袁超. 西昆仑库地早古生代岩浆岩的物源与热源 [J]. 新疆地质, 2003, 21(1): 67-68.
Zhou Hui, Yuan Chao. Material and heat sources of the Early Paleozoic magmatic rocks in Kudi, Western Kunlun [J]. Xinjiang Geology, 2003, 21(1): 67-68.
崔建堂, 王炬川, 边小卫. 西昆仑康西瓦北侧蒙古包普守一带早古生代花岗岩锆石SHRIMP U-Pb测年 [J]. 地质通报, 2007, 26(6): 710-719.
Cui Jiantang, Wang Juchuan, Bian Xiaowei. Zircon SHRIMP U-Pb dating of Early Palezoic granite in the Meng gu bao-Pu shou area on the north ern side of Kangxiwar, West Kunlun [J]. Geological Bulletin of China, 2007, 26(6): 710-719.
王炬川, 崔建堂, 罗乾周, 等. 西昆仑康西瓦西部早古生代侵入岩的岩浆混合作用 [J]. 地质通报, 2006, 25(12): 1458-1468.
Wang Juchuan, Cui Jian tang, Luo Qianzhou, et al. Magmamingling of Early Paleozoic in tru sive rock s in wes-tern Kangxiwar, Western Kunlun, China [J]. Geolo-gical Bulletin of China, 2006, 25(12): 1458-1468.
柯珊, 莫宣学, 罗照华, 等. 塔什库尔干碱性杂岩的地球化学特征及其岩石成因 [J]. 岩石学报, 2006a, 22(4): 905-915.
KeShan, Mo Xuanxue, Luo Zhaohua, et al. Petrogenesis and geochemistry of Cenozoic Taxkorgan alkalic complex and its geological significance [J]. Acta Petrologica Sinica, 2006a, 22(4): 905-915.
Pearce J A, Harris N B W and Tindle A G. Trace element discrimination diagrams for the tecton ic interpretation of granitic rocks [J]. J. Petrol, 1984, 25: 956-983.
新疆西昆仑1:5万J44E021018、J44E022017、J44E022018、J44E023017、J44E023018五幅区域地质调查2013年简报 [R]. 2013.
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