40Ar/39Ar laser dating of the Zongwulong ductile shear zone in northeastern Tibetan Plateau: Constraints on the time of Indosinian orogeny
-
摘要:
青藏高原东北缘的宗务隆构造带位于柴达木地块与南祁连地块之间，位置极为重要，其中发育的韧性剪切带变形特征和形成时代对于理解该构造带的构造属性具有重要的制约意义。详细的野外构造解析，显微构造解析与年代学研究表明，宗务隆剪切带发育走向NWW-SEE向糜棱面理，其上发育NWW-SEE向缓倾的拉伸线理，指示该剪切带逆冲-走滑剪切的特征。宏观尺度上可见由于剪切作用形成的不对称褶皱、旋转碎斑、构造透镜体及褶劈理等变形形迹；显微镜下可观察到云母鱼、S-C组构、σ型残斑及石英动态重结晶、拔丝构造等变形现象，指示该韧性剪切变形的温度在300~400℃。对剪切带同构造变形的白云母和黑云母进行了40Ar/39Ar同位素年代学分析，2个样品的坪年龄分别为（245.8±1.7）Ma、（238.5±2.6）Ma，指示了该剪切变形发生在早-中三叠世期间。结合对区域地质、岩石学等资料的综合分析，该期韧性剪切变形年龄代表了宗务隆构造带印支期造山作用的时间，这期造山活动可能与宗务隆有限洋盆闭合后，南祁连地块与欧龙布鲁克地块的斜向碰撞有关。
Abstract:The Zongwulong tectonic belt (ZTB) is located between the northern Qaidam tectonic belt and the south Qilian orogenic belt and contains Late Paleozoic and Early-Middle Triassic strata. Structural features and geochronology of the Zongwulong ductile shear zone have key implications for the tectonic property of the ZTB. This study integrated field structure, microscopic structure and 40Ar/39Ar laser probe analysis. The shear zone strikes ~NEE-SWW and dips at a high angle, with a NWW-SEE trending and W-E stretching lineation, indicating the shear zone as a thrust-slip shear ductile shear. The asymmetric folds, rotating porphyroclast, structural lens and crenulation cleavage can be seen in the field. Mica fish, S-C fabrics, σ type quartz porphy roblasts and quartz wire drawing structure can also be observed under the microscope, indicating that the strike-slip related ductile deformation and mylonitization occurred under low-grade greenschist facies conditions at temperatures of 300℃ -400℃. The highly deformed mylonite schist yielded 40Ar/39Ar ages (245.8±1.7)Ma and (238.5±2.6)Ma for muscovite and biotite, respectively, indicating that the shear deformation occurred during the Early-Mid Triassic. Combined with a comprehensive analysis of regional geology and petrology, the authors hold that the age of ductile shear deformation represents the time of Indosinian orogeny in the ZTB. The orogenic activity was probably related to the oblique collision between the South Qilian block and the Oulongbuluke block after the closure of the ocean basin.
-
-
表 1 样品CD15-006-1白云母和样品CD15-043-7黑云母40Ar/39Ar阶段升温加热分析结果
Table 1. The muscovite (sample CD15-006-1) and biotite (sample CD15-043-7) 40Ar/39Ar stage heating analysis result
下载: 导出CSV
-
Chen Nengsong, Gong Songlin, Sun Min, Li Xiaoyan, Xia Xiaoping, Wang Qinyan, Wu Fuyuan, Xu Ping, 2009. Precambrian evolution of the Quanji Block, northeastern margin of Tibet:Insights from zircon U-Pb and Lu-Hf isotope compositions[J]. Journal of Asian Earth Sciences, 35(3/4):367-376. http://www.sciencedirect.com/science/article/pii/S1367912008001612
Chen Wen, Zhan Yan, Zhang Yueqiao, Jin Guishan, Wang Qingli, 2006. Late Cenozoic episodic uplifting in southeastern part of the Tibetan plateau-evidence from Ar-Ar thermochronology[J]. Acta Petrologia Sinica, 22(4):867-872(in chinese with English abstract). http://adsabs.harvard.edu/abs/2009gecas..73r1512z
Da Liangchao, Niu Manlan, Li Xiucai, Han Yu, Wu Qi, Yan Zhen, Zhao Qiqi. 2017. Tectonic deformation characteristics of the L tectonites in Erlangdong area at the northern margin of Qaidam Basin and its geological significance[J]. Chinese Journal of Geology, 52(4):1038-1057(in Chinese with English abstract). http://www.researchgate.net/publication/322137098_Tectonic_deformation_characteristics_of_the_L_tectonites_in_Erlangdong_area_at_the_northern_margin_of_Qaidam_Basin_and_its_geological_significance
Guo Anlin, Zhang Guowei, Qiang Juan, Sun Yangui, Li Guang, Yao Anping. 2009. Indosinian Zongwulong orogenic belt on the northeastern margin of the Qinghai-Tibet plateau[J]. Acta Petrologica Sinica, 25(1):1-12(in Chinese with English abstract).
Hames W E, Bowring S A.1994. An empirical evaluation of the argon diffusion geometry in muscovite[J]. Earth & Planetary Science Letters, 124(1/4):161-169. http://www.sciencedirect.com/science/article/pii/0012821X94000794
Hao Guojie, Lu Songnian, Wang Huichu, Xin Houtian, Li Huaikun.2004. The Pre-Devonian tectonic framework in the northern margin of Qaidam basin and geological evolution of Olongbuluck palaeo-block[J]. Earth Science Frontiers, 11(3):115-122(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DXQY200403016.htm
Harrison T M, Duncan I, Mcdougall I. 1985. Diffusion of 40Ar in biotite:Temperature, pressure and compositional effects[J]. Geochimica et Cosmochimica Acta, 49(11):2461-2468. doi: 10.1016/0016-7037(85)90246-7
Liu Yongjian, Franz Neubauer, Li Weimin, Hohann Genser, Li Wei. 2012. Tectono-thermal events of the Northern Qaidam margin-southern Qilian area, western China[J]. Journal of Jilin University(Earth Science Edition), 42(5):1317-1329(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-CCDZ201205006.htm
Lu Songnian, Wang Huichu, Li Huaikun, Yuan Guibang, Xin Houtian, Zheng Jiankang. 2002. Redefinition of the"Dakendaban Group" on the northern margin of the Qaidam basin[J]. Geological Bulletin of China, 21(1):19-23(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZQYD200201003.htm
Ludwig K R. 2001. User's manual for Isoplot/Ex (rev. 2.49): A Geochronological Toolkit for Microsoft Excel[R]. Berkeley Geochronology Centre, Special Publication, 1a, 55.
Mcdougall I, Harrison T M. 1999. Geochronology and Thermochronology by the 40Ar/39Ar Method[M]. Oxford University Press:34-59.
Meng Fanchong, Zhang Jianxin, Yang Jingsui. 2005. Tectono-thermal event of post-HP/UHP metamorphism in the Xitieshan area of the North Qaidam Moutains, western China:Isotopic and geochemical evidence of granite and gneiss[J]. Acta Petrologica Sinica, 21(1):45-56(in Chinese with English abstract) http://en.cnki.com.cn/Article_en/CJFDTOTAL-YSXB200501005.htm
Pan Guitang, Li Xingzhen, Wang Liquan, Chen Zhiliang. 2002. Preliminary division of tectonic units of the Qinghai-Tibet Plateau and its adjacent regions[J]. Geological Bullitin of China, 21(11):701-707(in Chinese with English abstract) http://www.researchgate.net/publication/284870409_Preliminary_division_of_tectonic_units_of_the_Qinghai-Tibet_Plateau_and_its_adjacent_regions
Passchier C W, Trouw R A J. 2005. Microtectonics[M]. Springer Berlin Heidelberg.
Peng Yuan, Ma Yinsheng, Liu Chenglin, Li Zongxing, Sun Jiaopeng, Shao Pengcheng. 2016. Geological characteristics and tectonic significance of the Indosinian granodiorites from the Zongwulong tectonic belt in North Qaidam[J]. Earth Science Frontiers, 23(2):206-221(in Chinese with English abstract). http://www.researchgate.net/publication/301555200_Geological_characteristics_and_tectonic_significance_of_the_Indosinian_granodiorites_from_the_Zongwulong_tectonic_belt_in_North_Qaidam
Qiu Shidong, Gu Pingyang, Pang Xinyu, Dong Zengchan, Zha Xianfeng, Zha Fangyong, Chen Ruiming, Zhuang Yujun. 2015. Zircon MC-LA-ICP-MS U-Pb dating, geochemistry and geological significance of gneissic quartz diorite in Northern Lenghu, Qinghai[J]. Geological Review, 61(4):948-960(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-DZLP201504023.htm
Song Shuguang, Zhang Lifei, Niu Yaoling, Song Biao, Liu Dunyi. 2004. Early Paleozoic plate-tectonic evolution and deep continental subduction on the northern margin of the Qinghai-Tibet Plateau[J]. Geological Bullitin of China, 23(9):918-925(in Chinese with English abstract). http://www.zhangqiaokeyan.com/academic-journal-cn_geological-bulletin-china_thesis/0201252292606.html
Stipp M, Stünitz H, Heilbronner R, Schmid S M, 2002. The eastern Tonale fault zone:A 'natural laboratory' for crystal plastic deformation of quartz over a temperature range from 250 to 700℃[J]. Journal of Structural Geology, 24(12):1861-1884. doi: 10.1016/S0191-8141(02)00035-4
Wang Huichu, Lu Songnian, Yuan Guibang, Xin Houtian, Zhang Baohua, Wang Qinghai, Tian Qi. 2003. Tectonic setting and age of the "Tanjianshan Group" on the northern margin of the Qaidam basin[J]. Geological Bulletin of China, 22(7):487-493(in Chinese with English abstract). http://www.zhangqiaokeyan.com/academic-journal-cn_geological-bulletin-china_thesis/0201252293455.html
Wang Suli, Zhou Lifa, 2016. LA-ICP-MS zircon U-Pb dating, geochemistry and tectonic implication of the bojite in the Zongwulong Mountain[J]. Journal of Northwest University(Natural Science Edition), 46(5):716-724(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-XBDZ201605018.htm
Wang Yizhi, Bai Yongshan, 2001. Geological characteristics of Tianjunnanshan ophiolite in Qinghai and its forming environment[J]. Geology of Qinghai, 1:29-35(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-GTJL200101005.htm
Wu Cailai, Lei Min, Wu Di, Li Tianxiao. 2016. Zircon SHRIMP dating and genesis of granites in Wulan area of Northern Qaidam[J]. Acta Geoscientica Sinica 37(4):493-516(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXB201604015.htm
Xu Wei, Sun Zhiming, Pei Junling, Pan Jiawei, Li Haibing, Li Aozhu, Zhao Yue, Ren Xiaojuan. 2011. New Late Permian paleomagnetic results from Qaidam block and tectonic implications[J]. Acta Petrologica Sinica, 27(11):3479-3486(in Chinese with English abstract). http://adsabs.harvard.edu/abs/2011agufmgp11a0998s
Yang Chao, Chen Qinghua, Wang Guanmin, Pang Xiaojun, Ma Tingting. 2010. Sedimentary and tectonic evolution of Qaidam areas in Late Paleozoic[J]. Journal of China University of Petroleum, 34(5):38-43(in Chinese with English abstract). http://www.researchgate.net/publication/286885993_Sedimentary_and_tectonic_evolution_of_Qaidam_areas_in_Late_Paleozoic
Yang Jingsui, Wang Xibin, Shi Rendeng, Xu Zhiqin, Wu Cailai. 2004. The Dur'ngoi ophiolite in East Kunlun, northern Qinghai-Tibet Plateau:A fragment of paleo-Tethyan oceanic crust[J]. Geology in China, 31(3):225-239(in Chinese with English abstract). http://www.cnki.com.cn/Article/CJFDTotal-DIZI200403000.htm
Zhang Guibin, Zhang Lifei, Christy Andrew G. 2013. From oceanic subduction to continental collision:An overview of HP-UHP metamorphic rocks in the North Qaidam UHP belt, NW China[J]. Journal of Asian Earth Sciences, 63:98-111. doi: 10.1016/j.jseaes.2012.07.014
Zhang Yan, Chen Wen, Chen Kelong, Liu Xinyu. 2006. Study on the Ar-Ar age spectrum of diagenetic I/S and the mechanism of 39Ar recoil loss——Examples from the clay minerals of P-T boundary in Changxing, Zhejiang Province[J]. Geological Review, 52(4):556-561(in Chinese with English abstract). http://www.researchgate.net/publication/306159693_Study_on_the_Ar-Ar_age_spectrum_of_diagenetic_IS_and_the_mechanism_of_39Ar_recoil_loss_Examples_from_the_clay_minerals_of_P-T_boundary_in_Changxing_Zhejiang_Province
Zhang Yu, Pei Xianzhi, Li Ruibao, Liu Chenjun, Chen Youxin, Li Zuochen, Wang Xin, Hu Chenguang, Yan Quanzhi, Peng Sizhong, Chen Guochao. 2017. Zircon U-Pb geochronology, geochemistry of the Alasimu gabbro in eastern section of East Kunlun Mountains and the closing time of Paleoocean basin[J]. Geology in China, 44(3):526-540(in Chinese with English abstract). http://www.researchgate.net/publication/322733559_Zircon_U-Pb_geochronology_geochemistry_of_the_Alasimu_gabbro_in_eastern_section_of_East_Kunlun_Mountains_and_the_closing_time_of_Paleo-ocean_basin
Zhu Guang, Wang Yongsheng, Liu Guosheng, Niu Manlan, Xie Chenglong, Li Changcheng, 2005. 40Ar/39Ar dating of strike-slip motion on the Tan-Lu fault zone, East China[J]. Journal of Structural Geology, 27(8):1379-1398. doi: 10.1016/j.jsg.2005.04.007
陈文, 张彦, 张岳桥, 金贵善, 王清利.2006.青藏高原东南缘晚新生代幕式抬升作用的Ar-Ar热年代学证据[J].岩石学报, 22(4):867-872. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200604010.htm
笪梁超, 牛漫兰, 李秀财, 韩雨, 吴齐, 闫臻, 赵齐齐.2017.柴北缘二郎洞地区L构造岩变形特征及其地质意义[J].地质科学, 52(4):1038-1057.
郭安林, 张国伟, 强娟, 孙延贵, 李广, 姚安平.2009.青藏高原东北缘印支期宗务隆造山带[J].岩石学报, 25(1):1-12. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200901002.htm
郝国杰, 陆松年, 王惠初, 辛后田, 李怀坤. 2004.柴达木盆地北缘前泥盆纪构造格架及欧龙布鲁克古陆块地质演化[J].地学前缘, 11(3):115-122. doi: 10.3321/j.issn:1005-2321.2004.03.013
胡玲.2009.变形显微构造识别手册[M].北京:地质出版社.
刘永江, Franz Neubauer, 李伟民, Johann Genser, 李伟. 2012.柴北缘-南祁连地区构造热事件[J].吉林大学学报(地球科学版), 42(5):1317-1329. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201205006.htm
陆松年, 王惠初, 李怀坤, 袁桂邦, 辛后田, 郑健康. 2002.柴达木盆地北缘"达肯大坂群"的再厘定[J].地质通报, 21(1):19-23. doi: 10.3969/j.issn.1671-2552.2002.01.004
孟繁聪, 张建新, 杨经绥.2005.柴北缘锡铁山早古生代HP/UHP变质作用后的构造热事件——花岗岩和片麻岩的同位素与岩石地球化学证据[J].岩石学报, 21(1):45-56. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200501005.htm
潘桂棠, 李兴振, 王立全, 丁俊, 陈智粱.2002.青藏高原及邻区大地构造单元初步划分[J].地质通报, 21(11):701-707. doi: 10.3969/j.issn.1671-2552.2002.11.002
彭渊, 马寅生, 刘成林, 李宗星, 孙娇鹏, 邵鹏程.2016.柴北缘宗务隆构造带印支期花岗闪长岩地质特征及其构造意义[J].地学前缘, 23(2):206-221. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201602024.htm
青海省地质矿产局.1991.青海省区域地质志[M].北京:地质出版社, 1-662.
邱士东, 辜平阳, 庞新愉, 董增产, 查显峰, 查方勇, 陈锐明, 庄玉军. 2015.青海冷湖北片麻状石英闪长岩的MC-LA-ICP-MS锆石U-Pb年龄、地球化学特征及地质意义[J].地质论评, 61(4):948-960. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201504023.htm
宋述光, 张立飞, Niu Y., 宋彪, 刘墩一. 2004.青藏高原北缘早古生代板块构造演化和大陆深俯冲[J].地质通报, 23(9):918-925. doi: 10.3969/j.issn.1671-2552.2004.09.014
王惠初, 陆松年, 袁桂邦, 辛后田, 张宝华, 王青海, 田琪. 2003.柴达木盆地北缘滩间山群的构造属性及形成时代[J].地质通报, 22(7):487-493. doi: 10.3969/j.issn.1671-2552.2003.07.005
王苏里, 周立发. 2016.宗务隆山角闪辉长岩LA-ICP-MS锆石U-Pb定年、地球化学特征及其地质意义[J].西北大学学报(自然科学版), 46(5):716-724. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDZ201605018.htm
王毅智, 拜永山, 陆海莲. 2001.青海天峻南山蛇绿岩的地质特征及其形成环境[J].青海地质, (1):29-35. https://www.cnki.com.cn/Article/CJFDTOTAL-GTJL200101005.htm
吴才来, 雷敏, 吴迪, 李天啸. 2016.柴北缘乌兰地区花岗岩锆石SHRIMP定年及其成因[J].地球学报, 37(4):493-516. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXB201604015.htm
许伟, 孙知明, 裴军令, 潘家伟, 李海兵, 李傲竹, 赵越, 任晓娟. 2011.青藏高原北部柴达木块体晚二叠世古地磁结果及其构造意义[J].岩石学报, 27(11):3479-3486. https://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201111026.htm
许志琴. 1997.中国主要大陆山链韧性剪切带及动力学[M].北京:地质出版社.
杨超, 陈清华, 王冠民, 庞小军, 马婷婷. 2010.柴达木地区晚古生代沉积构造演化[J].中国石油大学学报(自然科学版), 34(5):38-43. https://www.cnki.com.cn/Article/CJFDTOTAL-SYDX201005009.htm
杨经绥, 王希斌, 史仁灯, 许志琴, 吴才来. 2004.青藏高原北部东昆仑南缘德尔尼蛇绿岩:一个被肢解了的古特提斯洋壳[J].中国地质, 31(3):225-239. doi: 10.3969/j.issn.1000-3657.2004.03.001 http://geochina.cgs.gov.cn/geochina/ch/reader/view_abstract.aspx?file_no=20040301&flag=1
张雪婷. 2007.青海省区域地质概论[M].北京:地质出版社.
张彦, 陈文, 陈克龙, 刘新宇.2006.成岩混层(I/S)Ar-Ar年龄谱型及39Ar核反冲丢失机理研究——以浙江长兴地区P-T界线粘土岩为例[J].地质论评, 52(4):556-561. doi: 10.3321/j.issn:0371-5736.2006.04.015
张玉, 裴先治, 李瑞保, 刘成军, 陈有炘, 李佐臣, 王兴, 胡晨光, 颜全治, 彭思钟. 2017.东昆仑东段阿拉思木辉长岩锆石U-Pb年代学、地球化学特征及洋盆闭合时限界定[J].中国地质, 44(3):526-540. http://geochina.cgs.gov.cn/geochina/ch/reader/view_abstract.aspx?file_no=20170310&flag=1
-
图(7)
表(1)
计量
- 文章访问数: 3491
- PDF下载数: 141
- 施引文献: 0