Thermochronological Constraint to the Processes of the East Kunlun and Adjacent Areas in Mesozoic-Early Cenozoic
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摘要: 针对东昆仑及相邻地区研究较薄弱的中生代—新生代早期时段的构造过程提供了系列新的热年代学资料.不同热年代学方法综合揭示了东昆仑及相邻地区在中生代—新生代早期至少存在3次明显的热事件记录.第一次大约启动于200Ma的晚三叠世晚期, 并可能一直延续到早中侏罗世之交, 是一次具有广泛影响并奠定造山带区域构造格架的构造热事件.区域动力背景可能和南部羌塘地块与昆仑地块的碰撞、松潘—甘孜—巴颜喀拉浊积盆地闭合相关.第二次发生在大约130~150Ma的早白垩世, 并可能延续到早白垩世末, 主要表现为系列区域性NWW-SEE向的挤压性断裂活动, 可对应于白垩纪时期拉萨地块沿班公湖—怒江缝合带与欧亚大陆的增生拼贴事件.第三次为大约56~45Ma的古新世, 表现为一期伸展抬升.热年代学记录与零星保存的地质记录具有良好的匹配性, 并对构造过程提供了更确切的时间限定.Abstract: This paper displays some new thermochronological data on the tectonic processes of the East Kunlun and its adjacent areas in Mesozoic-Early Cenozoic, which were less investigated before. Three thermal events are revealed by different thermochronological methods. The first thermal event, which was a regional tectonic thermal event and established regional tectonic framework, started-up at about 200 Ma and lasted to the interim of the early-middle Jurassic. Its dynamics can be related to the closure of the Songpan-Ganzi-Bayan Har Triassic turbilite basin and the collision between the Qiangtang block and the Kumlun block. The second thermal event, mainly shows a series of NWW-SEE regional faults activity, occurred at about 130-150 Ma and lasted to about 100 Ma, the end of Early Cretaceous. The dynamics of this thermal event can be correspond to the collision between the Lhasa block and the Eurasia plate alone the Bangong-Nujiang suture zone. The last one happened at about 56-45 Ma, showing a extension-coursed uplift. The thermochronological records match well to the geological records which fragmentaryrily presented in the study area and provide a more certain constraint to the tectonic processes.
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Key words:
- East Kunlun /
- Mesozoic-Early Cenozoic /
- thermochronology.
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图 1 东昆仑中段地质简图 (图中方框示图4范围)
1.第四系;2.上三叠统 (八宝山组) —下侏罗统 (羊曲组) 陆相火山碎屑含煤建造;3.上二叠统 (格曲组) —中下三叠统 (洪水川组、闹仓坚沟组、希里可特组) 河流—滨浅海相砂砾岩、碳酸盐岩—半深海相碎屑复理石建造, 含火山岩;4.三叠系巴颜喀拉山群碎屑浊积岩;5.中下二叠统阿尼玛卿蛇绿混杂岩系;6.泥盆系—二叠系 (牦牛山组、哈拉郭勒组、浩特诺洼组) 陆相碎屑磨拉石建造、火山岩建造—浅海碳酸盐岩建造;7.奥陶系—志留系纳赤台岩群构造混杂岩系;8.中上元古界 (冰沟群和万宝沟群) 碳酸盐岩及玄武岩;9.太古界—元古界片麻岩、大理岩和石英岩;10.不同时代花岗质侵入体;11.超镁铁岩12.主要断裂;13.巴颜喀拉山群碎屑锆石裂变径迹样品取样点及样品编号
Fig. 1. Simplified geological map of the middle eastern Kunlun
图 4 东昆仑香日德西南部布尔汗布达山北坡地质地貌简图及裂变径迹采样点分布
1.第四系;2.下古生界纳赤台岩群;3.中元古界小庙岩群;4.古元古界白沙河岩群;5.燕山期花岗岩;6.海西—燕山期花岗岩或花岗闪长岩;7.正断层; 8.性质不明断层;9.主要山脊线;10.河流水系及流向;11.制高点及标高;12.磷灰石裂变径迹年龄样品采样点、样号、样点标高及年龄值
Fig. 4. Sketch map showing geology, landform and distribution of fission-track samples, Southwest Xiangride area, eastern Kunlun
表 1 三叠纪巴颜喀拉山群砂岩碎屑锆石裂变径迹年龄
Table 1. Detrital zircon fission-track ages of sandstones of the Bayan Har Group
表 2 红石山早中二叠世阿尼玛卿构造混杂岩系片理化变玄武岩 (BP16-27) 锆石U-Pb SHRIMP年龄分析结果
Table 2. Zircon U-Pb SHRIMP age dating results of foliated basalt (sample BP16-27) from the early-middle Permian A'nymaqen mélange at the Hongshishan area
表 3 布尔汗布达山北坡基岩岩石的磷灰石裂变径迹测试结果
Table 3. Results of apatite fission-track age dating of the bedrocks from the north slope of the Buerhanbuda Shan, earstern Kunlun
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Arnaud, N., Tapponnier, P., Wang, S., et al., 2003. Evidence for Mesozoic shear along the western Kunlun and Altyn-Tagh fault, northern Tibet (China). J. Geophys. Res., 108 (2053): 12-1-12-27. Bruguier, O., Lancelot, J. R., Malavieille, J., 1997. U-Pb dating on single detrital zircon grains from the Triassic Songpan-Ganzi flysch (Central China): Provenance and tectonic correlations. Earth and Planetary Science Letters, 152: 217-231. doi: 10.1016/S0012-821X(97)00138-6 Burchfiel, B. C., Chen, Z., Liu, Y., et al., 1995. Tectonics of the Longmen Shan and adjacent regions, Central China. International Geology Review, 37 (8): 661-735. doi: 10.1080/00206819509465424 Chen, S., Wilson, C. J. L., 1996. Emplacement of the Longmen Shan thrust-Nappe belt along the eastern margin of the Tibetan plateau. Journal of Structural Geology, 18 (4): 413-430. Chen, S., Wilson, C. J. L., Deng, Q., et al., 1994. Active faulting and block movement associated with large earthquakes in the Min Shan and Longmen Mountains, northeastern Tibetan Plateau. J. Geophys. Res., 99: 24025-24038. doi: 10.1029/94JB02132 Chen, W., Arnaud, N., 1997. Isotope geochronology study for“POG type”granite in Bayan Har Terrain, Qinghai-Xizang plateau, China. Acta Geoscientia Sinica, 18 (3): 261-266 (in Chinese with English abstract). Cui, Z. J., Gao, Q. Z., Liu, G. N., et al., 1996. Planation surfaces, palaeokarst and uplift of Xizang (Tibet) plateau. Science in China (Ser. D), 39 (4): 391-400. Cui, Z. J., Wu, J. Q., Liu, G. N., et al., 1998. On Kunlun-Yellow river tectonic movement. Science in China (Ser. D), 41 (6): 592-600. doi: 10.1007/BF02878741 Guo, Z. F., Deng, J. F., Xu, Z. Q., et al., 1998. Late Palaeozoic-Mesozoic intracontinental orogenic processes and intermediate-Acidic igneous rocks from the eastern Kunlun mountains of northwestern China. Geoscience, 12 (3): 344-352 (in Chinese with English abstract). Jiang, C. F., Yang, J. S., Feng, B. C., et al., 1992. Opening and closing tectonics of Kunlun mountains. Geological Publishing House, Beijing (in Chinese). Jolivet, M., Brunel, M., Seward, D., et al., 2001. Mesozoic and Cenozoic tectonics of the northeast edge of the Tibetan plateau: Fission-track constraints. Tectonophysics, 343 (1-2): 111-134. doi: 10.1016/S0040-1951(01)00196-2 Li, C. A., Yin, H. F., Yu, Q. W., 2000. Evolution of drainage systems and its development trend in connection with tectonic uplift of eastern Kunlun Mt. Chinese Science Bulletin, 45 (20): 1904-1908. doi: 10.1007/BF02886304 Li, H. B., Yang, J. S., 2004. Evidence for Cretaceous uplift of the Qinghai-Tibetan Plateau. Earth Science Frontiers, 11 (4): 345-359 (in Chinese with English abstract). Li, J. J., Fang, X. M., Ma, H. Z., et al., 1996. Geomorphological and environmental evolution in the upper reaches of the Yellow river during the late Cenozoic. Science in China (Ser. D), 39 (4): 380-390. Liu, Y. J., Genser, J., Neubauer, F., et al., 2005.40Ar/39Ar mineral ages from basement rocks in the Eastern Kunlun Mountains, NW China, and their tectonic implications. Tectonophysics, 398: 199- 224. Liu, Y. J., Ye, H. W., Ge, X. H., et al., 2000. Laser probe 40Ar/39Ar dating of micas on the deformed rocks from Altyn fault. Chinese Science Bulletin, 45 (19): 2101-2104 (in Chinese). doi: 10.1360/csb2000-45-19-2101 Mock, C., Arnaud, N. O., Cantagrel, J. M., 1999. An early unroofing in northeastern Tibet? Constraints from 40Ar/39Ar thermochronology on granitoids from the eastern Kunlun range (Qianghai, NW China). Earth and Planetary Science Letters, 171: 107-122. doi: 10.1016/S0012-821X(99)00133-8 Pan, G. T., Chen, Z. L., Li, X. Z., et al., 1997. Geological-Tectonic evolution in the eastern Tethys. Geological Publishing House, Beijing (in Chinese). Pan, Y. S., Zhou, W. M., Xu, R. H., et al., 1996. Geological characteristics and evolution of the Kunlun mountains region during the Early Paleozoic. Science in China (Ser. D), 13 (4): 337-347. Shi, Y. F., Li, J. J., Li, B. Y., et al., 1999. Uplift of the Qinghai-Xizang (Tibetan) plateau and East Asia environmental change during late Cenozoic. Acta Geographica Sinica, 54 (1): 10-54 (in Chinese with English abstract). Wang, G. C., Hou, G. J., Zhang, K. X., et al., 2002. Mountain building and its dynamic transition since Middle Pleistocene in the east of eastern Kunlun, northeast Tibetan plateau. Earth Science—Journal of China University of Geosciences, 27 (1): 4-12 (in Chinese with English abstract). Wang, G. C., Jia, C. X., Zhu, Y. H., et al., 2004. New results and major progress in regional geological survey of the Alag lake sheet. Geological Bulletin of China, 23 (5-6): 549-554 (in Chinese with English abstract). Wang, G. C., Xiang, S. Y., John, I. Garver, et al., 2003. Uplift and exhumation during Mesozoic in Halaguole-Hatu area, east segment of the eastern Kunlun-Evidence from zircon and apatite fission-track ages. Earth Science—Journal of China University of Geosciences, 28 (6): 645-652 (in Chinese with English abstract). Worley, B. A., Wilson, C. J. L., 1996. Deformation partitioning and foliation reactivation during transpressional orogenesis, an example from the Central Longmen Shan, China: Journal of Structural Geology, 18 (4): 395-411. Wu, Y. Q., Cui, Z. J., Liu, G. N., et al., 2001. Quaternary geomorphological evolution of the Kunlun Pass area and uplift of the Qinghai-Xizang (Tibet) Plateau. Geomorphology, 36: 203-216. doi: 10.1016/S0169-555X(00)00057-X Yin, A., Harrison, T. M., 2000. Geologic evolution of the Himalayan-Tibetan orogen. Annual Review of Earth and Planetary Sciences, 28: 211-280. doi: 10.1146/annurev.earth.28.1.211 Yuan, W. M., Zhang, X. T., Dong, J. Q., et al., 2003. A new vision of the intracontinental evolution of the eastern Kunlun mountains, northern Qinghai-Tibet plateau, China. Radiation Measurements, 36: 357-362. doi: 10.1016/S1350-4487(03)00151-3 陈文, Arnaud, N., 1997. 巴颜喀拉地体POG型花岗岩同位素年代学研究. 地球学报, 18 (3): 261-266. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXB703.005.htm 崔之久, 高全洲, 刘耕年, 等, 1996. 夷平面、古岩溶与青藏高原隆升. 中国科学 (D辑), 26 (4): 378-386. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK199604014.htm 崔之久, 伍永秋, 刘耕年, 等, 1998. 关于“昆仑-黄河运动”. 中国科学 (D辑), 28 (1): 53-59. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK199801009.htm 郭正府, 邓晋福, 许志琴, 等, 1998. 青藏东昆仑晚古生代末—中生代中酸性火成岩与陆内造山过程. 现代地质, 12 (3): 344-352. https://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ803.006.htm 姜春发, 杨经绥, 冯秉贵, 等, 1992. 昆仑开合构造. 北京: 地质出版社. 李长安, 殷鸿福, 于庆文, 1999. 东昆仑山构造隆升与水系演化及其发展趋势. 科学通报, 44 (2): 211-213. doi: 10.3321/j.issn:0023-074X.1999.02.023 李海兵, 杨经绥, 2004. 青藏高原北部白垩纪隆升的证据. 地学前缘, 11 (4): 345-359. doi: 10.3321/j.issn:1005-2321.2004.04.002 李吉均, 方小敏, 马海州, 等, 1996. 晚新生代黄河上游地貌演化与青藏高原隆起. 中国科学, 26 (4): 316-322. doi: 10.3321/j.issn:1006-9267.1996.04.005 刘永江, 叶慧文, 葛肖虹, 等, 2000. 阿尔金断裂变形岩激光微区40Ar/39Ar年龄. 科学通报, 45 (19): 2101-2104. doi: 10.3321/j.issn:0023-074X.2000.19.016 潘桂堂, 陈智梁, 李兴振, 等, 1997. 东特提斯地质构造形成演化. 北京: 地质出版社. 潘裕生, 周伟明, 许荣华, 等, 1996. 昆仑早古生代地质特征与演化. 中国科学 (D辑), 26 (4): 302-307. 施雅凤, 李吉均, 李炳元, 等, 1999. 晚新生代青藏高原的隆升与东亚环境变化. 地理学报, 54 (1): 10-54. https://www.cnki.com.cn/Article/CJFDTOTAL-DLXB901.001.htm 王国灿, 侯光久, 张克信, 等, 2002. 东昆仑东段中更新世以来的成山作用及其动力转换. 地球科学——中国地质大学学报, 27 (1): 4-12. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200201001.htm 王国灿, 贾春兴, 朱云海, 等, 2004. 阿拉克湖幅地质调查新成果及主要进展. 地质通报, 23(5-6):549-554. http://www.cnki.com.cn/Article/CJFDTotal-ZQYD2004Z1025.htm 王国灿, 向树元, John, I. Garver, 等, 2003. 东昆仑东段哈拉郭勒-哈图一带中生代的岩石隆升剥露—锆石和磷灰石裂变径迹年代学证据. 地球科学———中国地质大学学报, 28(6):645-652.