地震地质 ›› 2014, Vol. 36 ›› Issue (1): 1-13.DOI: 10.3969/j.issn.0253-4967.2014.02.001

• 研究论文 • 上一篇    下一篇

库木库里背斜活动性初步研究

孙浩越1, 何宏林1, 付碧宏2, 杨顺虎2, 白濱吉起3, 池田安隆3, 狩野谦一4, 越後智雄5   

  1. 1 中国地震局地质研究所, 活动构造与火山重点实验室, 北京 100029;
    2 中国科学院地质与地球物理研究所, 地球深部研究重点实验室, 北京 100029;
    3 东京大学地球与行星科学系, 东京 113-0033;
    4 静冈大学地球科学研究所, 静冈 422-8529;
    5 地域·地盤·環境研究所, 大阪 550-0012
  • 收稿日期:2013-04-06 修回日期:2013-08-14 出版日期:2014-03-30 发布日期:2014-04-08
  • 通讯作者: 何宏林,研究员,E-mail:honglin@ies.ac.cn
  • 基金资助:
    日本學術振興會“チベット高原の拡大過程に関する研究”(22300314)资助

A PRELIMINARY APPROACH TO THE ACTIVITY OF KUMUKOL ANTICLINE

SUN Hao-yue1, HE Hong-lin1, FU Bi-hong2, YANG Shun-hu2, Yoshiki SHIRAHAMA3, Yasutakyr IKEDA3, Kenichi KANO4, Tomoo ECHIGO5   

  1. 1 Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    2 State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
    3 Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033, Japan;
    4 Institute of Sciences, Shizuoka University, Shizuoka 422-8529, Japan;
    5 Geo-Research Institute, Osaka 550-0012, Japan
  • Received:2013-04-06 Revised:2013-08-14 Online:2014-03-30 Published:2014-04-08

摘要: 库木库里盆地位于青藏高原北缘,与柴达木盆地一山之隔,是二者的过渡地带,也是高原主体部分向NE扩展的前缘地区;现今构造表现为被3条大型活动构造带(走滑的阿尔金断裂带、东昆仑断裂带和逆冲的祁漫塔格褶皱逆冲系)所夹持。因此,该盆地对于研究青藏高原北缘的构造活动性、活动历史,探讨高原的扩展模式具有十分重要的意义。虽然库木库里盆地南、北两侧均发育活动性很强的大型走滑断裂,但是在盆地中央发育1条大型背斜,走向NWW-SEE,与祁漫塔格褶皱逆冲系和柴达木盆地内的褶皱构造走向一致,说明盆地目前遭受NNE向的挤压。通过对盆地地形横、纵剖面和阶地展布形态的分析,得出背斜有自西向东扩展变形的特征;野外调查和测年结果显示,背斜东段冰川融水形成了大型冰水扇,形成年龄为(87.09±2.31)~(102.4±3.7)ka,进而获得背斜东段自晚更新世以来平均隆升速率的最大值为(2.78±0.28)~(3.28±0.28)mm/a。库木库里盆地整体的活动性很强,在构造上与其北边的柴达木盆地类似,都受控于阿尔金断裂南侧的NNE向的区域挤压作用。

关键词: 库木库里背斜, 侧向扩展, 晚更新世, 隆升速率

Abstract: Kumukol Basin, located at the north margin of the Tibetan plateau, is separated from the Qaidam Basin by the Qimantag Range geographically. It is the transitional region between the Tibetan plateau and Qaidam Basin, and also the leading edge of the growing main body of the plateau. Nowadays, East Kunlun Fault and Altyn Tagh Fault, two significant strike-slip faults of Tibetan plateau, as well as the compressional Qimantag folding thrust system, delimit the southern, western and northern borders of the basin, respectively. Therefore, the study on the tectonic deformation and tectonic evolution of the basin will play an important role in understanding the style and mechanism of the eastward expanding of Tibetan plateau.
Although Kumukol Basin is delimited by strongly active strike-slip faults, a very large anticline is growing in the basin, with a similar strike of NWW-SEE to the Qimantag folding thrust system and the folds in Qaidam Basin, such as Youshashan fold, suggesting that the basin is compressional. In this study, the lateral growth of this anticline is revealed by the analysis on the topographic profiles and distribution of terraces. A conclusion, as well, is made that the large proluvial fan at the east segment of the anticline is a result of the glacier melt water based on the field survey and dating of terrace samples. According to the OSL and 10Be exposure ages, the age of the fan is 87.09±2.31ka~102.4±3.7ka, and accordingly, we can get a maximum uplift rate of(2.78±0.28)mm/a~(3.28±0.28)mm/a for the anticline since late Pleistocene. Tectonically, Kumukol Basin is highly similar to Qaidam Basin on its north, both are strongly active and controlled by the regional NEE compression stress field of the Altyn Tagh Fault at its south.

Key words: Kumukol anticline, lateral propagation, late Pleistocene, uplift rate

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