气候变化领域集成服务门户(CCPortal): Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems

CCPortal

DOI	10.1130/B25778.1
	Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems
	Wang, E; Xu, FY; Zhou, JX; Wan, JL; Burchfiel, BC
发表日期	2006
ISSN	0016-7606
EISSN	1943-2674
起始页码	349
结束页码	365
卷号	118 期号:3-4
英文摘要	The Qaidam basin is the largest Cenozoic intermontane basin within the Tibetan plateau, bounded by the Qilian Shan range to the north, the East Kunlun range to the south, the Altyn Tagh range to the west, and the Ela Shan range to the east. Its deposits consist of nonmarine sedimentary rocks, with a maximum thickness exceeding 43,400 in. Modern sedimentation mainly takes place along the marginal areas of the basin, where alluvial fans are formed along a series of rivers that originate from the surrounding mountains. Nevertheless, drilling, sedimentary, and seismic data reveal that the depocenter of the basin during much of Cenozoic time was not developed as foreland basins of the Qilian Shan belt to the north and the East Kunlun belt to the south, but instead the depocenter was in the center of the western part of the basin and had a northwest-southeast trend that shifted eastward similar to 380 km during Oligocene to Quaternary time. This indicates that most of the basin sediments were not derived from the surrounding mountain ranges. The results of the fission-track age dating reveal that the rapid uplift of the Yousha Shan anticline bounding the depocenter to the southwest initiated at ca. 31 Ma, indicating that the southeastward shift of the depocenter began at that time, yielding a migration rate for the depocenter of 10.2 min/yr. The northwestern margin of the depocenter of the Qaidam basin lies to the east of the westward prolongation of the Qaidam basin, the Tula trough, a 300-km-long narrow trough flanked by the Altyn Tagh range along the Altyn Tagh strike-slip fault on the north and the East Kunlun thrust belt on the south. The sedimentary and deformational evidence from this region indicates that the Tula trough was formed as a syncline, along which a paleoriver flowed to the east into the Qaidam basin. To the southwest, this river valley merges with the trace of the Altyn Tagh fault. The latter and its westward continuation are interpreted to have extended to the northern margin or the Pamir folded belt north of the western syntaxis of the Himalaya. We propose that most of the sediments within the depocenter of the Qaidam basin were transported from the northern margin of the Pamir folded belt along a progressively lengthening 2000-km-long longitudinal river that developed along the left-lateral Altyn Tagh fault and its western continuation, as the eastward extrusion of the Tibetan plateau took place in Oligocene time. Both the crustal uplift and continuous southeastward aggradations of the sediments carried by the paleo-Kunlun River are interpreted to be the cause for southeastward migration of the depocenter of the Qaidam basin. The longitudinal river disappeared in late Cenozoic time (2-4 Ma) due to stream capture and climate change.
关键词	INDIA-ASIA COLLISION TIBETAN PLATEAU TECTONIC EVOLUTION KINEMATIC MODEL KARAKORAM FAULT NORTHERN TIBET CLIMATE-CHANGE CHINA DEFORMATION SHAN
英文关键词	Tibetan plateau; Qaidam basin; depocenter eastward migration; longitudinal river
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000235962700007
来源期刊	GEOLOGICAL SOCIETY OF AMERICA BULLETIN
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257449
推荐引用方式 GB/T 7714	Wang, E,Xu, FY,Zhou, JX,et al. Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems[J]. 中国科学院青藏高原研究所,2006,118(3-4).
APA	Wang, E,Xu, FY,Zhou, JX,Wan, JL,&Burchfiel, BC.(2006).Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,118(3-4).
MLA	Wang, E,et al."Eastward migration of the Qaidam basin and its implications for Cenozoic evolution of the Altyn Tagh fault and associated river systems".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 118.3-4(2006).