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DOI	10.1130/G32069.1
	Peneplain formation in southern Tibet predates the India-Asia collision and plateau uplift
	Hetzel, Ralf; Dunkl, Istvan; Haider, Vicky; Strobl, Marcus; von Eynatten, Hilmar; Ding, Lin; Frei, Dirk
通讯作者	Hetzel, R (通讯作者)
发表日期	2011
ISSN	0091-7613
EISSN	1943-2682
起始页码	983
结束页码	986
卷号	39 期号:10
英文摘要	The uplift history of Tibet is crucial for understanding the geodynamic and paleoclimatologic evolution of Asia; however, it remains controversial whether Tibet attained its high elevation before or after India collided with Asia similar to 50 m.y. ago. Here we use thermochronologic and cosmogenic nuclide data from a large bedrock peneplain in southern Tibet to shed light on the timing of the uplift. The studied peneplain, which was carved into Cretaceous granitoids and Jurassic metasediments, is located in the northern Lhasa block at an altitude of similar to 5300 m. Thermal modeling based on (U-Th)/He ages of apatite and zircon, and apatite fission track data, indicate cooling and exhumation of the granitoids between ca. 70 and ca. 55 Ma, followed by a rapid decline in exhumation rate from similar to 300 m/m.y. to similar to 10 m/m.y. between ca. 55 and ca. 48 Ma. Since then, the peneplain has been a rather stable geomorphic feature, as indicated by low local and catchment-wide erosion rates of 6-11 m/m.y. and 11-16 m/m.y., respectively, which were derived from cosmogenic Be-10 concentrations in bedrock, grus, and stream sediment. The prolonged phase of erosion and planation that ended ca. 50 Ma removed 3-6 km of rock from the peneplain region, likely accomplished by laterally migrating rivers. The lack of equivalent sediments in the northern Lhasa block and the presence of a regional unconformity in the southern Lhasa block indicate that the rivers delivered this material to the ocean. This implies that erosion and peneplanation proceeded at low elevation until India's collision with Asia induced crustal thickening, surface uplift, and long-term preservation of the peneplain.
关键词	FORE-ARC BASIN TECTONIC EVOLUTION LHASA GEOLOGY EOCENE
语种	英语
WOS研究方向	Geology
WOS类目	Geology
WOS记录号	WOS:000294818700022
来源期刊	GEOLOGY
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/257938
推荐引用方式 GB/T 7714	Hetzel, Ralf,Dunkl, Istvan,Haider, Vicky,et al. Peneplain formation in southern Tibet predates the India-Asia collision and plateau uplift[J]. 中国科学院青藏高原研究所,2011,39(10).
APA	Hetzel, Ralf.,Dunkl, Istvan.,Haider, Vicky.,Strobl, Marcus.,von Eynatten, Hilmar.,...&Frei, Dirk.(2011).Peneplain formation in southern Tibet predates the India-Asia collision and plateau uplift.GEOLOGY,39(10).
MLA	Hetzel, Ralf,et al."Peneplain formation in southern Tibet predates the India-Asia collision and plateau uplift".GEOLOGY 39.10(2011).