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DOI	10.1016/j.jseaes.2013.03.005
	Cretaceous to Cenozoic evolution of the northern Lhasa Terrane and the Early Paleogene development of peneplains at Nam Co, Tibetan Plateau
	Haider, Vicky L.; Dunkl, Istvan; von Eynatten, Hilmar; Ding, Lin; Frei, Dirk; Zhang, Liyun
通讯作者	Haider, VL (通讯作者)
发表日期	2013
ISSN	1367-9120
EISSN	1878-5786
起始页码	79
结束页码	98
卷号	70-71
英文摘要	Highly elevated and well-preserved peneplains are characteristic geomorphic features of the Tibetan plateau in the northern Lhasa Terrane, north-northwest of Nam Co. The peneplains were carved in granitoids and in their metasedimentary host formations. We use multi-method geochronology (zircon U-Pb and [U-Th]/He dating and apatite fission track and [U-Th]/He dating) to constrain the post-emplacement thermal history of the granitoids and the timing and rate of final exhumation of the peneplain areas. LA-ICP-MS U-Pb geochronology of zircons yields two narrow age groups for the intrusions at around 118 Ma and 85 Ma, and a third group records Paleocene volcanic activity (63-58 Ma) in the Nam Co area. The low-temperature thermochronometers indicate common age groups for the entire Nam Co area: zircon (U-Th)/He ages cluster around 75 Ma, apatite fission track ages around 60 Ma and apatite (U-Th)/He ages around 50 Ma. Modelling of the thermochronological data indicates that exhumation of the basement blocks took place in latest Cretaceous to earliest Paleogene time. By Middle Eocene time the relief was already flat, documented by a thin alluvial sediment sequence covering a part of the planated area. The present-day horst and graben structure of the peneplains is a Late Cenozoic feature triggered by E-W extension of the Tibetan Plateau. The new thermochronological data precisely bracket the age of the planation to Early Eocene, i.e. between ca. 55 and 45 Ma. The erosional base level can be deduced from the presence of Early Cretaceous zircon grains in Eocene strata of Bengal Basin. The sediment generated during exhumation of the Nam Co area was transported by an Early Cenozoic river system into the ocean, suggesting that planation occurred at low elevation. (C) 2013 Elsevier Ltd. All rights reserved.
关键词	TRACK ANNEALING KINETICS INDIA-ASIA COLLISION EAST-WEST EXTENSION EARLY UPLIFT HISTORY TSANGPO SUTURE ZONE SOUTHERN TIBET U-PB TECTONIC EVOLUTION HELIUM DIFFUSION BASIN EVOLUTION
英文关键词	Thermochronology; U-Pb; Geomorphology; Peneplain; Tibetan Plateau
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000320076600007
来源期刊	JOURNAL OF ASIAN EARTH SCIENCES
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/258156
推荐引用方式 GB/T 7714	Haider, Vicky L.,Dunkl, Istvan,von Eynatten, Hilmar,et al. Cretaceous to Cenozoic evolution of the northern Lhasa Terrane and the Early Paleogene development of peneplains at Nam Co, Tibetan Plateau[J]. 中国科学院青藏高原研究所,2013,70-71.
APA	Haider, Vicky L.,Dunkl, Istvan,von Eynatten, Hilmar,Ding, Lin,Frei, Dirk,&Zhang, Liyun.(2013).Cretaceous to Cenozoic evolution of the northern Lhasa Terrane and the Early Paleogene development of peneplains at Nam Co, Tibetan Plateau.JOURNAL OF ASIAN EARTH SCIENCES,70-71.
MLA	Haider, Vicky L.,et al."Cretaceous to Cenozoic evolution of the northern Lhasa Terrane and the Early Paleogene development of peneplains at Nam Co, Tibetan Plateau".JOURNAL OF ASIAN EARTH SCIENCES 70-71(2013).