气候变化领域集成服务门户(CCPortal): Paleomagnetic constraints on the paleolatitude of the Lhasa block during the Early Cretaceous: Implications for the onset of India-Asia collision and latitudinal shortening estimates across Tibet and stable Asia

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DOI	10.1016/j.gr.2015.05.013
	Paleomagnetic constraints on the paleolatitude of the Lhasa block during the Early Cretaceous: Implications for the onset of India-Asia collision and latitudinal shortening estimates across Tibet and stable Asia
	Li, Zhenyu; Ding, Lin; Song, Peiping; Fu, Jiajun; Yue, Yahui
通讯作者	Li, ZY (通讯作者)
发表日期	2017
ISSN	1342-937X
EISSN	1878-0571
起始页码	352
结束页码	372
卷号	41
英文摘要	Interbedded volcano-sedimentary sequences are well exposed in the northern part of the Lhasa block in southern Tibet. Zircon U-Pb dating results from two samples indicate that the emplacement age of the Duoni Formation volcanic flows is 120.2 +/- 0.5 Ma. Paleomagnetic results from 235 progressively demagnetized volcanic rock samples (25 sites) and 41 sandstone samples (5 sites) indicate that the dominant remanence carriers are Ti-poor titanomagnetite and Ti-poor titanohematite in the volcanic samples and Ti-rich titanomagnetite in the sandstone samples. Rock magnetic investigations, systematic demagnetization behavior, positive fold test results, and direct petrographic identifications all indicate that the paleodirections recorded by the chemically stable magnetic particles are primary thermal remanent magnetization in the volcanic flows and primary detrital remanent magnetization in the sandstones. The tilt-corrected ChRM mean direction is D/I = 356.4 degrees/16.4 degrees with alpha(95) = 6.3 degrees (N = 19), corresponding to a paleopole position of lambda(p) = 66.9 degrees N, phi(p) = 281.2 degrees E with A(95) = 6.1 degrees. Combined with previously published results, the geochronological dating and paleomagnetic analysis indicate a paleolatitude of 13.1 +/- 2.7 degrees N for the southern margin of the Lhasa block during the Early Cretaceous. Therefore, the southernmost margin of the Eurasian continent likely remained at the low-middle paleolatitude of 13.1 +/- 2.7 degrees N between the Early Cretaceous and the Paleocene. Based on comparisons to results from the Tethyan-Himalayan block and the reference poles from stable India and Eurasia, the low-middle paleoposition of the Lhasa block during the Early Cretaceous through Early Paleocene suggests that the initial contact between India and Asia occurred at ca. 59.3 Ma. Under the assumption of a rigid Eurasian plate, this timing implies that a total collision-related latitudinal convergence of 1450 +/- 400 km (13.1 +/- 3.7 degrees N) has been accommodated by folding, thrust faulting, normal faulting, crustal thickening, intracontinental subduction in Tibet and central Asia and southeastward continental extrusion of the Indo-China block from the eastern syntaxis between the Lhasa block and stable Asia. (C) 2015 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
关键词	ZIRCON U-PB FORELAND BASIN EVOLUTION SOUTHERN TIBET TECTONIC EVOLUTION VOLCANIC-ROCKS STRUCTURAL EVOLUTION SILICICLASTIC ROCKS CENOZOIC TECTONICS PLATE-TECTONICS MAGNETIC-FIELD
英文关键词	Lhasa block; Early Cretaceous; Paleolatitude; India-Asia collision; Crustal shortening
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000397873300023
来源期刊	GONDWANA RESEARCH
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/258879
推荐引用方式 GB/T 7714	Li, Zhenyu,Ding, Lin,Song, Peiping,et al. Paleomagnetic constraints on the paleolatitude of the Lhasa block during the Early Cretaceous: Implications for the onset of India-Asia collision and latitudinal shortening estimates across Tibet and stable Asia[J]. 中国科学院青藏高原研究所,2017,41.
APA	Li, Zhenyu,Ding, Lin,Song, Peiping,Fu, Jiajun,&Yue, Yahui.(2017).Paleomagnetic constraints on the paleolatitude of the Lhasa block during the Early Cretaceous: Implications for the onset of India-Asia collision and latitudinal shortening estimates across Tibet and stable Asia.GONDWANA RESEARCH,41.
MLA	Li, Zhenyu,et al."Paleomagnetic constraints on the paleolatitude of the Lhasa block during the Early Cretaceous: Implications for the onset of India-Asia collision and latitudinal shortening estimates across Tibet and stable Asia".GONDWANA RESEARCH 41(2017).