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DOI	10.1130/B25595.1
	Cretaceous-Tertiary shortening, basin development, and volcanism in central Tibet
	Kapp, P; Yin, A; Harrison, TM; Ding, L
发表日期	2005
ISSN	0016-7606
EISSN	1943-2674
起始页码	865
结束页码	878
卷号	117 期号:7-8
英文摘要	The geologic map pattern of the Qiangtang terrane in central Tibet defines a > 600-km-long and up to 270-km-wide east-plunging structural culmination. It is characterized by early Mesozoic blueschist-bearing melange and upper Paleozoic strata in the core and mainly Triassic-Jurassic strata along the limbs. In the western Qiangtang terrane (similar to 84(circle)E), the culmination is unconformably overlain by weakly deformed mid-Cretaceous volcanic flows and tuffs. Along the Bangong suture to the south (32(circle)N, 84(circle)E), mid-Cretaceous nonmarine red beds and volcanic rocks lie unconformably on Jurassic suture zone rocks. These relationships demonstrate that west-central Tibet was above sea level during the mid-Cretaceous and experienced significant denudation prior to mid-Cretaceous time. Growth of the Qiangtang culmination is inferred to have initiated during southward emplacement of a thrust sheet of early Mesozoic melange and upper Paleozoic strata during the Early Cretaceous Lhasa-Qiangtang collision. The north-south width of the inferred thrust sheet provides a minimum slip estimate of similar to 150 km at 84(circle)E, decreasing eastward to similar to 70 km at 87(circle)E. Paleogene deformation in the Qiangtang terrane is characterized by widely distributed, mainly north-dipping thrust faults that cut Eocene-Oligocene red beds and volcanic rocks in their footwall. Along the Bangong suture, the north-dipping Shiquanhe-Gaize-Amdo thrust system cuts 64 and 43 m.y. old volcanic tuffs in its footwall and accommodated > 40km of post-mid-Cretaceous shortening. The Tertiary south-dipping Gaize-Siling Co backthrust bounds the southern margin of the Bangong suture and marks the northernmost limit of mid-Cretaceous marine strata in central Tibet. Cretaceous deformation and denudation in central Tibet is attributed to northward underthrusting of the Lhasa terrane beneath the Qiangtang terrane along the Bangong suture. This model implies that (1) Cretaceous strata along the Bangong suture and in the northern Lhasa terrane were deposited in a flexural foreland basin system and derived at least in part from the Qiangtang terrane, and (2) the central Tibetan crust was thickened substantially prior to the Indo-Asian collision. Although its magnitude is poorly known, Tertiary shortening in the Qiangtang terrane is more prevalent than in the Lhasa terrane; this difference may be attributed to the presence of underthrust melange in the deeper central Tibetan crust, which would have made it weaker than the Lhasa terrane during the Indo-Asian collision.
关键词	INDO-ASIAN COLLISION EAST-WEST EXTENSION NUJIANG SUTURE ZONE HOH XIL BASIN TECTONIC EVOLUTION LHASA BLOCK SOUTHERN TIBET PLATEAU DEFORMATION ROCKS
英文关键词	Tibet; plateau formation; continental collision; underthrusting; suture; shortening
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000229991100003
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/257389
推荐引用方式 GB/T 7714	Kapp, P,Yin, A,Harrison, TM,et al. Cretaceous-Tertiary shortening, basin development, and volcanism in central Tibet[J]. 中国科学院青藏高原研究所,2005,117(7-8).
APA	Kapp, P,Yin, A,Harrison, TM,&Ding, L.(2005).Cretaceous-Tertiary shortening, basin development, and volcanism in central Tibet.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,117(7-8).
MLA	Kapp, P,et al."Cretaceous-Tertiary shortening, basin development, and volcanism in central Tibet".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 117.7-8(2005).