Episodic Orogeny Deduced from Coeval Sedimentary Sequences in the Foreland Basin and Its Implication for Uplift Process of Longmen Mountain, China

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > Journal of Mountain Science > Journal of Mountain Science-2013 > Vol10 No.1

	Episodic Orogeny Deduced from Coeval Sedimentary Sequences in the Foreland Basin and Its Implication for Uplift Process of Longmen Mountain, China
	LI Yong ; SU De-chen ; ZHOU Rong-jun ; LI Hai-bing ; Alexander L. DENSMORE ; YAN Liang ; YAN Zhao-kun
刊名	Journal of Mountain Science
	2013-02
卷号	10 期号:1 页码:29-42
关键词	Wedge-shaped megasequence Tabular megasequence Orogenic loading Erosional unloading Uplift process Longmen Mountain Foreland basin
通讯作者	LI Yong
英文摘要	Longmen Mountain located at the boundary between the Sichuan Basin and Tibetan Plateau, representing the steepest gradient of any edges of the plateau. Three endmember models of uplift process and mechanism have been proposed, including crustal thickening, crustal flow, and crustal isostatic rebound. Here we use coeval sedimentary sequences in the foreland basin to restraint uplift process and mechanism in the Longmen Mountain. The more than 10,000 m thick Late Triassic-Quaternary strata filled in this foreland basin and can be divided into six megasequences that are distinguished as two distinct types. The first type is the wedge-shaped megasequences which are sedimentary response of strong active thrust loading events, characterized by a high rate of subsidence and sediment accumulation, coarsening-upward succession and a dual-sourced sediment supply. This type includes Late Triassic, Late Jurassic to Early Cretaceous and Late Cretaceous to Paleogene megasequences. The second type is the tabular megasequences, characterized by the low rate of subsidence and sediment accumulation, fining-upward succession, and a single-sourced sediment supply, which is sedimentary response of isostatic rebound and erosion unloading. This type includes the Early to Middle Jurassic, Middle Cretaceous and Neogene to Quaternary megasequences. Basing on sedimentary, active tectonic, geomorphic evidence, we infer that the direction has been reversed from SSW-directed sinistral strike-slip to NNE-directed dextral strike-slip during 40-3.6 Ma, and since 3.6 Ma, the Longmen Mountain thrust belt belong to times of isostatic rebound and erosional unloading with NNE-directed dextral strike-slip. This suggests that crustal isostatic rebound is a primary driver for uplift and topography of the present Longmen Mountain. The Wenchuan (Ms8.0) earthquake, which ruptured a large thrust fault with NNE-directed dextral strike-slip along the range front, is an active manifestation of this crustal isostatic rebound process with dextral strike-slipping and shortening. This process may be the cause for the Wenchuan Earthquake and the apparent paradox of high relief, little shortening, the relative dearth of historical seismicity in the region.
收录类别	SCI
语种	英语
公开日期	2013-04-19
内容类型	期刊论文
源URL	[http://192.168.143.20:8080/handle/131551/5167]
专题	成都山地灾害与环境研究所_Journal of Mountain Science _Journal of Mountain Science-2013_Vol10 No.1
推荐引用方式 GB/T 7714	LI Yong,SU De-chen,ZHOU Rong-jun,et al. Episodic Orogeny Deduced from Coeval Sedimentary Sequences in the Foreland Basin and Its Implication for Uplift Process of Longmen Mountain, China[J]. Journal of Mountain Science,2013,10(1):29-42.
APA	LI Yong.,SU De-chen.,ZHOU Rong-jun.,LI Hai-bing.,Alexander L. DENSMORE.,...&YAN Zhao-kun.(2013).Episodic Orogeny Deduced from Coeval Sedimentary Sequences in the Foreland Basin and Its Implication for Uplift Process of Longmen Mountain, China.Journal of Mountain Science,10(1),29-42.
MLA	LI Yong,et al."Episodic Orogeny Deduced from Coeval Sedimentary Sequences in the Foreland Basin and Its Implication for Uplift Process of Longmen Mountain, China".Journal of Mountain Science 10.1(2013):29-42.