气候变化领域集成服务门户(CCPortal): Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet

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DOI	10.3390/geosciences11050209
	Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet
	Burke, William B.; Laskowski, Andrew K.; Orme, Devon A.; Sundell, Kurt E.; Taylor, Michael H.; Guo, Xudong; Ding, Lin
通讯作者	Burke, WB (通讯作者)
发表日期	2021
EISSN	2076-3263
卷号	11 期号:5
英文摘要	North-trending rifts throughout south-central Tibet provide an opportunity to study the dynamics of synconvergent extension in contractional orogenic belts. In this study, we present new data from the Dajiamang Tso rift, including quantitative crustal thickness estimates calculated from trace/rare earth element zircon data, U-Pb geochronology, and zircon-He thermochronology. These data constrain the timing and rates of exhumation in the Dajiamang Tso rift and provide a basis for evaluating dynamic models of synconvergent extension. Our results also provide a semi-continuous record of Mid-Cretaceous to Miocene evolution of the Himalayan-Tibetan orogenic belt along the India-Asia suture zone. We report igneous zircon U-Pb ages of similar to 103 Ma and 70-42 Ma for samples collected from the Xigaze forearc basin and Gangdese Batholith/Linzizong Formation, respectively. Zircon-He cooling ages of forearc rocks in the hanging wall of the Great Counter thrust are similar to 28 Ma, while Gangdese arc samples in the footwalls of the Dajiamang Tso rift are 16-8 Ma. These data reveal the approximate timing of the switch from contraction to extension along the India-Asia suture zone (minimum 16 Ma). Crustal-thickness trends from zircon geochemistry reveal possible crustal thinning (to similar to 40 km) immediately prior to India-Eurasia collision onset (58 Ma). Following initial collision, crustal thickness increases to 50 km by 40 Ma with continued thickening until the early Miocene supported by regional data from the Tibetan Magmatism Database. Current crustal thickness estimates based on geophysical observations show no evidence for crustal thinning following the onset of E-W extension (similar to 16 Ma), suggesting that modern crustal thickness is likely facilitated by an underthrusting Indian lithosphere balanced by upper plate extension.
关键词	XIGAZE FORE-ARC ASIA SUTURE ZONE EAST-WEST EXTENSION U-PB GEOCHRONOLOGY STRUCTURAL EVOLUTION FACIES ARCHITECTURE TECTONIC EVOLUTION SOUTHWESTERN TIBET DULUTH COMPLEX LAZI REGION
英文关键词	Tibet; E-W extension; crustal thickness; T/REE geochemistry; geochronology; thermochronology
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000654006500001
来源期刊	GEOSCIENCES
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/260395
推荐引用方式 GB/T 7714	Burke, William B.,Laskowski, Andrew K.,Orme, Devon A.,et al. Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet[J]. 中国科学院青藏高原研究所,2021,11(5).
APA	Burke, William B..,Laskowski, Andrew K..,Orme, Devon A..,Sundell, Kurt E..,Taylor, Michael H..,...&Ding, Lin.(2021).Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet.GEOSCIENCES,11(5).
MLA	Burke, William B.,et al."Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet".GEOSCIENCES 11.5(2021).