气候变化领域集成服务门户(CCPortal): Crustal Anatexis and Initiation of the Continental-Scale Chongshan Strike-Slip Shear Zone on the Southeastern Tibetan Plateau

CCPortal

DOI	10.1029/2023TC007864
	Crustal Anatexis and Initiation of the Continental-Scale Chongshan Strike-Slip Shear Zone on the Southeastern Tibetan Plateau
	Li, Wenyuan; Cao, Shuyun; Dong, Yanlong; Zhan, Lefan; Tao, Lirong
发表日期	2023
ISSN	0278-7407
EISSN	1944-9194
卷号	42 期号:4
英文摘要	Continental-scale strike-slip shear zones often record significant tectono-magmatism and dynamic deformation processes of the crustal lithosphere. However, the genetic relationships and timing among the anatexis, deformation, and initial shearing along a strike-slip shear zone have not been well defined. Here, we carried out detailed field, microstructural, zircon U-Pb geochronology, geochemical and EBSD texture analyses of leucogranites and migmatites in the Chongshan shear zone (CS-SZ). The results indicate that most migmatites and leucogranites exhibit strong shear deformation and well-developed high-temperature mylonitic microstructures. The quartz aggregated from foliated leucogranites developed dominant high-temperature prism and prism slip systems. The pre- and syn-kinematic crustal anatexis and localized weak zone mainly occurred from 35 to 29 Ma along the CS-SZ, which is closely related to the post-collisional extension and collapse of overthickened crust. Biotite dehydration melting formed pre- and syn-kinematic melts and leucogranites that further experienced fractional crystallization of plagioclase and K-feldspar during melting and subsequent melt migration and emplacement upward along the tectonic weak zone. The thinning and weakening of lithospheric crust further facilitated the initial and formation strike-slip displacement along the CS-SZ, which occurred from 29 to 20 Ma or much later to 18 Ma. Finally, we propose that crustal anatexis and upward migrating melts play a key role in controlling the thermal state and rheological strength of the crust, resulting in nucleation and initiation of the localized deep-seated shear zone that accommodates significant displacement for the India-Asia continental forward collision and intracontinental deformation.
关键词	crustal anatexis leucogranites shear zone initiation rheological weakening
英文关键词	SHAN-RED-RIVER; LEFT-LATERAL SHEAR; BENEATH SE TIBET; AILAO-SHAN; DIANCANG SHAN; WESTERN YUNNAN; TECTONIC EVOLUTION; GEOCHRONOLOGICAL CONSTRAINTS; EXPERIMENTAL DEFORMATION; HIMALAYAN LEUKOGRANITE
WOS研究方向	Geochemistry & Geophysics
WOS记录号	WOS:000973066100001
来源期刊	TECTONICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283897
作者单位	China University of Geosciences - Wuhan
推荐引用方式 GB/T 7714	Li, Wenyuan,Cao, Shuyun,Dong, Yanlong,et al. Crustal Anatexis and Initiation of the Continental-Scale Chongshan Strike-Slip Shear Zone on the Southeastern Tibetan Plateau[J],2023,42(4).
APA	Li, Wenyuan,Cao, Shuyun,Dong, Yanlong,Zhan, Lefan,&Tao, Lirong.(2023).Crustal Anatexis and Initiation of the Continental-Scale Chongshan Strike-Slip Shear Zone on the Southeastern Tibetan Plateau.TECTONICS,42(4).
MLA	Li, Wenyuan,et al."Crustal Anatexis and Initiation of the Continental-Scale Chongshan Strike-Slip Shear Zone on the Southeastern Tibetan Plateau".TECTONICS 42.4(2023).