气候变化领域集成服务门户(CCPortal): Tectono-magmatic response to the geometric evolution of slab breakoff in the Paleo-Tethys Ocean: Constraints from Late Triassic granites in the Qiangtang block, northern Tibet

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DOI	10.1130/B36456.1
	Tectono-magmatic response to the geometric evolution of slab breakoff in the Paleo-Tethys Ocean: Constraints from Late Triassic granites in the Qiangtang block, northern Tibet
	Wu, Hao; Liu, Xi -Jun; Chen, Jing-Wen; Li, Cai; Yang, Rui; Jiang, Zi-Qi
发表日期	2024
ISSN	0016-7606
EISSN	1943-2674
起始页码	136
结束页码	1-2
卷号	136 期号:1-2
英文摘要	Slab breakoff can explain the postcollisional igneous and metamorphic events in many collisional orogens and triggers the transition from initial continental collision to deep subduction. However, the relationship between the deep-seated geometry of slab breakoff and shallow tectono-magmatic events remains unclear. In this study, we report new geochronological, geochemical, and Hf isotope data for granitic rocks from the Qiangtang block. Three granitic samples yielded zircon U-Pb ages of 226-214 Ma and mostly gave negative zircon epsilon Hf(t) values of -20.1 to +0.57. These granitoids are K -rich, calc-alkaline, magnesian, and metaluminous to weakly peraluminous. We propose that the granites were generated by partial melting of compositionally heterogeneous lower crust in the Southern Qiangtang block. Our new data, along with previously published data for igneous and metamorphic rocks in the Qiangtang block, suggest that the Longmu Co-Shuanghu suture zone represents a remnant of the closure of the Paleo-Tethys Ocean, and that the Late Triassic tectono-magmatic evolution was controlled by slab breakoff after continental collision. The contrasting magmatic and metamorphic ages show that the two stages of tectono-magmatic activity in the Late Triassic were due to a change in the subduction angle of the continental lithosphere from steep (225-215 Ma) to shallow (215-205 Ma) during slab breakoff. Furthermore, we infer that slab breakoff of the oceanic lithosphere caused extensive crustal melting and reworking and initiated far -field subduction. Our results provide new insights into the slab breakoff processes that control the geometry of subducting continental lithosphere and related postcollisional magmatic and metamorphic events in collision zones.
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:001171011000007
来源期刊	GEOLOGICAL SOCIETY OF AMERICA BULLETIN
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/301797
作者单位	Guilin University of Technology; Guilin University of Technology; Jilin University; China Geological Survey; Guilin University of Technology
推荐引用方式 GB/T 7714	Wu, Hao,Liu, Xi -Jun,Chen, Jing-Wen,et al. Tectono-magmatic response to the geometric evolution of slab breakoff in the Paleo-Tethys Ocean: Constraints from Late Triassic granites in the Qiangtang block, northern Tibet[J],2024,136(1-2).
APA	Wu, Hao,Liu, Xi -Jun,Chen, Jing-Wen,Li, Cai,Yang, Rui,&Jiang, Zi-Qi.(2024).Tectono-magmatic response to the geometric evolution of slab breakoff in the Paleo-Tethys Ocean: Constraints from Late Triassic granites in the Qiangtang block, northern Tibet.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,136(1-2).
MLA	Wu, Hao,et al."Tectono-magmatic response to the geometric evolution of slab breakoff in the Paleo-Tethys Ocean: Constraints from Late Triassic granites in the Qiangtang block, northern Tibet".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 136.1-2(2024).