气候变化领域集成服务门户(CCPortal): Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet

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DOI	10.1016/j.lithos.2024.107562
	Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet
	Hu, Wan-Long; Wang, Qiang; Yang, Jin-Hui; Hao, Lu-Lu; Wei, Gangjian; Qi, Yue; Wang, Jun; Yang, Zong-Yong; Sun, Peng
发表日期	2024
ISSN	0024-4937
EISSN	1872-6143
起始页码	472
卷号	472
英文摘要	The reworking of continental crust in collision zones is a key process in the chemical maturation of crustal rocks. However, the mechanisms that cause crustal reworking remain highly controversial. The compositionally diverse magmatic rocks along the Lhasa - Qiangtang collision zone provide a favorable opportunity for studying the mechanism of crustal reworking and maturation in continental collision zones. Here we report zircon U - Pb ages and Hf isotopes, mineral major elements, and whole-rock geochemistry and Sr - Nd isotopes for the Momu intrusive complex in the Lhasa - Qiangtang collision zone, central Tibet. Zircon U - Pb ages reveal that the intrusive complex formed during the late Early Cretaceous (115 - 113 Ma). Diorites from the intrusive complex have high Mg # values (49.7 - 51.2) and initial 87 Sr/ 86 Sr ratios (0.7082 to 0.7083), and low e Nd (t) values ( - 7.3 to - 6.9), with negative to slight positive zircon e Hf (t) values ( - 3.8 to + 0.8), suggesting that these rocks were likely generated by the partial melting of the enriched lithospheric mantle. Granodiorites from the intrusive complex have high SiO 2 (64.4 - 67.9 wt%) and Al 2 O 3 (14.8 - 16.1 wt%) and low MgO (1.4 - 1.8 wt%) contents. These rocks are also characterized by high initial 87 Sr/ 86 Sr ratios (0.7091 - 0.7098) and whole-rock negative e Nd (t) ( - 9.9 to - 8.4) and zircon e Hf (t) ( - 7.9 to - 2.2) values. The associated granites have the highest SiO 2 (68.7 - 71.5 wt%) contents among the intrusive complex rocks, high initial 87 Sr/ 86 Sr (0.7089 - 0.7093) ratios, and negative wholerock e Nd (t) ( - 10.1 to - 7.7) and zircon e Hf (t) ( - 5.3 to - 0.2) values. These geochemical characteristics indicate that the granodiorites were most likely derived from the partial melting of ancient continental crust and that the coeval granites were formed by the fractional crystallization of granodioritic magmas. Integrating our new results with data for the coeval magmatic rocks of the Lhasa - Qiangtang collision zone, we suggest that the Momu intrusive complex formed in a post-collisional slab breakoff setting. Asthenosphere upwelling caused by slab breakoff could have provided a substantial source of heat for crustal reworking, which gradually contributed to the maturation of continental crust in the Lhasa - Qiangtang collision zone.
英文关键词	Intrusive complex; Crustal reworking; Crustal maturation; Continental collision zone; Central Tibet
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:001218035700001
来源期刊	LITHOS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/289585
作者单位	Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Institute of Geology & Geophysics, CAS; Chinese Academy of Sciences
推荐引用方式 GB/T 7714	Hu, Wan-Long,Wang, Qiang,Yang, Jin-Hui,et al. Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet[J],2024,472.
APA	Hu, Wan-Long.,Wang, Qiang.,Yang, Jin-Hui.,Hao, Lu-Lu.,Wei, Gangjian.,...&Sun, Peng.(2024).Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet.LITHOS,472.
MLA	Hu, Wan-Long,et al."Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet".LITHOS 472(2024).