Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Hu, Wan-Long1,2; Wang, Qiang1,2,3,5 ; Yang, Jin-Hui4; Hao, Lu-Lu1,2; Wei, Gangjian1,2; Qi, Yue1; Wang, Jun1; Yang, Zong-Yong1; Sun, Peng1
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| Reworking and maturation of continental crust in collision zones: Insights from Early Cretaceous compositionally diverse magmatic rocks in central Tibet | |
| Source Publication | LITHOS
 |
| ISSN | 0024-4937 |
| 2024-05-01 | |
| Volume | 472Pages:15 |
| DOI | 10.1016/j.lithos.2024.107562 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics ; Mineralogy |
| Abstract | 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. |
| Keyword | Intrusive complex Crustal reworking Crustal maturation Continental collision zone Central Tibet |
| WOS ID | WOS:001218035700001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/76998 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Wang, Qiang |
| Affiliation | 1.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China 2.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 3.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 5.Chinese Acad Sci, Guangzhou Inst Geochem GIG, State Key Lab Isotope Geochem SKLaBIG, Wushan St, Guangzhou 510640, Peoples R China |
| Recommended Citation 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]. LITHOS,2024,472:15. |
| 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,472,15. |
| 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):15. |
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