Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Ma, Xin1,2; Dan, Wei1,3 ; Wang, Jian1,2; Wang, Qiang1,2,3; Tang, Guo-Rong1,2; Gadoev, Mustafo4; Oimahmadov, Ilhomjon4; Tang, Gong-Jian1,3
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| Cretaceous magmatic migration and flare-up in Pamir-Karakoram | |
| Source Publication | LITHOS
 |
| ISSN | 0024-4937 |
| 2023-10-01 | |
| Volume | 454Pages:11 |
| DOI | 10.1016/j.lithos.2023.107285 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics ; Mineralogy |
| Abstract | The Pamir-Karakoram terrain contains abundant Cretaceous granitoids, and minor coeval volcanic rocks and mafic intrusions, which represent a wide (ca. 400 km) continental arc developed during northward subduction of Neo-Tethys oceanic lithosphere. However, little is known of the tectonic controls on the magmatic flare-ups and their implications for crustal thickening. In this paper, we report new zircon U-Pb age and Hf isotope data for Cretaceous biotite granites, two-mica granites and mafic microgranular enclaves (MMEs) from the large-scale granitic batholiths in Pamir. These and previously published results show there were four episodes of Cretaceous magmatism (124-108, 107-103, 102-92, and 80-70 Ma). The Cretaceous arc migrated progressively landward from Karakoram to Central Pamir with a maximum arc-trench distance of ca. 400 km during the first magmatic episode (124-108 Ma). The igneous rocks are mainly S-type granites with enriched zircon Hf isotopic compositions (& epsilon;Hf(t) = -19.8 to -5.4), indicating derivation by partial melting of metasedimentary units. A magmatic flare-up at 105 & PLUSMN; 2 Ma generated voluminous I-type granites and minor mafic igneous rocks that cover ca. 30% of the study area. The I-type granites have higher zircon & epsilon;Hf(t) values (-19.0 to -2.0) as compared with those of the earlier S-type granites, which reflect the addition of mantle-derived materials (ca. 30%). The third episode of magmatism (102-92 Ma) generated mainly intermediate-silicic volcanic rocks, which are geochemically similar to I-type granites and have & epsilon;Hf(t) values of -15.0 to -1.5. The final episode of magmatism (80-70 Ma) was dominated by alkaline and mafic igneous rocks formed in a post-collisional setting, which have variable & epsilon;Hf(t) values of -6.6 to 10.5. Our study highlights that the Early Cretaceous magmatic flare-up in the Pamir-Karakoram terrain was related to foundering of the flat-slab of Neo-Tethys oceanic lithosphere that was previously subducted, which induced voluminous underplating of mantle-derived magma in the lower crust. This process had a key role in crustal thickening in the Pamir-Karakoram terrain prior to the Cenozoic India-Asia collision. |
| Keyword | Magmatic flare-up Arc migration Neo-Tethys Ocean Crustal thickening Pamir-Karakoram |
| WOS ID | WOS:001046776600001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/74635 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Tang, Gong-Jian |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 3.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 4.Tajik Acad Sci, Inst Geol Earthquake Engn & Seismol, Dushanbe, Tajikistan |
| Recommended Citation GB/T 7714 | Ma, Xin,Dan, Wei,Wang, Jian,et al. Cretaceous magmatic migration and flare-up in Pamir-Karakoram[J]. LITHOS,2023,454:11. |
| APA | Ma, Xin.,Dan, Wei.,Wang, Jian.,Wang, Qiang.,Tang, Guo-Rong.,...&Tang, Gong-Jian.(2023).Cretaceous magmatic migration and flare-up in Pamir-Karakoram.LITHOS,454,11. |
| MLA | Ma, Xin,et al."Cretaceous magmatic migration and flare-up in Pamir-Karakoram".LITHOS 454(2023):11. |
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