Syn-collisional extension and Ni-Cu sulfide-bearing mafic magma emplacement along the Irtysh Shear Zone in the Central Asian Orogenic Belt
文献类型：期刊论文
| 作者 | Wei, Bo2,3,4; Wang, Christina Yan2,3,4; Li, Pengfei1,3
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| 刊名 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
 |
| 出版日期 | 2024 |
| 卷号 | 136期号:1-2页码:403-417 |
| ISSN号 | 0016-7606 |
| DOI | 10.1130/B36759.1 |
| 英文摘要 | The Central Asian Orogenic Belt was characterized by a long-lived accretionary history from Neoproterozoic to Paleozoic, followed by a collisional phase of orogeny in the latest Paleozoic with the closure of the Paleo-Asian tion associated with mantle-derived mafic magmas in the Central Asian Orogenic Belt was relatively short-lived. Thus, the coherence between the protracted accretionary and collisional history of the Central Asian Orogenic Belt and the transient Ni-Cu sulfide-bearing mafic magmatism is difficult to understand. We investigated both Ni-Cu sulfidebearing and sulfide-barren mafic intrusions along a major suture zone of the Irtysh Shear Zone within the Central Asian Orogenic Belt to understand the origin of shortlived Ni-Cu sulfide mineralization in the context of the collision of two arc systems of the Chinese Altai and the East Junggar regions. Zircon U-Pb dating results for the Ni-Cu sulfide-bearing mafic intrusions show that they were only emplaced briefly from 290 Ma to 280 Ma after subduction terminated (ca. 312 Ma), substantially earlier than Ni-Cu sulfide-barren mafic intrusions (ca. 274-271 Ma). Zircons from all Ni-Cu sulfide-bearing/barren mafic intrusions from 6.0 to 7.4%0, higher than the typical mantle value ( 5.3%0), which indicates their derivation from a metasomatized mantle with inherited subduction signatures. The 611B values of the rocks from these intrusions range from -17.2%0 to -2.3%0, significantly lower than those of typical volcanic arcs (up to +18%0), which suggests that the metaso- matic components in the mantle source were dominated by sediment melts rather than fluids. The pressure calculated using amphi- bole thermobarometry shows that the pa- rental magmas of the Ni-Cu sulfide -bearing mafic intrusions were emplaced shallower than those of Ni-Cu sulfide -barren mafic intrusions. This is supported by the fact that the country rocks of the Ni-Cu sulfide - bearing mafic intrusions are shallow crustal lithologies of sedimentary rocks, whereas the country rocks of the barren intrusions are relatively deeper crustal lithologies of high-grade metamorphic rocks and gran- ites. Olivine from the Ni-Cu sulfide -barren intrusions has forsterite (Fo) contents rang- ing from 51.1 mol% to 76.2 mol% and Ni from 196 ppm to 1312 ppm. These values are much lower than those of the Ni-Cu sulfide -bearing intrusions (Fo = 72.6- 79.4 mol%; Ni = 1022-1925 ppm), which indicates that the parental magmas of the barren intrusions may have experienced ex- tensive olivine crystallization. Notably, the emplacement of the Ni-Cu sulfide -bearing mafic intrusions (290-280 Ma) coincidently overlapped with a transient period of oro- gen -parallel extension (ca. 295-280 Ma) in response to the collision of the Chinese Altai and East Junggar. Syn-collisional extension may lead to the rapid ascent and emplace- ment of mantle -derived mafic magmas at a shallower crustal level, preventing signifi- cant loss of Ni from olivine crystallization at depths, and thus providing metal -rich mafic magmas for potential Ni-Cu sulfide miner- alization. Our results highlight that syn-col- lisional extension is an essential geodynamic mechanism that controls the emplacement of Ni-Cu sulfide -bearing mafic intrusions in orogenic belts. |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:001171011000003 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/77254]  |
| 专题 | 中国科学院矿物学与成矿学重点实验室 |
| 通讯作者 | Wang, Christina Yan |
| 作者单位 | 1.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China 2.Guangdong Prov Key Lab Mineral Phys & Mat, Guangzhou 510640, Peoples R China 3.Chinese Acad Sci, Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 4.Chinese Acad Sci, Key Lab Mineral & Metallogeny, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wei, Bo,Wang, Christina Yan,Li, Pengfei. Syn-collisional extension and Ni-Cu sulfide-bearing mafic magma emplacement along the Irtysh Shear Zone in the Central Asian Orogenic Belt[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2024,136(1-2):403-417. |
| APA | Wei, Bo,Wang, Christina Yan,&Li, Pengfei.(2024).Syn-collisional extension and Ni-Cu sulfide-bearing mafic magma emplacement along the Irtysh Shear Zone in the Central Asian Orogenic Belt.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,136(1-2),403-417. |
| MLA | Wei, Bo,et al."Syn-collisional extension and Ni-Cu sulfide-bearing mafic magma emplacement along the Irtysh Shear Zone in the Central Asian Orogenic Belt".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 136.1-2(2024):403-417. |
入库方式： OAI收割
来源：广州地球化学研究所
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