Crustal Growth Identified by High-& delta;O-18 Zircon and Olivine: A Perspective from Ultramafic Arc Cumulates in Southern Tibet
文献类型：期刊论文
| 作者 | Wang, Jun1,5; Wang, Qiang1,4,5,6; Sun, Peng1; Dan, Wei1,5 ; Kerr, Andrew C.3; Zhang, Zhi-Ping7; Zhang, Le1,5; Wei, Gangjian1,5; Dong, Han7; Hu, Wan-Long1,5
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| 刊名 | JOURNAL OF PETROLOGY
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| 出版日期 | 2023-08-01 |
| 卷号 | 64期号:8页码:20 |
| 关键词 | crustal growth zircon olivine oxygen isotope Tibet |
| ISSN号 | 0022-3530 |
| DOI | 10.1093/petrology/egad052 |
| 英文摘要 | In recent studies of crustal growth using global zircon Hf-O isotopic datasets, high-& delta;O-18 zircons are typically attributed to intra-crustal reworking during which very little juvenile mantle-derived magmas were added to the crust. Although arc magmas may originate from a high-& delta;O-18 mantle wedge, it has been difficult to decipher the contribution of high-& delta;O-18 mantle to zircon-saturated felsic magma due to superimposed intra-crustal processes. We address this issue by combining the data from high-& delta;O-18 zircon-bearing ultramafic cumulates and coeval lavas from a Cretaceous magmatic arc in southern Tibet. The cumulates mainly consist of different proportions of cumulus olivine and intercumulus amphibole. Amphibole analyses show a transition from increasing to decreasing Zr with increasing SiO2 (50-74 wt.%) contents in the intercumulus melts, indicating zircon saturation in late-stage interstitial melts. The & epsilon;Nd(t) values (2.4 & PLUSMN; 1.4) of the apatite grains crystallized before and after zircon remain almost constant. Interstitial zircons have & delta;O-18 (6.1-7.2 & PTSTHOUSND;) values similar to the earliest crystallized olivine (& delta;O-18 = 6.3-7.1 & PTSTHOUSND;) in the cumulates. The coeval lavas may represent the intercumulus melts extracted from amphibole-rich cumulates at different depths. Both the lavas and cumulates were ultimately derived from high-& delta;O-18 arc mantle modified by small amounts (<12%) of subducted sediments, and crystallized zircon during intra-crustal magma evolution without involving crustal contamination or melting. These high-& delta;O-18 zircons therefore are not products of crustal reworking, but record crustal growth during their crystallization (110 & PLUSMN; 2 Ma). Our study shows that the combination of zircon and olivine oxygen isotopes for ultramafic to felsic rocks is more effective than zircon data alone in evaluating the role of crustal growth vs. reworking in an arc system. The implication is that global zircon-based crustal evolution models that attribute all high-& delta;O-18 zircons to crustal reworking may conceal recent crustal growth. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001038404700001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/74565]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Wang, Qiang |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China 3.Cardiff Univ, Sch Earth & Environm Sci, Cardiff CF10 3AT, Wales 4.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 5.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 6.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Wushan St, Guangzhou 510640, Peoples R China 7.Third Inst Geol & Minerals Explorat, Gansu Prov Bur Geol & Minerals Explorat & Dev, Lanzhou 730050, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang, Jun,Wang, Qiang,Sun, Peng,et al. Crustal Growth Identified by High-& delta;O-18 Zircon and Olivine: A Perspective from Ultramafic Arc Cumulates in Southern Tibet[J]. JOURNAL OF PETROLOGY,2023,64(8):20. |
| APA | Wang, Jun.,Wang, Qiang.,Sun, Peng.,Dan, Wei.,Kerr, Andrew C..,...&Qi, Yue.(2023).Crustal Growth Identified by High-& delta;O-18 Zircon and Olivine: A Perspective from Ultramafic Arc Cumulates in Southern Tibet.JOURNAL OF PETROLOGY,64(8),20. |
| MLA | Wang, Jun,et al."Crustal Growth Identified by High-& delta;O-18 Zircon and Olivine: A Perspective from Ultramafic Arc Cumulates in Southern Tibet".JOURNAL OF PETROLOGY 64.8(2023):20. |
入库方式： OAI收割
来源：广州地球化学研究所
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