Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Tao ZaiLi1,2; Yin JiYuan1; Yuan Chao3 ; Xiao WenJiao4,5; Chen Wen1; Chen YueLong1; Wang YaMei1,2; Yang Fan1,2
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| Petrogenesis of Late Ordovician intrusive rocks in the West Kunlun orogenic belt: Constraints on the subduction process of the Proto-Tethys Ocean | |
| Source Publication | ACTA PETROLOGICA SINICA
 |
| ISSN | 1000-0569 |
| 2022-11-01 | |
| Volume | 38Issue:11Pages:3321-3340 |
| DOI | 10.18654/1000-0569/2022.11.05 |
| Language | 英语 |
| WOS Research Area | Geology |
| Abstract | The Early Paleozoic magmatic rocks are widespread in the West Kunlun orogenic belt, and their formation is genetically linked to the subduction-collision of the Proto-Tethys Ocean. However, the petrogenesis of these magmatic rocks and their tectonic setting remain controversial. In this paper, we present new zircon U-Pb ages, whole -rock geochemistry, Sr-Nd isotopic and zircon HfO isotopic data of the Early Paleozoic Arkarz monzonite and Saitula quartz -diorite in the West Kunlun orogenic belt to reveal their magma sources and explore the evolution process of the Proto-Tethys Ocean. Zircon U-Pb dating reveals that the two plutons are formed during the Late Ordovician, with the ages of 456 +/- 2Ma and 452 +/- 2Ma, respectively. The Arkarz monzonite samples are characterized by high alkali contents ( K2O + Na2O = 10.5% similar to 11. 8%) with potassium -rich ratios ( K2O/Na2O = 1.20 similar to 1. 44), and low MgO (0. 89% similar to 0. 97%) and TiO2(0. 42% similar to 0. 45%) contents, demonstrating that they belong to potassic alkaline rocks. Furthermore, they are enriched in large ion lithophile elements ( LILEs; Rb, Th, U), and have high zircon saturation temperatures ( T-zr = 814 similar to 862 degrees C). In addition, the monzonites have high (Sr-87/Sr-86), (0. 72057 similar to 0. 72186), negative whole -rocks epsilon(Nd) ( t) ( -5. 1 similar to - 4. 5) and zircon e(Hf) ( t) ( -7. 6 similar to - 3. 4) and high zircon delta O-18 (5. 39% similar to 7. 94%o) values, suggesting that they could be the partial melting products of the ancient mafic lower crust at an extensional setting. The Saitula quartz diorites have SiO2 contents of 56.8% similar to 58.6%, total alkali contents of 5. 75% similar to 6. 39%, with a low aluminum saturation index ( A/CNK = 0. 85 similar to 0. 89), as well as relatively high MgO contents (2. 93% similar to 3. 41%) and Mg# values ( ca. 45), which is consistent with the geochemical features of high potassium calcalkaline series. Furthermore, they are enriched in large ion lithophile elements ( e. g., Rb, Ba, Th) and light rare earth elements, and depleted in high field strength elements ( e. g., Nb, Ta and Ti), with weak Eu anomalies ( Eu/Eu* = 0. 72 similar to 0. 77), which is similar to those of magmatic rocks formed in the subduction zone. These quartz diorite samples have relatively high (87Sr/86Sr), ratios (0.71317 similar to 0.71322), negative whole -rocks epsilon(Nd)(t) ( -5. 1 similar to -5. 6) and negative zircon eHf (t) ( -7. 8 similar to -2. 9) values, which is similar to the isotopic characteristics of mafic rocks of the enriched mantle. These characteristics suggest that the Saitula quartz diorite was derived from the partial melting of an enriched mantle wedge that had been metasomatized by subduction-related fluids, and afterwards, fractional crystallization of olivine, pyroxene, amphibole, apatite and Fe -Ti oxide occurred during its magmatic evolution. The results of isotope and Rhyolite-MELTS modeling imply that they were likely produced by fractional crystallization of basaltic rocks in the southern margin of Tarim Craton. Combined with regional geological data, we conclude that the Late Ordovician Arkarz monzonite and Saitula quartz -diorite were formed in an Andean -type active continental margin related to the northward subduction of the Proto-Tethys oceanic slab. During this period, the subducting slab began to roll -back, resulting in the upwelling of the asthenosphere mantle and a large number of arc magmatic rocks. |
| Keyword | West Kunlun orogenic belt Proto-Tethys Ocean Ordovician Enriched mantle wedge Slab rollback |
| WOS ID | WOS:000905326500005 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/72567 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Yin JiYuan |
| Affiliation | 1.Chinese Acad Geol Sci, Inst Geol, Minist Nat Resources, Key Lab Deep Earth Dynam, Beijing 100037, Peoples R China 2.China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China 3.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 4.Chinese Acad Sci, Xinjiang Inst Ecol & Geog, Xinjiang Res Ctr Mineral Resources, Urumqi 830011, Peoples R China 5.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China |
| Recommended Citation GB/T 7714 | Tao ZaiLi,Yin JiYuan,Yuan Chao,et al. Petrogenesis of Late Ordovician intrusive rocks in the West Kunlun orogenic belt: Constraints on the subduction process of the Proto-Tethys Ocean[J]. ACTA PETROLOGICA SINICA,2022,38(11):3321-3340. |
| APA | Tao ZaiLi.,Yin JiYuan.,Yuan Chao.,Xiao WenJiao.,Chen Wen.,...&Yang Fan.(2022).Petrogenesis of Late Ordovician intrusive rocks in the West Kunlun orogenic belt: Constraints on the subduction process of the Proto-Tethys Ocean.ACTA PETROLOGICA SINICA,38(11),3321-3340. |
| MLA | Tao ZaiLi,et al."Petrogenesis of Late Ordovician intrusive rocks in the West Kunlun orogenic belt: Constraints on the subduction process of the Proto-Tethys Ocean".ACTA PETROLOGICA SINICA 38.11(2022):3321-3340. |
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