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DOI | 10.1007/s00531-020-01824-w |
Prolonged Neo-Tethyan magmatic arc in Myanmar: evidence from geochemistry and Sr-Nd-Hf isotopes of Cretaceous mafic-felsic intrusions in the Banmauk-Kawlin area | |
Li, Jin-Xiang; Fan, Wei-Ming; Zhang, Li-Yun; Peng, Tou-Ping; Sun, Ya-Li; Ding, Lin; Cai, Fu-Long; Sein, Kyaing | |
通讯作者 | Li, JX (通讯作者) |
发表日期 | 2020 |
ISSN | 1437-3254 |
EISSN | 1437-3262 |
起始页码 | 649 |
结束页码 | 668 |
卷号 | 109期号:2 |
英文摘要 | Cretaceous mafic-felsic intrusions are extensively distributed in the West Burma terrane (Myanmar), but their petrogenesis and tectonic setting still remain unclear. In this study, whole-rock geochemical and Sr-Nd as well as zircon U-Pb and Hf isotopic data for the Cretaceous mafic-felsic intrusions from the Banmauk-Kawlin area (northern Myanmar) are presented. Precise zircon U-Pb dating results indicate that they emplaced at Cretaceous ( 110-90 Ma) and likely belong to an eastward extension of the coeval Gangdese magmatic belt in the southern Lhasa terrane (Tibet). The studied Cretaceous intrusions (SiO2 = 41.97 to 74.54 wt%) mostly have calc-alkaline and Na-rich characteristics, and strong enrichments in large ion lithophile elements (e.g., Cs, Rb, and K), depletions in Nb and Ta on primitive mantle-normalized diagrams, consistent with geochemical characteristics of arc-type magmas. Most of Cretaceous gabbroic and dioritic intrusions with relatively depleted mantle Sr-Nd-Hf isotopic compositions (Sr-87/Sr-86(i) = 0.7041-0.7048, epsilon Nd(t) = 0.2-6.8, and epsilon Hf(t) = 4.3-15.1) and high Ba/La ratios were possibly derived from partial melting of mantle wedge metasomatized by slab-derived fluids and underwent a certain degree of fractional crystallization. Whereas Cretaceous granodiorite and granite probably formed by partial melting of juvenile arc lower crust on the basis of positive epsilon Nd(t)-epsilon Hf(t) values (- 2.4 to 6.6 and - 2.8 to 15.3) and low initial Sr isotopic ratios (Sr-87/Sr-86(i) = 0.7045-0.7063). A wide range of Th/Nb ratios and Sr-Nd-Hf isotopic values in these intrusions suggests that their juvenile arc lower crust possibly formed by melting of slab-derived fluids and/or sediment melts metasomatized mantle. Overall, Cretaceous ( 110-90 Ma) mafic-felsic intrusions in the West Burma terrane may have formed in an arc setting during subduction of the Neo-Tethyan oceanic lithosphere, suggesting a prolonged Neo-Tethyan magmatic arc system from southern Tibet to Southeast Asia. |
关键词 | ZIRCON U-PBJURASSIC VOLCANIC-ROCKSA-TYPE GRANITESTECTONIC EVOLUTIONSOUTHERN TIBETLU-HFYEBA FORMATIONCALC-ALKALINECONSTRAINTSGANGDESE |
英文关键词 | Cretaceous; Neo-Tethyan magmatic arc; Mafic-felsic intrusions; Banmauk-Kawlin area; Myanmar |
语种 | 英语 |
WOS研究方向 | Geology |
WOS类目 | Geosciences, Multidisciplinary |
WOS记录号 | WOS:000511060300001 |
来源期刊 | INTERNATIONAL JOURNAL OF EARTH SCIENCES |
来源机构 | 中国科学院青藏高原研究所 |
文献类型 | 期刊论文 |
条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/259853 |
推荐引用方式 GB/T 7714 | Li, Jin-Xiang,Fan, Wei-Ming,Zhang, Li-Yun,et al. Prolonged Neo-Tethyan magmatic arc in Myanmar: evidence from geochemistry and Sr-Nd-Hf isotopes of Cretaceous mafic-felsic intrusions in the Banmauk-Kawlin area[J]. 中国科学院青藏高原研究所,2020,109(2). |
APA | Li, Jin-Xiang.,Fan, Wei-Ming.,Zhang, Li-Yun.,Peng, Tou-Ping.,Sun, Ya-Li.,...&Sein, Kyaing.(2020).Prolonged Neo-Tethyan magmatic arc in Myanmar: evidence from geochemistry and Sr-Nd-Hf isotopes of Cretaceous mafic-felsic intrusions in the Banmauk-Kawlin area.INTERNATIONAL JOURNAL OF EARTH SCIENCES,109(2). |
MLA | Li, Jin-Xiang,et al."Prolonged Neo-Tethyan magmatic arc in Myanmar: evidence from geochemistry and Sr-Nd-Hf isotopes of Cretaceous mafic-felsic intrusions in the Banmauk-Kawlin area".INTERNATIONAL JOURNAL OF EARTH SCIENCES 109.2(2020). |
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