Recognition of Late Carboniferous arc-related volcanic rocks from Ongniud Banner, southeastern Inner Mongolia: Evidence of southward subduction and implication of closure time for Palaeo-Asian Ocean,Geological Journal

当前位置： X-MOL 学术 › Geolog. J. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Recognition of Late Carboniferous arc-related volcanic rocks from Ongniud Banner, southeastern Inner Mongolia: Evidence of southward subduction and implication of closure time for Palaeo-Asian Ocean
Geological Journal ( IF 1.4 ) Pub Date : 2021-06-06 , DOI: 10.1002/gj.4188
Jiyu Du _{1,

2} , Nan Tao ₂ , Bin Jiang ₂ , Yan Wang ₂ , Weimin Song ₂ , Cheng Qian ₂ , Xiaoping Yang ₂ , Yujin Zhang ₂ , Shiwei Chang ₃

Affiliation

Newly recognized Late Carboniferous volcanic rocks occur in Ongniud Banner on the northern margin of the Sino-Korean palaeoplate, including rhyolite, dacite, and related volcaniclastic. The volcanic rocks have for a long time been considered to form in the Early Permian. Our new LA-ICP-MS U–Pb zircon dating of two rhyolite samples and one dacite sample yielded ages of 305.6 ± 1.6 Ma, 312.2 ± 2.3 Ma, and 305.3 ± 1.7 Ma, respectively, corresponding to the Late Carboniferous. The volcanic rocks are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) and depleted in heavy rare earth elements (HREEs) and high-field-strength elements (HFSEs, e.g., Nb, Ta). The positive zircon ε_Hf(t) values (+6.64 to +9.49) of the volcanic rocks and the high Mg^# values (47.05–51.47) of some samples indicate the contribution of mantle materials to the sources. Integrated with geological, geochemical, and Lu–Hf isotopic studies, it is considered the volcanic rocks formed in a subduction-related continental margin arc setting. Combined with the studies in the southeastern part of the Central Asian Orogenic Belt on the ophiolitic mélanges, magamatic belts and sedimentary environment of the Late Palaeozoic, collision-related granites, and so on; it is suggested that the southward subduction for the eastern segment of the Palaeo-Asian Ocean beneath the northern margin of Sino-Korean palaeoplate was still occurring in the Late Carboniferous.

中文翻译：

内蒙古东南部翁牛旗晚石炭世弧相关火山岩的识别：古亚洲洋向南俯冲的证据及闭合时间的意义

新发现的晚石炭世火山岩位于中朝古板块北缘的翁牛旗，包括流纹岩、英安岩和相关火山碎屑岩。长期以来，人们认为火山岩形成于早二叠世。我们对两个流纹岩样品和一个英安岩样品的新 LA-ICP-MS U-Pb 锆石测年结果分别为 305.6 ± 1.6 Ma、312.2 ± 2.3 Ma 和 305.3 ± 1.7 Ma，对应于晚石炭世。火山岩富含轻稀土元素（LREEs）和大离子亲石元素（LILEs），贫乏重稀土元素（HREEs）和高场强元素（HFSEs，如Nb、Ta）。正锆石ε _Hf ( t) 值 (+6.64 至 +9.49) 和一些样品的高 Mg ^#值 (47.05-51.47) 表明地幔物质对源的贡献。结合地质、地球化学和 Lu-Hf 同位素研究，它被认为是在与俯冲相关的大陆边缘弧环境中形成的火山岩。结合中亚造山带东南部蛇绿混杂岩、岩浆带、晚古生代沉积环境、碰撞相关花岗岩等研究；表明中朝古板块北缘下古亚洲洋东段的南俯冲作用在晚石炭世仍在发生。

更新日期：2021-06-06

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11