编号：CDUT-2021-56

标题：A Neoproterozoic low-delta O-18 magmatic ring around South China: Implications for configuration and breakup of Rodinia supercontinent

入藏号：WOS: 000701642300009

中国科学院文献情报中心期刊分区（升级版）：地球科学1区/TOP

本校作者：邹灏；Bagas, Leon；陈安清

来源出版物：EARTH AND PLANETARY SCIENCE LETTERS 卷：575 文献号：117196

出版年：2021年

第一单位：成都理工大学油气藏地质及开发工程国家重点实验室

关键词： low-delta O-18 magmatic ring；Rodinia supercontinent；South China；Yangtze Block

代表图：

摘要：We report Neoproterozoic (ca. 785-780 Ma) granites from the western margin of the Yangtze Block that are characterised by magmatic zircons with delta O-18 values as low as 2.98 parts per thousand. The lack of low-delta O-18 magmatic zircons in the ca. 820-805 Ma rhyolite samples from the Neoproterozoic Suxiong Formation indicates that there is no recycling of pre-existing hydrothermally altered crust in the study area prior to the emplacement of the ca. 785-780 Ma granites. Thus the ca. 785-780 Ma granites with low-delta O-18 values from the western margin of the Yangtze Block can be linked to assimilation of syn-magmatically altered rocks (rather than the assimilation of a pre-existing hydrothermally altered crust). The granites have a source constrained by their depleted Hf isotopes and low-delta O-18 values resulting from high temperature hydrothermal alteration. The delta O-18 values of the zircons from core to rim exhibit a decrease indicative of the remelting of material during the interaction between magma and water at high temperatures. In combination with the widespread low-delta O-18 signatures that occur in the northern and southern margins of the Yangtze Block and Cathaysia Block, the locations of low-delta O-18 magmatic zircons exhibit a Neoproterozoic low-delta O-18 magmatic ring around South China. This continent-scale Neoproterozoic extensional and magmatic event cannot be attributed to subduction processes in South China resulting in the emplacement of a magmatic ring of felsic igneous rocks with low-delta O-18 values. We therefore propose a model involving a Neoproterozoic super-mantle plume with a diameter of approximately 1500 km controlling the development of the rift systems around South China. (C) 2021 Elsevier B.V. All rights reserved.

文章链接地址：https://www.sciencedirect.com/science/article/pii/S0012821X21004519?via%3Dihub