编号：CDUT-2023-46

标题：The last Neoproterozoic rift magmatism on the western margin of Yangtze block, South China: New insights of Marinoan onset from low-δ18O magmatic events

入藏号：WOS:000972510700001

中国科学院文献情报中心期刊分区：地球科学2区/TOP（2022）

本校作者：黄长成，邹灏*，陈海锋，于会冬，肖斌，刘春梅，伍江涵，钟怡江，侯明才

来源出版物：Precambrian Research  卷: 390  文献号: 107037 

出版年：2023

第一地址：成都理工大学

关键词：雪球地球；马里诺安；罗迪尼亚超大陆；扬子地块；U-Pb锆石年龄；Hf-O同位素

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摘要：The geological record preserves evidence of “Snowball Earth” glaciations during the Cryogenian Period, the Sturtian onset at ca. 720 Ma and the Marinoan onset at ca. 650 Ma. Compared to the Sturtian, the trigger for the Marinoan is still unclear due to the absence of large igneous provinces (LIPs). This study first discovered low-δ18O Luoluobuzi (LLBZ) granite which emplaced on the eve of the Marinoan at the Yangtze Block in South China. The granite with U-Pb age of 651.2 ± 2.1 Ma and has εHf (t) values between + 6.8 to + 13.3, and low-δ18O values between + 2.74 to + 5.34 ‰. Granite samples show Ba, Nb, Ta, Sr, Eu, and Ti depletion and enrichment in Rb, U, Th, and Pb, modeling calculations to suggest they originated from partial melting of nearby Neoproterozoic mafic rocks and formed in a continental rift. We systematically compiled data and found an interglacial period between the Sturtian-Marinoan glaciations is absent of magmatic activities. Extensional magmatic activity similar to the LLBZ granite started at ca. 651 Ma, which within errorsoverlapped the onset of the Marinoan. Such temporal ruling also existed in other worldwide rift-related magmatic activities. After combining chemical index of alteration (CIA) and palaeomagnetic results, we found the last episode of Rodinia breakup played an important role in the onset of the Marinoan. 

文章链接地址：https://doi.org/10.1016/j.precamres.2023.107037