文献类型：期刊文献

英文题名：Middle Tonian calc-alkaline picrites, basalts, and basaltic andesites from the Jiangnan Orogen: Evidence for rear-arc magmatism

作者：Zhang, Jiawei Liao, Mingyang Santosh, M. Yang, Zhongqing Zhang, Ying Dai, Yaran

第一作者：Zhang, Jiawei

通信作者：Zhang, JW[1];Liao, MY[2]|[14440e6625cc8a974db0b]廖名扬;

机构：[1]Guizhou Geol Survey, Bur Geol & Mineral Explorat & Dev Guizhou Prov, Guiyang 550081, Peoples R China;[2]Minist Nat Resources, Technol Innovat Ctr Mineral Resources Explorat En, Guiyang 550081, Peoples R China;[3]Guizhou Inst Technol, Guiyang 550003, Peoples R China;[4]China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China;[5]Univ Adelaide, Dept Earth Sci, Adelaide, SA 5005, Australia;[6]Yonsei Univ, Yonsei Frontier Lab, Seoul, South Korea

第一机构：Guizhou Geol Survey, Bur Geol & Mineral Explorat & Dev Guizhou Prov, Guiyang 550081, Peoples R China

通信机构：corresponding author), Guizhou Geol Survey, Bur Geol & Mineral Explorat & Dev Guizhou Prov, Guiyang 550081, Peoples R China;corresponding author), Guizhou Inst Technol, Guiyang 550003, Peoples R China.|贵州理工学院;

年份：2020

卷号：350

外文期刊名：PRECAMBRIAN RESEARCH

收录：;Scopus(收录号：2-s2.0-85091797010);WOS:【SCI-EXPANDED(收录号:WOS:000589423600046)】；

基金：Financial supports from National Natural Science Foundations of China (41603039 and 41963006) to Jiawei Zhang, Geosciences Research Foundation of Bureau of Geology and Mineral Exploration and Development Guizhou Province, China (QDKKH[2016]34, QDKKH[2019]22), and Guizhou Scientific and Technology Planning Project, China (QKHPTRC[2018]5626) are gratefully acknowledged. Professors Chusi Li, Runsheng Yin, Dan Zhu and Yan Tao are appreciated for improving the academic and English qualities of the manuscript. We are indebted to four anonymous reviewers and editor Guochun Zhao for their constructive comments. Thanks are given to Lei Shi, Haibo Li, and Lei Lu from the Fanjingshan World Natural Heritage Administration for their assistances during the field trips.

语种：英文

外文关键词：Neoproterozoic; Mantle potential temperature; Fanjingshan; Yangtze Block; Plate tectonic setting

摘要：The chemical composition of a basalt is a critical indicator of mantle thermal condition and tectonic setting. The Yangtze Block, which is a part of the Rodinia supercontinent, formed during the Neoproterozoic era presents an enigmatic thermal state of the mantle and tectonic evolution. We compiled a large database of petrogeochemical data on the Middle Tonian volcanic rocks covering the entire Jiangnan Orogen with a view to evaluate the evolution of the magma compute the composition of the primary magma, estimate the mantle potential temperature (T-p), and distinguish the tectonic setting. Calc-alkaline picrites, basalts, and basaltic andesites (type A) from ca. 845-825 Ma and tholeiitic basalts (type B) from ca. 860-830 Ma were both identified as interbedded layers accompanied with the Middle Tonian sedimentary sequences (the Fanjingshan Group and its equivalents) and geographically intersecting with each other along the Jiangnan Orogen. Geochemical and isotopic features of type A volcanic rocks indicate that they originated from an enriched mantle source. Both slab-derived fluids and fractionation of olivine and clinopyroxene played important roles during magma generation and evolution. The calculated composition of the primary magma is picritic and the estimated average T-p is 1404 degrees C. This temperature is consistent with the melting of a mantle wedge due to a rapid slab roll-back process, but it is lower by 166 degrees C than that produced by a hot mantle plume. Considering the occurrence of the continental arc basalts (CAB)-like type A volcanic rocks and the back-arc basin basalts (BABB)-like type B basalts along with contemporaneous sedimentary sequences with the bidirectional detritus sources in the Jiangnan Orogen, we hereby speculate a rear-arc setting for type A volcanic rocks and a back-arc setting for Type B basalts.