Geochronology of Neoproterozoic mafic rocks and sandstones from northeastern Guizhou, South China: Coeval arc magmatism and sedimentation
Geochronology of Neoproterozoic mafic rocks and sandstones from northeastern Guizhou, South China: Coeval arc magmatism and sedimentation
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华南黔东北新元古代镁铁质岩和砂岩的年代学：同时代弧岩浆作用和沉积作用
DOI：
10.1016/j.precamres.2008.11.002
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发表时间：
2009-04
影响因子：
3.8
通讯作者：
中科院分区：
文献类型：
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作者：
The mafic–ultramafic rocks in the Fanjingshan Group from northeastern Guizhou have been classified as the calc-alkaline series. These mafic rocks have prominent negative Nb, Ta and Ti but positive Pb anomalies and show typical geochemical signatures of arc basalts and decoupling Nd–Hf isotopic characters. SHRIMP and LA-ICP-MS U–Pb zircon datings for four samples of the mafic rocks yield U–Pb zircon ages of 814±15Ma, 814±6Ma, 831±6Ma and 827±24Ma with an average age of 822±15Ma. The U–Pb ages of the youngest detrital zircon grains in four samples of the sandstones from the Fanjingshan Group are 873±4Ma, 874±10Ma, 870±10Ma and 869±9Ma with an average age of 872±3Ma that is considered as the maximum depositional age of these sandstones. It suggests that the Fanjingshan Group, the equivalent of the Sibao and Lengjiaxi Groups occurring in the western Jiangnan orogen, is Neoproterozoic rather than Mesoproterozoic as previously considered. Combined with published age data, the U–Pb zircon dating of both mafic rocks and sandstones in the Fanjingshan Group provides new constraints on the timing of various geological events during the development of the Jiangnan orogen. It is evident that there existed coeval magmatism (878–822Ma) with arc signatures and sedimentation (872–835Ma) in the foreland basin along the southeastern margin of the Yangtze Block during the Neoproterozoic. Compared with the Grenvillian-age orogenic event, the collision between the Yangtze and Cathaysia Blocks was postponed for 355–160Ma. Moreover, the basement strata in the Jiangnan orogen underwent thorough greenschist-facies metamorphism. The prevalent granulite-facies metamorphism in the Grenvillian orogenic belts has not been found in the metamorphosed sedimentary-igneous rocks of the basement strata exposed in the Jiangnan orogen. All these suggest that the Jiangnan orogen should not be considered as a Grenvillian-age orogenic belt. It is proposed that the Jiangnan orogen might be the product of collision between two neighboring blocks during the transition of Rodinia to Gondwana.
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DOI：
--
发表时间：
2003
期刊：
--
影响因子：
--
作者：
Zhou Jin-cheng
通讯作者：
Zhou Jin-cheng
影响因子：
--
作者：
Jian Wang;Xian‐Hua Li;T. Duan;Dunyi Liu;B. Song;Zhongxiong Li;Yonghua Gao
通讯作者：
Jian Wang;Xian‐Hua Li;T. Duan;Dunyi Liu;B. Song;Zhongxiong Li;Yonghua Gao
DOI：
--
发表时间：
2001
期刊：
Journal of Mineralogy and Petrology
影响因子：
--
作者：
W. Jian
通讯作者：
W. Jian
影响因子：
3.8
作者：
Shao‐Bing Zhang;Yong Zheng;Y. Wu;Zi‐Fu Zhao;Shan Gao;Fu-Yuan Wu
通讯作者：
Shao‐Bing Zhang;Yong Zheng;Y. Wu;Zi‐Fu Zhao;Shan Gao;Fu-Yuan Wu
影响因子：
56.9
作者：
E. Scherer;C. Münker;K. Mezger
通讯作者：
E. Scherer;C. Münker;K. Mezger