国家科技基础条件平台
  • 你好,请
  • 登录
    • logotext
    Zircon SHRIMP U-Pb dating for the Cangshuipu volvanic rocks and its implications for the lower boundary age of the Nanhua strata in South China [查看] WANGJian、LIXianhua、DUANTaizhong、LIUDunyi、SONGBiao、LIZhongxiong、GAOYonghua
    Abstract The continental volcanic rocks and volcaniclastic sedimentary conglomerates of the Cangshuipu Formation occur well in Yiyang of Hunan Province, consisting of a wedge-shaped succession of Neoproterozoic strata that overlie with high-angle unconformity the flysch turbidites of the Lengjiaxi Group in the Upper Mesoproterozoic Eonothem.SHRIMP zircon U-Pb dating gives a weighted mean age of 814 ± 12 Ma for the dacitic volcanic agglomerates from the lowest part of the volcanic rocks in the Cangshuipu Formation.This age is younger than previously reported values of 921—933 Ma for the volcanic rocks from the Cangshuipu Formation. Our new dating represents the lower boundary age of the Neoproterozoic System in the studied area. The younger age for the Cangshuipu volcanic rocks is supported by the following observations: (1) Lower Neoproterozoic strata (814—1000 Ma) are missing in the studied area; (2) the Nanhua rift system was initiated at about 820 Ma; and(3) an age of ~820 Ma may be taken as the lower boundary timing of the Nanhua System (even Neoproterozoic) in South China.
    SHRIMP U-Pb zircon age, geochemistry and Nd isotope of the Guandaoshan pluton in SW Sichuan Petrogenesis and tectonic significance [查看] LIXianhua、LIZhengxiang、ZHOUHanwen、LIUYing、LIANGXirong、LIWuxian
    Abstract SHRIMP U-Pb zircon age, geochemical and Nd isotopic data are reported for the Neoproterozoic Guandaoshan pluton in the Yanbian region, SW Sichuan. This pluton is of typical I-type granite and emplaced at (857 ± 13) Ma. Geochemical and Nd isotopic characters suggest that the pluton was generated by partial melting of pre-existing, young (late Mesoproterozoic to early Neoproterozoic) low-K tholeiitic protolith within an intraplate anorogenic setting. The Guandaoshan pluton probably records the earliest magmatism induced by the proposed ca. 860–750 Ma mantle superplume beneath the supercontinent Rodinia.
    SHRIMP U-Pb zircon dating of the uppermost Cretaceous Furao Formation near the Heilong River：An age chosest to the KT boundary [查看] LIXianhua、LIWuxian、CHENPeiji、WANXiaoqiao、LIGang、SONGBiao、JIANGJianhong、LIUJicai、YINDeshun、YANWei
    SHRIMP U-Pb zircon age of the Jinchuan ultramafic intrusion and its geological significance [查看] LIXianhua、SULi、SONGBiao、LIUDunyi
    © BJSHRIMP 2013 - bjshrimp.cn