850-790 Ma bimodal volcanic and intrusive rocks in northern Zhejiang, South China: A major episode of continental rift magmatism during the breakup of Rodinia
850-790 Ma bimodal volcanic and intrusive rocks in northern Zhejiang, South China: A major episode of continental rift magmatism during the breakup of Rodinia
复制标题
华南浙北850-790Ma双峰式火山岩和侵入岩：罗迪尼亚裂解过程中大陆裂谷岩浆作用的一次重要事件
DOI：
10.1016/j.lithos.2007.04.007
复制
发表时间：
2008-04-01
期刊：
影响因子：
3.5
通讯作者：
Liu, Ying
中科院分区：
文献类型：
--
作者：
Li, Xian-Hua;Li, Wu-Xian;Liu, Ying
报道了浙江北方中新元古代火成岩的锆石SHRIMP U-Pb年龄、地球化学和Nd同位素数据。神雾粗玄岩脉、道林山花岗闪长岩杂岩和尚书双峰式（玄武岩-流纹岩）火山岩的年龄分别为849 +/- 7 Ma、794 +/- 9 Ma和792 +/- 5 Ma。所有研究的镁铁质岩石拉斑玄武岩的成分和表现出整体适度富集最不相容的微量元素，类似于大陆裂谷板内玄武岩。类似于850 Ma神屋粗粒岩是距今850 Ma以来发现的最早的非造山玄武岩。1.1-0.9 Ga的四堡造山运动，但似乎早于新元古代裂谷。我们的结果显然与扬子地块南缘沿着存在活动大陆边缘直到约2000年的另一种构造模式不同。八百毫安。密集的类似790马双峰火山岩和深成岩，一个主要阶段的中新元古代裂谷的一部分，同时广泛的中新元古代板内岩浆活动在整个华南。它们最有可能与导致Rodinia超大陆分裂的地幔超柱有关。(c)2007 Elsevier B. V.保留所有权利。
SHRIMP U-Pb zircon ages and geochemical and Nd isotopic data are reported for mid-Neoproterozoic igneous rocks in northern Zhejiang Province, South China. The Shenwu dolerite dykes, the Daolinshan granite-diabase complex, and the Shangshu bimodal (basalt-rhyolite) volcanic rocks were dated at 849 +/- 7 Ma, 794 +/- 9 Ma and 792 +/- 5 Ma, respectively. All the studied mafic rocks are tholeiitic in compositions and exhibit overall moderate enrichments in most incompatible trace elements, resembling intraplate basaltic rocks in continental rifts. The similar to 850 Ma Shenwu dolerites are the earliest anorogenic basaltic rocks identified so far after the ca. 1.1-0.9 Ga Sibao Orogeny, but seem to predate the Neoproterozoic rifting. Our results are clearly at variance with the alternative tectonic model that an active continental margin existed along the southern margin of the Yangtze Block until ca. 800 Ma. The intensive similar to 790 Ma bimodal volcanic and plutonic rocks, part of a major phase of mid-Neoproterozoic rifting, are concurrent with the widespread mid-Neoproterozoic intraplate magmatism throughout South China. They are most likely related to the proposed mantle superplume that led to the breakup of the supercontinent Rodinia. (c) 2007 Elsevier B.V. All rights reserved.