Reconstruction of Early Paleozoic arc-trench system: a case study in the eastern Gondwana margin

早古生代弧沟系统的重建——以冈瓦纳大陆边缘东部为例

• 批准号: 10041102
• 负责人: WATANABE Teruo
• 金额: $ 7.23万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10041102/
• 关键词: Gondwana; Rodinia; eclogite; Serpentinite melange; Australia; arc-trench system; Gondwana; Rodinia; U-Pb SHRIMP年代; Sm-Nd年代; Ar-Ar法; 古生代前期; 蛇紋岩メランジ帯; 原生代後期-古生代初期; 島弧; ニューイングランド褶曲帯; MORB,SHRIMP年代

The target of our research is to reconstruct the Early Paleozoic arc-trench system along the eastern margin of Gondwanaland. However, the chronological results on Attunga eclogite and host gabbro in the serpentinite melange yield a range from 660Ma to 460Ma zircon U-Pb SHRIMP gaes with 660Ma, thus the time span for rearch has been expanded to Neoproterozoic. Tectonics of Neoproterozoic along the later Gondwana eastern margin include those of breakup process of the Rodinia supercontinient . We obtain the following results1) We propose a model of the Phillipne type for Early Paleozoic Gondwana margin.2) In Latest Neoproterozoic, a subduction zone was produced. Simultneously, a rifting and opening of an ocean in the Kanmantoo Fold Belt occurred in the Eastern Gondwana part.3) Serpentinite melange includes various kinds or igneous and metamorphic rocks. Their ages range from Neoproterozoic to Early Mesozoic.4) During the Rodinia breakup, petrochemical evidence of mantle plume activity is obatained.After the breakup, arc systems were formed firstly in SW Siberia and then Australia.

我们研究的目标是重建冈瓦纳兰东部边缘的早古生代弧沟系统。然而，在蛇状属混合物中的attunga eclogite和宿主gabbro的时间顺序结果产生的范围从660mA到460ma锆石U-PB虾gaes，其含量为660mA，因此Rearch的时间跨度已扩展到Neoperoteroteroterocic。后来的冈瓦纳东部边缘沿新元古代的构造学包括Rodinia Supercontinient的分手过程。我们获得以下结果1）我们提出了一种早期古生代冈瓦纳边缘的菲律宾类型的模型。2）在最新的Neoroperozoic中，产生了一个俯冲带。同时，在冈瓦纳东部部分发生了坎曼图褶皱带的海洋的裂谷和开口。3）Serpentinite Melange包括各种或火成岩和变质岩石。它们的年龄范围从新元古代到早期的中生代。4）在罗迪尼（Rodinia）破裂期间，质量羽流活性的石化证据被服从。分解后，ARC系统首先在SW西伯利亚和澳大利亚形成。