A model of plate kinematics in Gondwana breakup
A model of plate kinematics in Gondwana breakup
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DOI：
10.1111/j.1365-246x.2008.03753.x
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发表时间：
2008-05-01
影响因子：
2.8
通讯作者：
Koenig, Matthias
中科院分区：
文献类型：
--
作者：
Eagles, Graeme;Koenig, Matthias
冈瓦纳板块相对运动的精确模型是基于对里瑟-拉森海和莫桑比克盆地海底等时线和断裂带（FZ）的可视化拟合。预测使用，该模型精确地定位在西索马里盆地的运动学标记，这使得在西索马里和莫桑比克盆地和里瑟-拉森海的扩张中心形成的两个相同的板块之间的边界的一部分的结论。FZ的位置和邻近地区的不太明确的等时线也与它们在同一边界的其他长度上的形成一致，并与M10 n期期间从西索马里盆地和北方纳塔尔谷迁移到西恩德比盆地和拉扎列夫海的情况一致。因此，独立运动的小板块在冈瓦纳大陆核心部分的分裂中没有发挥作用。在反演过程中，来自这些地区的数据产生更精确的有限旋转，描述了两个板块分离的历史。断裂是最简单的解释发生在巧合卡鲁火山作用，和重建的基础上的旋转显示Lebombo和Mateke-Sabi单斜和莫桑比克和阿斯特丽德脊作为两套共轭火山边缘。马达加斯加漂移前的位置可以作为一个约束，以重新评估印度和斯里兰卡在超大陆的位置。
An accurate model of relative plate motions in Gondwana breakup is based on visual fitting of seafloor isochrons and fracture zones (FZ) from the Riiser-Larsen Sea and Mozambique Basin. Used predictively, the model precisely locates kinematic markers in the West Somali Basin, which allows the conclusion that the spreading centres in the West Somali and Mozambique basins and the Riiser-Larsen Sea formed parts of the boundary between the same two plates. The locations of FZ and less well-defined isochrons from neighbouring regions are also consistent with their formation on other lengths of this same boundary and with its relocation from the West Somali Basin and northern Natal Valley to the West Enderby Basin and Lazarev Sea during chron M10n. Small independently moving plates thus played no role in the breakup of this core part of Gondwana. In an inversion procedure, the data from these areas yield more precise finite rotations that describe the history of the two plates' separation. Breakup is most simply interpreted to have occurred in coincidence with Karoo volcanism, and a reconstruction based on the rotations shows the Lebombo and Mateke-Sabi monoclines and the Mozambique and Astrid ridges as two sets of conjugate volcanic margins. Madagascar's pre-drift position can be used as a constraint to reassess the positions of India and Sri Lanka in the supercontinent.