The role of arc migration in the development of the Lesser Antilles: A new tectonic model for the Cenozoic evolution of the eastern Caribbean
The role of arc migration in the development of the Lesser Antilles: A new tectonic model for the Cenozoic evolution of the eastern Caribbean
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DOI：
10.1130/g46708.1
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发表时间：
2019-09-01
期刊：
影响因子：
5.8
通讯作者：
Wilson, Marjorie
中科院分区：
文献类型：
--
作者：
Allen, R. W.;Collier, J. S.;Wilson, Marjorie
大陆弧系统经常显示出朝向和远离传入板块的大规模迁移的证据。然而，在大洋弧系统中，虽然板片回滚和相关的弧后扩张和弧向传入板块迁移的过程是常见的，但很少观察到弧迁移远离传入板块。我们提出了一个新的海洋磁异常和地震数据的汇编，以提出一个新的构造模型，东加勒比地区，包括在两个方向的弧迁移。我们综合了新的证据，显示两个阶段的弧后扩张和向东向传入大西洋的弧迁移。第三个也是最后一个阶段的弧向西迁移细分了早期的弧后盆地的两侧，今天的小安的列斯群岛弧。这是第一个在洋内环境中区域性多方向弧迁移的例子，它对沿弧构造和地球化学变化具有影响。弧的来回迁移可能是由于邻近的美洲板块对这个孤立的俯冲系统的限制，而不是俯冲板浮力的变化。
Continental arc systems often show evidence of large-scale migration both toward and away from the incoming plate. In oceanic arc systems, however, while slab roll-back and the associated processes of backarc spreading and arc migration toward the incoming plate are commonplace, arc migration away from the incoming plate is rarely observed. We present a new compilation of marine magnetic anomaly and seismic data in order to propose a new tectonic model for the eastern Caribbean region that includes arc migration in both directions. We synthesized new evidence to show two phases of backarc spreading and eastward arc migration toward the incoming Atlantic. A third and final phase of arc migration to the west subdivided the earlier backarc basin on either side of the present-day Lesser Antilles arc. This is the first example of regional multidirectional arc migration in an intra-oceanic setting, and it has implications for along-arc structural and geochemical variations. The back and forth arc migrations were probably due to the constraints imposed by the neighboring American plates on this isolated subduction system, rather than variations in subducting slab buoyancy.