The three-dimensional thermo-mechanical signature of ridge subduction and slab window migration
The three-dimensional thermo-mechanical signature of ridge subduction and slab window migration
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DOI：
10.1016/j.tecto.2008.07.003
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发表时间：
2009-01
期刊：
影响因子：
2.9
通讯作者：
W. Groome;D. Thorkelson
中科院分区：
文献类型：
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作者：
W. Groome;D. Thorkelson
我们提出了一系列三维数值模型，研究了山脊俯冲和板条窗口迁移可能产生的热效应和力学效应。山脊俯冲是板块构造的一个基本过程，在许多收敛的边缘背景下，人们研究了覆盖岩石圈的地质表现。许多板条窗口迁移的地质效应(例如，弧前异常的高温变质作用、火山弧中的非弧状岩浆作用)主要是通过在俯冲带环境中引入热的、上涌的软流圈地幔区域来解释的。利用端元边界条件和理想化几何构型，我们的模型处理了板条窗口迁移的热和相应的力学表现，我们的结果与从解释的板条窗口迁移区域观察到的大体一致。我们的模型表明，弧前区的长期加热应导致持续的高温变质作用，伴随的流变弱化和应变分配，以及受板条窗口迁移影响的区域地形隆起模式的改变。尽管这些模型是理想化的，但它们确实为了解平板窗口环境的地球动力学提供了有价值的见解，并为进一步探索提供了有价值的起点。
We present a series of three-dimensional numerical models investigating possible thermal and mechanical effects of ridge subduction and slab window migration. Ridge subduction is a fundamental process of plate tectonics, and the geologic manifestations in the overriding lithosphere have been investigated in many convergent margin settings. Many of the geologic effects of slab window migration (e.g., anomalous high-T metamorphism in the forearc, non-arc-like magmatism in the volcanic arc) are explained primarily by the introduction of a region of hot, upwelling asthenospheric mantle in the subduction zone environment. Using end-member boundary conditions and idealized geometries, our models address the thermal and corresponding mechanical manifestations of slab window migration, and our results provide a general agreement with observations from interpreted regions of slab window migration. Our models show that protracted heating in the forearc region should result in protracted high-temperature metamorphism, associated rheologic weakening and strain partitioning and changes in the topographic uplift pattern in regions affected by slab window migration. Although these models are idealized, they do provide valuable insight into the geodynamics of slab window environments and provide a valuable starting point for further exploration.