Tectonic structure across the accretionary and erosional parts of the Japan Trench margin
Tectonic structure across the accretionary and erosional parts of the Japan Trench margin
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日本海沟边缘增生和侵蚀部分的构造结构
DOI：
10.1029/94jb01198
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发表时间：
1994
影响因子：
--
通讯作者：
John J. Miller
中科院分区：
文献类型：
--
作者：
R. Huene;D. Klaeschen;B. Cropp;John J. Miller
叠前深度偏移地震资料的横贯日本海沟构造剖面确定了大陆格架的增生棱柱、楔形向海端以及它们之间构造化的中间斜坡。10公里宽的增生棱镜被俯冲的海洋地壳留下的沉积物冲断。陡峭的中间斜坡下的构造更接近相邻的大陆边缘，而不是增生的地块。这个变形的中斜坡区域在顺从的增生楔和更坚硬的旧大陆格架之间形成了一个缓冲带。沿着板块边界，中上部斜坡下的俯冲地层变厚，最后一次成像的地方，是增生棱镜下输入厚度的四倍。这个板块间分层层似乎控制着板块间的摩擦，因为该层的成像是从海沟轴向陆地45公里到12公里深的地方，在这片广阔的土地上，很少记录到上层板块的地震。中大陆坡下板块底部的侵蚀表现为边缘沉降和物质通量。这种侵蚀与边缘前部的增生同时发生。
Structure sections across the Japan Trench from prestack depth migrated seismic data define the accretionary prism, a wedge-shaped seaward end of the continental framework, and a tectonized middle slope between them. The 10-km-wide accretionary prism is underthrust by sediment remaining with the subducted oceanic crust. Structure beneath the steep middle slope more nearly resembles the adjacent continental margin than the accreted mass. This deformed middle slope domain forms a buffer between the compliant accretionary wedge and a more rigid older continental framework. Along the plate boundary, subducted strata thicken beneath the middle and upper slopes and, where last imaged, are four times the input thickness beneath the accretionary prism. This interplate stratified layer appears to control interplate friction because the layer is imaged 45 km landward from the trench axis to 12-km depth and in that expanse, few upper plate earthquakes are recorded. Erosion of the base of the upper plate beneath the middle continental slope is indicated by margin subsidence and material flux. This erosion is concurrent with accretion at the front of the margin.