(Table 1) Results from XRD analysis as well as sediment type and selected results from ring shear experiments

The location of the seaward tip of a subduction thrust controls material transfer at convergent plate margins, and hence global mass balances. At approximately half of those margins, the material of the subducting plate is completely underthrust so that no accretion or even subduction erosion takes place. Along the remaining margins, material is scraped off the subducting plate and added to the upper plate by frontal accretion. We here examine the physical properties of subducting sediments off Costa Rica and Nankai, type examples for an erosional and an accretionary margin, to investigate which parameters control the level where the frontal thrust cuts into the incoming sediment pile. […]

海沟推覆体的外侧端点位置控制了汇聚板块边缘的物质迁移，进而影响全球质量平衡。在这些边缘中，大约一半的地区，俯冲板块的物质完全被推覆，因此未发生任何堆积或甚至俯冲侵蚀。在剩余的边缘，物质被从俯冲板块上刮落，并通过前沿堆积添加到上板块。本研究旨在考察位于哥斯达黎加和南海的俯冲沉积物的物理性质，它们分别代表了侵蚀型和堆积型边缘的典型实例，以探究哪些参数控制了前沿推覆切割入 incoming 沉积堆的高度。