Collaborative Research: Active Out-of-Sequence Thrusting in the Fila Costena Thrust Belt, Pacific Costa Rica

现在人们普遍认识到，会聚边缘可能经历增生或俯冲侵蚀，其速度取决于多种因素。吸积楔生长的过程有很好的文献记载，然而，吸积楔侵蚀的过程则更加神秘。该项目将检查哥斯达黎加的太平洋海岸，并评估目前的速度和与中美洲海沟内前弧活动逆冲断层相关的总缩短——这些断层允许通过外前弧的逆冲作用进行俯冲侵蚀。结果将用于评价在粗糙地壳和浅俯冲的地区，是否存在从楔尖向楔内部快速缩短的拱移位置。这项工作有望增加对吸积楔如何侵蚀的认识。

9909699 Fisher9909375 GardnerIt is now widely recognized that convergent margins can experience accretion or subduction erosion with rates that depend on a variety of factors. The processes by which accretionary wedges grow are well documented, however the processes by which accretionary wedges erode are more enigmatic. This project will examine the Pacific Coast of Costa Rica and evaluate the current rates and the total shortening associated with active thrust faults in the inner fore arc of the Middle America Trench-faults that allow subduction erosion through underthrusting of the outer fore arc. Results will be used to evaluate whether there has been an arcward shift in the location of rapid shortening from the toe to the interior of the wedge for this area of rough crust and shallow subduction. This work is expected to increase knowledge about how accretaionary wedges erode.