An Investigation of Deformational Processes in the Forearc Accretionary Complex of the Lesser Antilles Subduction Zone

在两个板块交汇的地方，从下行板块刮下来的沉积物堆积在岛弧上形成了一个吸积棱镜。从结构上讲，这种棱镜非常复杂，它们的演变还没有完全被理解。在之前的一个NSF资助的研究项目中，Ladd博士和他的同事利用两艘船使用现代和复杂的地震方法成功地对巴巴多斯增生楔进行了调查和成像。在这个奖项中，Ladd博士和他的同事们将继续对这些优秀的数据集进行地震解释，并将进行详细的分析，以获得有关增生棱镜中地震速度的更多信息。地震速度将提供有关棱柱的密度和孔隙度的信息，反过来，这些信息将揭示构成棱柱的沉积物的岩性以及增加棱柱内流体流动的方向。这些都是在增生棱镜的演化过程中的一些基本问题，回答这些问题将有助于我们理解板块构造过程。该项目将在87财年获得为期12个月的100,018美元资助。

An accretionary prism is formed in an island arc by the accumulation of sediments scraped off from the downgoing plate where two plates converge. Structurally, such prisms are very complex and their evolution is not fully understood. In a previously NSF funded research project, Dr. Ladd and his coworkers successfully surveyed and imaged the Barbados accretionary wedge by using modern and sophisticated seismic methods utilizing two ships. In this award, Dr. Ladd and his colleagues will continue seismic interpretation of this excellent data set and will perform detailed analysis to obtain more information about seismic velocities in the accretionary prism. The seismic velocities will provide information on density and porosity of the prism which, in turn, will reveal lithologies of the sediments composing the prism and the direction of the fluid flow within the accreted prism. These are some of the fundamental questions in the evolution of an accretionary prism and answering these questions will help us in understanding the plate tectonic processes. The project will be supported at $100,018 for 12 months in FY87.