Hydrous Phases in Subduction Zone Settings: Effects on Sediment Physical Properties and Microfabric

沉积物埋藏过程中伴随的脱水和压实过程受沉积物成分和微组构(即颗粒与颗粒的相互作用)的强烈影响。为了更好地了解俯冲带环境中的流体流动、沉积、底侵和断层作用，需要改进对这两个过程的记录。特里布尔和威尔肯斯博士将扩展巴巴多斯吸积棱镜的早期工作，以包括对南开海槽的ddp/dpp岩心的研究。将使用X射线衍射来确定几个地点的样品的矿物学，以形成统一存档的数据集。将特别强调确定蒙皂石和生物硅的丰度和成岩蚀变作用。火山灰向蒙皂石的逐渐蚀变将被追踪到。微结构研究将通过扫描和透射电子显微镜进行，目的是量化结构随深度、组成和构造环境的变化。

The companion processes of dewatering and compaction that occur during sediment burial are strongly influenced by sediment composition and micro-fabric (i.e., grain-to-grain interactions). Improved documentation of these two processes is needed to gain better understanding of fluid flow, accretion, underplating and faulting in subduction zone settings. Drs. Tribble and Wilkens will extend earlier work from the Barbados accretionary prism to include studies of DSDP/ODP cores from Nankai Trough. X-ray diffraction will be used to determine the mineralogy of samples at several locations to develop a uniformly archived data set. Special emphasis will be placed on determining the abundances and diagenetic alteration of smectite and biogenic silica. Progressive alteration of volcanic ash to smectite will be traced. Microfabric studies will be conducted with both scanning and transmission electron microscopy, with the intention of quantifying changes in fabric with depth, composition and tectonic setting.