Barbados Accretionary Prism Hydrogeologic Characteristics: Submersible-Based Tests at ODP Sealed Boreholes

卡森9415924该项目由利哈伊大学的Bobb Carson博士领导，有来自印第安纳大学、加州大学圣迭戈分校斯克里普斯海洋研究所和法国海洋研究实验室IFREMER的研究人员参与。这项研究遵循海洋钻探计划第156段，该计划的主要目标是评估巴巴多斯吸积棱柱滑脱(深埋在沉积楔形中的流体通道)沿线的水文地质条件。在JOIDES RESOLUTION的钻探计划期间，在两个钻探地点安放了带有温度和化学采样系统的密封钻孔(“软木塞”)，以隔离跨滑脱层的区段，从而使未来能够对假设孔隙水沿其迁移的这一地平线进行研究。本项目将于1995年夏天，即钻探后大约一年，在两个钻孔地点之一进行水文地质研究和用于地球化学研究的孔隙水采样；法国研究人员将在第二个地点的同一实地方案中进行类似的实验。现场项目将在法国研究潜水器诺蒂尔号上进行。该研究计划旨在确定原地水文地质特征和条件，为下一代吸积棱柱流体流动模型提供真实的参数。这项研究以及放置外壳和采样沉积物的大洋钻探支路的总体目标是了解俯冲过程中沉积物转化过程的性质，以及流体的运输如何影响沉积物和海洋的化学。巴巴多斯地区是世界上研究得最好的吸积棱柱之一，它为在板块构造背景下研究沉积物的俯冲、变形和岩化作用提供了一个天然实验室。了解板块俯冲所涉及的过程是Oce An钻井计划的高度优先事项。***

Carson 9415924 This program, led by Dr. Bobb Carson of Lehigh University, involves researchers from Indiana University, from Scripps Institution of Oceanography at the University of California, San Diego, and from the French marine research laboratory IFREMER. The study follows Ocean Drilling Program Leg 156, whose primary goal was to assess the hydrogeologic conditions along the decollement (a fluid pathway deeply buried in the sedimentary wedge) of the Barbados accretionary prism. During that drilling program on JOIDES Resolution, sealed boreholes ("CORKs") with temperature and chemical sampling systems were emplaced at two drill sites to isolate the section across the decollement, allowing future study of this horizon along which pore waters are hypothesized to migrate. The present project will carry out hydrogeologic studies and pore water sampling for geochemical study in the summer of 1995, approximately one year after drilling, at one of the two borehole sites; French researchers will conduct similar experiments during the same field program at the second site. The field program will be carried out on the French research submersible Nautile. The research program seeks to determine in situ hydrogeologic characteristics and conditions that will provide realistic parameters to the next generation of fluid flow models for accretionary prisms. The overall objective of this research, as well as that of the ocean drilling leg which emplaced the casings and sampled the sediments, is to understand the nature of the processes by which sediments are transformed in the process of subduction, and how the transport of fluids affects the chemistry of the sediments and the ocean. The Barbados region is one of the best studied accretionary prisms in the world, and it provides a natural laboratory for the investigation of subduction, deformation and lithification of sediments in the context of plate tectonics. Understanding the processes involved in plate subduction is a high priority of the Oce an Drilling Program. ***