n-Alkane, fatty acid and hopanoic acid concentrations of ODP Site 190-1178 samples

Ocean Drilling Program (ODP) Leg 190 was programmed to investigate deformational, diagenetic, and hydrologic processes and their interactions in the Nankai Trough accretionary prism. Site 1178 is the northernmost site in the Muroto Transect. Slope sediments and the underlying landward-dipping reflector zone were successfully cored. Temperature measurements and Cl concentrations in pore water indirectly indicate the presence of gas hydrate between 120 and 400 meters below seafloor (mbsf) at Site 1178, with the highest concentrations between 150 and 200 mbsf (Shipboard Scientific Party, 2001, doi:10.2973/odp.proc.ir.190.109.2001). Sedimentary structures show a broad range of deformation structures rich in fractures, suggesting active fluid circulation in the Nankai Trough prism. […]

大洋钻探计划（Ocean Drilling Program, ODP）第190航次的科学目标为探究南海海槽（Nankai Trough）增生楔（accretionary prism）内的变形、成岩及水文过程及其相互作用。1178站位是室户断面（Muroto Transect）的最北端站位，该站位成功获取了斜坡沉积物及其下伏向陆倾反射带的岩芯。通过温度测量与孔隙水氯离子浓度分析，间接证实1178站位在海底以下120~400米（meters below seafloor, mbsf）范围内存在天然气水合物，其浓度峰值出现在150~200 mbsf区间（船上科学工作组，2001，doi:10.2973/odp.proc.ir.190.109.2001）。沉积构造显示存在大量以裂缝发育为特征的变形构造，表明南海海槽增生楔内存在活跃的流体循环活动。[…]