The Fine-scale Hydrology and Geochemistry of the Areas of Active Venting Middle Valley, a Sedimented Rift on the Northern Juan de Fuca Ridge

Langseth 9417011 这项研究计划由来自印第安纳大学、杜克大学和哥伦比亚大学的研究人员参与，旨在详细研究胡安德富卡海岭活跃温泉附近沉积物丰富的环境中热液循环的过程，胡安德富卡海脊是位于俄勒冈州、华盛顿州和加拿大西部附近的大洋中脊扩张中心。 为为期一个月的实地工作提出的具体计划包括对沉积部分内的热、化学和流体传输以及这些沉积物的物理性质的研究。 获取这个详细的多成分数据集的目的是使用这三个相互依赖的成分来约束和定义流体路径和化学反应的模型，包括热喷口上方的泥浆和岩石内硫化物矿物的沉积。 详细的计划之所以成为可能，部分原因是它使用了最先进的热流和孔隙水测量技术，这组研究人员在促进和应用这些技术方面发挥了重要作用。 先前在这两个拟议地点进行的研究包括由 NSF 赞助的海洋钻探计划船 JOIDES Resolution 进行的钻探，新数据允许对面积结果（利用沉积物上部 20 米的新测量值）和深度结果（利用现有钻探数据和计划的未来钻探数据，预计在 1996-97 年时间范围内）进行推断，以定义循环和矿化的 3 维结构。 除了首次对已知可产生大量矿化矿床的沉积温泉进行如此详细的研究外，该计划还将为精确选择未来钻探地点提供有价值的数据。

Langseth 9417011 This research program, involving researchers from Indiana, Duke and Columbia Universities, proposes to investigate in detail the processes involved in circulation of hydrothermal fluids in a heavily sedimented setting adjacent to active hot springs on Juan de Fuca Ridge, a mid-ocean ridge spreading center located off Oregon, Washington and western Canada. The specific programs proposed for the one-month field effort include studies of heat, chemical and fluid transport within the sedimentary section and the physical properties of those sediments. The objective in acquiring this detailed, multicomponent data set is to use these three interdependent components to constrain and define models of the fluid pathways and chemical reactions, including the deposition of sulfide minerals within the mud and rock overlying the thermal vents. The detailed program is possible in part because it uses cutting edge technology for heat flow and pore water measurement, which this group of investigators has been instrumental in fostering and bringing to use. Previous study at the two proposed sites includes drilling by the NSF-sponsored Ocean Drilling Program vessel JOIDES Resolution, and the new data allows extrapolation of results both areally (with new measurements from the upper 20 meters of the sediments) and with depth (with existing drilling data and planned future drill data, which is expected in the 1996- 97 time frame) to define the 3-dimensional architecture of circulation and mineralization. In addition to providing the first study at this level of detail over sedimented hot springs known to produce large mineralized deposits, the program will provide valuable data for precise selection of sites for future drilling.