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

这个研究项目包括来自印第安纳大学、杜克大学和哥伦比亚大学的研究人员，他们建议详细调查在胡安·德·富卡山脊活跃温泉附近的一个重沉积环境中热液循环的过程。胡安·德·富卡山脊是位于俄勒冈州、华盛顿州和加拿大西部的海洋中山脊扩展中心。为为期一个月的实地工作提出的具体方案包括研究沉积剖面内的热量、化学和流体输送以及这些沉积物的物理性质。获取这些详细的多组分数据集的目的是利用这三个相互依赖的组分来约束和定义流体路径和化学反应的模型，包括热喷口上的泥浆和岩石中硫化物矿物的沉积。详细的程序之所以成为可能，部分原因是它使用了热流和孔隙水测量的尖端技术，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。之前在两个提议的地点进行的研究包括由美国国家科学基金会资助的海洋钻探计划船只JOIDES Resolution进行钻探，新的数据允许对结果进行外推（从沉积物上部20米处进行新的测量）和深度（利用现有钻探数据和计划中的未来钻探数据，预计在1996- 1997年期间），以定义循环和矿化的三维结构。除了提供对已知产生大型矿化矿床的沉积温泉进行如此详细的研究之外，该计划还将为未来钻探的精确选择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.