Three Dimensional Paleohydrogeology of the Midcontinent, USA

美国大陆中部的沉积盆地含有大量的石油储层和铅、锌、重晶石和萤石矿床，其起源似乎与100公里以上的深层地下水和碳氢化合物的迁移有关。这些沉积盆地的地质和地球化学数据丰富，因此它们几乎是约束地下水流动和石油在地质时间和距离上迁移的理论模型的完美候选者。将建立一个新的三维有限元模型来量化深部地下水流量和热输运随时间的变化。然后，该模型将应用于两个特定区域问题的研究：(1)密苏里州东南部Ozark Dome的矿石形成；(2)俄克拉荷马州和堪萨斯州Anadarko盆地的石油运移。在区域尺度上，三维流动和输运对成矿的影响也将通过密苏里州东南部的Viburnum趋势和Old Lead带的详细模型进行研究。用与地下水流动系统相耦合的反应路径计算来检验矿溶输运和沉积的地球化学理论。这项工作代表了在盆地尺度上描述地下水平流的真正三维效应的第一次努力，因此它应该开拓地下水在地质过程中作用研究的新一代思想和应用。

Sedimentary basins of the United States Midcontinent contain significant petroleum reservoirs and ore deposits of lead, zinc, barite, and fluorite which appear to have origins related to the migration of deep groundwater and hydrocarbons over 100's of kilometers. Geological and geochemical data are abundant for these sedimentary basins and so they are nearly perfect candidates for constraining theoretical models for deep groundwater flow and petroleum migration over geological time and distances. A new three-dimensional finite-element model will be constructed to quantify coupled deep groundwater flow and heat transport as a function of time. This model will then be applied to studies of two specific regional problems: (1) Ore formation on the Ozark Dome of southeast Missouri and (2) Oil migration in the Anadarko Basin of Oklahoma and Kansas. The effects of three-dimensional flow and transport on ore formation a t the district-scale will also be investigated with detailed models of the Viburnum Trend and Old Lead Belt in southeast Missouri. Geochemical theories for ore- solution transport and deposition will be tested with reaction-path calculations which are coupled to the groundwater flow system. The work represents the first effort in characterizing true three- dimensional effects of groundwater plaeoflow at the basin scale and as such it ought to pioneer a new generation of ideas and applications in studies of the role of groundwater in geologic processes.