Generation of Overpressures, Fluid Migration, Mass Transport and Diagenesis Associated with Deformation and Dissolution of Allochthonous Salt Sheets in the Deep Water Gulf of Mx..

墨西哥湾沉积盆地盐体的大规模垂向和横向运移对这部分地壳的地层、构造和水文地质演化起到了重要作用。我们建议将之前在较老的陆上沉积物中所做的工作扩展到深水湾，那里活跃的盐变形、流体流动以及热和溶质运移使其成为检验流体流动、质量转移、成岩作用和构造过程耦合假说的理想区域。我们将在数十公里的微型盆地尺度上开展为期三年的流体流动和化学反应研究。数值模拟将用于研究超压和压实驱动流的产生、密度驱动和压实驱动的耦合流动、韧性剪切带内的超压和幕式流体流动以及微盆地尺度上对盐溶和孔隙水矿化度的物理控制。这项工作将整合野外记录的地层水和沉积物性质的空间变化，这些变化来自于电缆测井和对盐度差异很大的系统中沉积物-流体成岩反应的计算。虽然我们的研究将集中在墨西哥湾盆地，但结果将广泛适用于任何含盐沉积盆地。对这一目前活跃的盆地的研究将为目前构造不活跃或已被主要构造过程破坏的盆地的演化提供重要线索。

9805459NunnLarge-scale vertical and lateral migration of salt bodies in the Gulf of Mexico sedimentary basin has played an important role in the stratigraphic, structural, and hydrogeologic evolution of this portion of the earth's crust. We propose to extend our previous work in older onshore sediments out into the deep water Gulf, where active salt deformation, fluid flow, and heat and solute transport makes it an ideal area to test hypotheses regarding coupling between fluid flow, mass transfer, diagenesis, and tectonic processes.We will carry out a three-year study of fluid flow and chemical reaction on the tens of kilometer minibasin scale. Numerical modeling will be used to investigate the generation of overpressure and compaction-driven flow, coupled density-driven and compaction driven flow, over pressuring and episodic fluid flow within ductile shearing zones, and physical controls on salt dissolution and pore water salinity on the minibasin scale. Integrated into this work will be field-documented spatial variations in formation water and sediment properties derived from wireline logs and calculations of sediment-fluid diagenetic reactions in systems of widely varying salinity.While our studies will be focused on the Gulf Basin, the results will be broadly applicable to any sedimentary basin containing salt. Study of this currently active basin will provide important clues to the evolution of basins now tectonically inactive or which have been largely destroyed through major tectonic processes.