Stratigraphic Framework for Mapping Potential Mineral and Ground Water Resources, Coastal Mississippi; Groundwork for New Coastal Map, Phase 1.
In coastal Mississippi we face questions in two major, interconnected geological areas. The answers would greatly facilitate the search for mineral and ground water resources of this region. All the upper miocene-pliocene(?) age artesian ground water horizons occur in the stratigraphic interval studied, and the middle miocene natural gas resources and gas shows of southwest Alabama and southeast Mississippi also occur in that interval. Owing to the abundance of fossil-free terrestrial and reduced-salinity neogene units in the updip subsurface and the scarcity of studies of the marine units downdip, the presently generally accepted neogene stratigraphic picture in this area is riddled with problems and contradictions. In addition, the stratigraphy of the younger, pleistocene deposits and their sediment content is also poorly known on the coast. There is a great need for an up-to-date regional geological map. Our purpose in this segment of our stratigraphic research was thus twofold. First, with the use of microfossil data from drill-core samples taken in mainland coastal and offshore areas, as well as the adjacent south Alabama zone, great strides were made toward clarifying the neogene stratigraphy of the coastal zone. As part of the present investigations, we have exerted special effort to obtain drill samples and fossil data from two offshore drill holes (sapphire exploration/Mississippi sound block 90 and chevron block 57 exploration wells), as well as from the north Harrison County Mobil oil exploration well (by "well-sitting") in 1990. While the analysis of al