Collaborative Research: Integrated Eocene-Oligocene Stratigraphy of Alabama and Mississippi Boreholes: Comparison with the NJ Transect and Global Sea-Level Proxies

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9506451 Kent The processes of global sea-level, local tectonics, and changes in sediment supply control passive continental margin sedimentation. Determining the role of each requires continuous sampling and dating of stratigraphic sections in different tectonic settings. Global sea level studies are a fundamental component of global change programs and sea level studies require drilling transects of boreholes on passive continental margins. These transects will first focus on the Oligocene-Recent "Icehouse" with future drilling to address sea-level changes during the Paleocene- Eocene "Greenhouse" and "Doubthouse" when ice-volume changes were not apparent. The principal investigators are currently developing, with NSF funding, a firm chronology of New Jersey coastal plain Eocene to middle Miocene sequences, but require well- dated sections on other passive margins to evaluate the role of eustatic versus local effects. Previous and ongoing studies show that continuous cores from western Alabama and eastern Mississippi provide fresh, unweathered material from the middle Eocene to the "middle" Oligocene. The principal investigators will conduct integrated magneto-, bio-, and isotopic (Sr, oxygen, and carbon) studies of three recently drilled boreholes in Mississippi. Preliminary results funded by ARCO show that these boreholes contain expanded upper Eocene to lower Oligocene sections suitable for magneto-, bio-, and Sr-isotope studies. These sections should compare well with the principal investigator's ongoing studies in New Jersey. The Alabama and Mississippi studies will provide an "Icehouse" transect of the Oligocene to compare with sequences in New Jersey and other proxies of global sea-level change and a detailed transect of the "Greenhouse" early Eocene and "Doubthouse" middle-late Eocene. ***