This study documents the occurrence of dinoflagellate cysts from the Middle Eocene Tallahatta and Lisbon Formations in the Baldwin County, Alabama, Core. This is part of a larger project being conducted by the ARCO Depositional Sequence Analysis Group to gather paleontological, sedimentological, paleomagnetic, geophysical, and geochemical data from the Alabama Coastal Plain for the purpose of calibrating the Tertiary time scale with the sequence stratigraphy of the Gulf region. A total of 101 taxa were identified, including 55 genera, 91 species, and 10 subspecies. Statistical analyses were run on the data collected to identify paleoecologic patterns and to relate these patterns, if possible, to sedimentary sequences. Diversity curves generated from the data show that there is usually a rise in diversity at sequence boundaries and at introsequence surfaces. Q-mode cluster analysis and detrended correspondence analysis indicate that samples tend to cluster within sequences. R-mode cluster analysis was performed and live informal cyst associations are discussed. Comparison of this studies assemblage with ranges published by Goodman and Stover (1975, 1983), and Edwards (1982) confirm the Middle Eocene age assigned to these units. / Master of Science

This study documents the vertical and lateral distribution of organic-walled phytoplankton cyst assemblages from samples taken from the Demopolis-Ripley transition interval, a pelagic carbonate to marine clastic facies transition in the Upper Cretaceous Selma Group of Mississippi and Alabama. The study samples have yielded abundant and diverse assemblages of dinoflagellate, chlorophyte, and acritarch cysts. In all, 70 species of organic-walled phytoplankton cysts are treated. On the basis of the ranges of the dinoflagellate cyst species recovered from the present study samples, the Demopolis-Ripley transition interval in the study sections is correlated with the lower Maastrichtian of western Europe. Also, on the basis of the data from the present study and other unpublished dinoflagellate cyst data, the Campanian-Maastrichtian boundary in the Selma Group is shown to lie at some point within the middle one-half of the Demopolis Chalk. The application of computer-based gradient analysis programs to a Recent dinoflagellate cyst dataset from the continental shelf of South Africa has shown that gradient analysis of organic-walled phytoplankton cyst assemblages can be useful in the recognition of patterns of marine watermass distribution. Finally, the application of gradient analysis techniques, including cluster analysis, polar ordination, mean rank abundance (MBA) analysis, and average member similarity (AMS) analysis, to the Demopolis-Ripley organic-walled phytoplankton cyst assemblages has allowed the recognition of four paleoecological significant phytoplankton cyst associations. The stratigraphic distributions of these associations correspond well to the changing distributions of watermass characteristics which are likely to have accompanied the Denopolis-Ripley facies transition. / Master of Science

Marine organic-walled microplankton biostratigraphy of the Maastrichian Prairie Bluff Chalk is documented. A total of 69 dinoflagellate species were identified in the Prairie Bluff Chalk. Samples were studied from three sites in central and western Alabama (Tombigbee River, Millers Ferry, and Braggs). Also included were several samples of the overlying Clayton Formation, and the underlying Ripley Formation. The species and their stratigraphic ranges were compared with other coeval sections in the U. S. and Europe. Dinoflagellate Zones Va and Vb of Wilson (1974) are recognized in the Prairie Bluff Chalk. This suggests the age of the Prairie Bluff Chalk is restricted to late Maastrichtian. The Prairie Bluff Chalk correlates to the upper Providence Formation of Georgia (Firth 1984); the lower Providence being early Maastrichtian. The basal Clayton Formation may be latest Maastrichtian in age / Master of Science