Thesis (Ph.D.) - James Cook University, 2004. / "Met een samenvatting in het Nederlands" -- T.p. "Ter verkrijging van der graad van doctor aan de Universiteit Utrecht, op gezang van de Rector Magnificus, Prof. Dr. W. H. Gispen, ingevolge het besluit van het College voor Promoties in het openbaar te verdedigen op donderdag 30 septembber 2004 des morgens om 10:30 uur" -- T.p. Typescript (photocopy) Bibliography: leaves 175-181.

Diverse, well preserved organic-walled phytoplankton assemblages were recovered from the Tertiary section of the Oak Grove core drilled on the Virginia Coastal Plain. Strata penetrated include the Aquia, Marlboro Clay, and Nanjemoy Formations (Paleocene to Eocene) of the Pamunkey Group and the Calvert and Choptank Formations (Miocene) of the Chesapeake Group. The assemblages are composed of 176 dinoflagellate species and subspecies (82 genera), of which 20 species and subspecies and one combination are new; five acritarch species (two genera) and five chlorophyte species (three genera) are also reported. The biostratigraphic distribution of the 186 species provides information concerning the ages of the formations and the nature of their lithologic contacts. The organic-walled phytoplankton assemblages corroborate the Paleocene (Thanetian) age indicated by the calcareous nannofossils, Foraminifera, ostracodes, and pollen and spores for the Aquia strata; certain dinoflagellate and pollen species in the lowermost 11.5 m (37.9 ft), however, suggest this basal interval, devoid of other microfossils, could be Paleocene (Danian) in age. An Eocene (Ypresian) age is assigned to the Nanjemoy strata based on the organic-walled phytoplankton, as well as the pollen and spores, calcareous nannofossils, ostracodes, and mollusks. The intervening Marlboro Clay appears to straddle the Paleocene-Eocene boundary based on its dinoflagellate and pollen species. Dinoflagellate species suggest a general Early to Middle Miocene age for the Calvert and Choptank section in the core; diatom samples in the Calvert indicate a late Early to early Middle Miocene age and in the Choptank a middle Middle Miocene age. Lithologic and biostratigraphic evidence suggests the upper and possibly the lower Marlboro Clay contacts represent minor disconformities, in addition to the major disconformity at the Nanjemoy-Calvert boundary; the Calvert-Choptank contact appears conformable. The ten provisional dinoflagellate zones proposed for the Aquia, Marlboro Clay, and Nanjemoy strata of the core permit correlation with other previously studied Paleocene and Eocene sections of the Virginia and Maryland Coastal Plain. These Lower Tertiary strata are also generally biostratigraphically correlated with numerous coeval European sections, and a composite offshore eastern Canada section. The dinoflagellate, acritarch, and chlorophyte assemblages are statistically analyzed for paleoenvironmental implications using species diversity indicators (richness, Shannon-Wiener index, evenness) and analyses patterned after previous palynological studies suggesting correlation of various assemblage parameters and characteristics with particular depositional environments. Results are consistent with sedimentological and foraminiferal-based paleoenvironmental assessments of generally inner shelf marine settings for the Aquia, Nanjemoy, Calvert, and Choptank Formations, and a lagoonal or estuarine setting for the Marlboro Clay. Cluster, principal coordinates, and rank-abundance analyses help to objectively define and characterize six major and 12 smaller clusters of samples related by their species associations through time. / Ph. D.

This study documents the occurrence of dinoflagellate, chlorophyte, and acritarch cysts from the Upper Cretaceous upper Cusseta, Ripley, and lower Providence Formations in the USGS Fort Gaines core, drilled in Clay County, Georgia. A total of 75 taxa were identified, consisting of 36 genera, 61 species, and 5 subspecies of dinoflagellates, 3 genera and 4 species of chlorophytes, 3 genera and 4 species of acritarchs, and 1 problematical protozoan. 15 of these taxa are unpublished. The study's cyst assemblage was statistically analyzed to ascertain paleoecologic patterns. The results from cluster analysis and detrended correspondence analysis indicate the presence of four cyst associations. The <i>Deflandrea pannucea</i> association is interpreted as indicative of low salinity related to nearby river discharge. The <i>Deflandrea</i> sp. A association is confined to the inner shelf. The <i>Exochosphaeridium bifidum</i> and <i>Glaphyrocysta reticulosa</i> associations alternate under normal marine conditions. The associations correlate well with observed lithologies and lithologic change. Comparison of this study's assemblage with other Late Cretaceous assemblages provides limited information, since many biostratigraphically-important species are not present in this study. However, comparisons with Wilson's (1974), Benson's (1976), and Firth's (1984) zonations suggest a Lower Maastrichtian age for all strata in this study. / M.S.

Thesis (Dr. rer. nat.)--Universität Tübingen, 2004. / Includes bibliographical references. Available in PDF format via the World Wide Web.