To better understand how the evolution of Cenozoic deep-water circulation related to changes in global climate and ocean basin configuration, we generated Nd isotope records from Ocean Drilling Program sites in the southeastern Atlantic to track deep water mass composition through time. We used fossil fish debris from ODP Sites 1262-1264 (Leg 208), spanning present-day water depths of 2500-4750 m, to reconstruct the isotopic signature of deep waters over the past ~53 Ma. The data indicate an initial transition from relatively non-radiogenic values (??Nd=~-10) at 53 Ma to more radiogenic values (~-8.5) at ~32 Ma. From ~32 Ma to 3.85 Ma, the Nd signal becomes more nonradiogenic, ~-12.3 at the top of the record. Comparison of our data with Nd isotopic records derived from a North Atlantic Fe-Mn crust show similar non-radiogenic values (~-10.5) in the 53??32 Ma interval and a trend toward more non-radiogenic values beginning at ~20 Ma. The data likely reflect an overall shift from a Southern Ocean deep water source to the ultimate incursion of deep waters from the North Atlantic. The non-radiogenic values at the base of the record reflect a Southern Ocean source of deep water. The shift toward more radiogenic values indicates an increased contribution of Pacific waters to the Southern Ocean source as the tectonic gateways changed after ~35-33 Ma. The subsequent trend toward more non-radiogenic Nd isotope values is approximately concurrent with the increase of benthic foraminiferal ??18O values, based on comparison with a compilation of global data. Thus, changes in oceanic gateway configuration in addition to overall cooling and the build-up of continental ice on Antarctica may have altered the Nd isotope character of Southern Ocean deep waters during the early Oligocene.

Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1988. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 87-92).

Thesis (Ph. D.)--Massachusetts Institute of Technology. / Funded by the National Science Foundation, grant number OCE 84-15720 and by the Andrew A. Mellon Foundation. Includes bibliographical references.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2006. / Bibliography: leaves 162-184. Also available online.

The Black Sea becomes periodically isolated from the global ocean during each glacial period. This occurs when the elevation of the global ocean is lower than the Bosporus sill, putting a stop to inflow of salt water to the Black Sea. This phenomenon allows the Black Sea to evolve from a marine environment to a freshwater one. It is also evident that the depth of the Bosporus sill does not remain at the same elevation, and instead is dynamic. The sill becomes filled with sediments during periods of its sub-aerial exposure but is subsequently eroded to its bedrock during periods of outflow from the Black Sea-Lake to the global ocean. This interpretation comes from the observations that during the last glacial period, the Black Sea-Lake was in a positive hydrological balance, fresh, and predominantly outflowing to the global ocean over a deep Bosporus sill, at approximately 80 meters below sea level (mbsl). It is highly likely that there were brief periods when the lake froze and the outflow suspended, such as during the extreme stadial conditions associated with the North Atlantic iceberg-discharge Heinrich Event 2 (HE 2) at ~24 kyr before present, when there is also no evident carbonate accumulation in stalagmites that receive water from evaporated Black Sea surface water. Upon the onset of deglaciation, large floods originating from the Fennoscandinavian Ice Sheet and the Alps, delivered meltwater so as to fully ventilate the Black Sea-Lake and even potentially replace all of the water in the basin. These floods occurred near the time of the deglacial iceberg-discharge Heinrich Event 1 (HE 1 at ~17 kyr before present), and left pulses of red-colored sediment everywhere on the western half of the Black Sea basin.

The Upper Albian (mid-Cretaceous) sediments of the Anglo-Paris Basin display a range of condensation phenomena, including glauconitic and phosphoritic sands, glauconitic intraformational pebble beds, and mineralised nodular hardgrounds. These are interpreted as the result of sedimentation rate fluctuations controlled by small-scale relative sea-level changes of at least regional nature. The regional signal was modified by local tectonics, including occasional synsedimentary faulting and the development of thinned successions and complex condensation horizons over broad submarine highs. Candidate sequence boundaries, marine flooding surfaces and systems tracts are proposed. Episodic, high-energy storm events record a spectrum of storm intensities and periodicities in the Upper Greensand Formation. Storm processes interacted with early submarine lithification to produce a suite of pebble-shell beds, simple and amalgamated coquinas, and storm-scoured hardgrounds. Analysis of shell bed fabrics and taphonomy indicates the important role of high-energy storms in generating a distinct event stratigraphy. Stable isotope analysis has detected a positive secular change in carbon-isotopic ratios within carbonates of dispar zone age, resolved as two smaller positive shifts across nodular hardgrounds. This correlates with the development of organic-rich sediments in a range of settings world-wide. Analytical problems, including silica diagenesis, have been addressed by a series of parallel control studies. Geochemical and petrographic analysis has confirmed the widespread development of glauconitic minerals throughout the Upper Greensand, and has been used to investigate grain evolution in a range of lithologies. A review of the global development of the Cretaceous glauconitic facies has been used to compile depositional models for a range of settings. Volumetric calculations of Cretaceous glauconite production rates have shown secular changes, with peak Aptian to Santonian values linked to transgressions across the broad shelf seas which developed globally during this time of rising sea-levels and sea-level highstand.

Thesis (Ph.D.)--Australian National University, 2004. / CD contains thesis in pdf and data files. Text organised differently in printed version.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 74-79). Also available on the World Wide Web.

Thesis (Ph. D.)--Harvard University, 1987. / Includes bibliographical references.