Integrated sequence stratigraphy of the Paleocene-Lowermost Eocene, New Jersey coastal plain: implications for eustatic and paleoceanographic change

This study uses a high-resolution integrated sequence stratigraphic method to determine the paleoecologic, paleoceanographic, and sea-level changes during the Paleocene-early Eocene. One of the more intriguing problems in paleoceanography is determining the cause of large sea-level changes of > 20 m in < 1 Myr during the "greenhouse" interval. The principal hypotheses presented here suggest a glacioeustatic mechanism for sea-level change during the Paleocene-earliest Eocene. A multidisciplinary approach was implemented utilizing sequence stratigraphic core description, carbon and oxygen isotope analysis, benthic foraminiferal biofacies, and biostratigraphy (nannofossils) to evaluate the magnitude of sea-level changes and possible eustatic mechanisms. The bulk of this study was conducted on the New Jersey coastal plain because of its well-known geologic history, excellent microfossil preservation, and well known sequence stratigraphic framework due to the drilling efforts of ODP Legs 150X and 174AX. The foundation of this study (Chapter 1) includes a detailed sequence stratigraphic analysis of Paleocene-lowermost Eocene sequences. This study identified seven Paleocene-lowermost Eocene sequences and corresponding paleodepths. Paleodepths were ~80 m during the early Paleocene, with a maximum water depth of 100 m at Bass River. A long-term shallowing of ~20 m is observed through the middle-late Paleocene toward the earliest Eocene. The shallowing trend reverses, with a water depth increase to ~120-150 m (Chapter 2). The New Jersey sequences correlate with those in other localities and δ18O increases in deep sea (Chapter 3), suggesting a glacioeustatic mechanism for sea-level change during the Paleocene-earliest Eocene. The New Jersey coastal plain also provides an excellent record of the Paleocene- Eocene Thermal Maximum (PETM) and Carbon Isotope Excursion (CIE). The PETM/CIE is distinguished by the occurrence of an unusual assemblage of coccolithophorids, referred to as the "RD". This study tested the first appearance of the RD in relation to a CIE precursor found in the New Jersey coastal plain and utilized paleodepths to construct one of the few sea-level records calibrated to the PETM and the mechanisms responsible for a 30-60 m eustatic rise during this interval.Ph.D.Includes abstractVitaIncludes bibliographical referencesby Ashley D. Harri