Paleoceanography

Integrated stratigraphic studies of Paleocene–lowermost Eocene sequences, New Jersey Coastal Plain: Evidence for glacioeustatic control

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Abstract

[1] We describe seven Paleocene to lowermost Eocene sequences in core holes at Island Beach, Bass River, Ancora, Millville, and Sea Girt, NJ (Ocean Drilling Program Leg 150X, 174AX) and analyze benthic foraminiferal assemblages to assess paleodepth changes within sequences. These sequences are referred to as Pa0, Pa1a, Pa1b, Pa2a, Pa2b, Pa3a, and Pa3b. Paleocene sequence boundaries are identified by unconformities and variations in benthic foraminiferal biofacies. We used Q-mode factor analysis and paleoslope modeling to identify three distinct middle-outer neritic benthic foraminiferal assemblages and their associated water depths. Paleodepths during the early Paleocene and deposition of Pa0, Pa1a, and Pa2b were ∼80 m with ∼20 m changes across sequence boundaries. A long-term shallowing occurred through the late Paleocene where paleodepths were ∼50–70 m in Pa3a. This trend drastically changes in the earliest Eocene where the paleodepths of sequence Pa3b were ∼120–150 m. New Jersey Paleocene sequence boundaries correlate with those in other regions and with δ18O increases in the deep sea, suggesting Paleocene eustatic lowerings were associated with ice-growth events.

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