Abstract:
The shoreline is one of the planet's most fundamental divides and its movements are of great societal concern. However, funding agencies have historically split at this divide, with sea-level studies falling into programatic cracks. The NSF Continental Dynamics Program (CD) and International Continental Drilling Program (ICDP) have combined efforts with the Ocean Drilling Program (ODP), its successor the Integrated Ocean Drilling Program (IODP), and NSF ODP Program to fund a long-term mission on the New Jersey passive margin that unifies onshore drilling and offshore drilling. Seismic stratigraphic studies began in 1990 across the shelf (Ew9009), followed by detailed seismic grids on the outer (Oc270,1996) and inner shelf (CH0698, 1998). Onshore drilling began as ODP Leg 150X (1993-1994; Island Beach, Atlantic City, and Cape May), linked to Leg 150 on the NJ continental slope. Cooperative drilling continued with NJ outer shelf and slope drilling on Leg 174X in 1997, tied to onshore drilling as ODP Leg 174AX in 1996-2004 (Bass River, Ancora, Ocean View, Bethany Beach [DE], Fort Mott, Millville, Sea Girt, and Cape May Zoo), providing an unprecedented view of Upper Cretaceous to Miocene sequences. Sequences were dated with bio- and Sr-isotopic stratigraphy and lithofacies and biofacies were used to reconstruct paleowater depths. Oligocene-middle Miocene (ca. 33-10 Ma) sequence boundaries correlate onshore and offshore and with global oxygen isotope increases, linking them with glacioeustasy. Backstripping of the coreholes, progressively accounting for compaction, loading, and simple thermal subsidence, yields a history of 14-18 Late Cretaceous and 33 Cenozoic sea-level fluctuations of 30-50 m and provides a testable eustatic model. Magnitudes may be underestimated at these updip, onshore locations because lowstand deposits are generally absent and the sections are discontinuous (only approximately 66% of the past 100 m.y. represented). IODP/ICDP Expedition 313 will drill 3 sites in 2007 45-65 km offshore New Jersey where the Miocene strata are more complete. Expedition 313 will test facies models for prograding siliciclastic sequences and provide material for two-dimensional backstripping of Miocene sequences, and a eustatic estimate that captures the full amplitude of eustatic change.