The Bass River Site was the fourth borehole drilled as part of the New Jersey Coastal Plain Drilling Project, which began with Ocean Drilling Program (ODP) Leg 150X drilling at Island Beach, Atlantic City, and Cape May (Miller et al., 1994a, 1994b, 1996). Bass River was drilled by the New Jersey Geological Survey (NJGS) and Rutgers University and is the first site drilled as part of ODP Leg 174AX, complementing shelf drilling by Leg 174A; future Leg 174AX drilling is planned for 1998 near Corson’s Inlet and Ancora, NJ. Fund for Bass River was provided by the NJGS for direct drilling expens and the National Science Foundation (Earth Sciences Division, C tinental Dynamics Program and Ocean Science Division, ODP) science support. Drilling at Bass River targeted middle Miocene and older s quences, with the primary focus on Upper Cretaceous (Cenoman Maastrichtian) to Paleocene strata that previously were poorly sa

Firm stratigraphic correlations are needed to evaluate the global significance of unconformity bounded units (sequences). We correlate the well-developed uppermost Campanian and Maestrichtian sequences of the New Jersey Coastal Plain to the geomagnetic polarity time scale (GPTS) by integrating Sr-isotopic stratigraphy and biostratigraphy. To do this, we developed a Maestrichtian (ca. 73-65 Ma) Sr-isotopic reference section at Deep Sea Drilling Project Hole 525A in the southeastern Atlantic Ocean. Maestrichtian strata can then be dated by measuring their Sr-87/Sr-86 composition, calibrating to the GPTS of S. C. Cande and D. V. Kent (1993, personal commun.), and using the equation Age (Ma) = 37 326.894 - 52 639.89 (Sr-87/Sr-86). Sr-stratigraphic resolution for the Maestrichtian is estimated as +/-1.2 to +/-2 m.y.At least two unconformity-bounded units comprise the uppermost Campanian to Maestrichtian strata in New Jersey. The lower one, the Marshalltown sequence, is assigned to calcareous nannofossil Zones CC20/21 (approximatelyNC19) and CC22b (approximatelyNC20). It ranges in age from approximately74.1 to 69.9 Ma based on Sr-isotope age estimates. The overlying Navesink sequence is assigned to calcareous nannoplankton Zones CC25-26 (approximately NC21-23); it ranges in age from 69.3 to 65 Ma based on Sr-isotope age estimates. The upper part of this sequence, the Tinton Formation, has no calcareous planktonic control; Sr-isotopes provide an age estimate of 66 +/- 1.2 Ma (latest Maestrichtian).Sequence boundaries at the base and the top of the Marshalltown sequence match boundaries elsewhere in the Atlantic Coastal Plain (Owens and Gohn, 1985) and the inferred global sea-level record of Haq et al. (1987); they support eustatic changes as the mechanism controlling depositional history of this sequence. However, the latest Maestrichtian record in New Jersey does not agree with Haq et al. (1987); we attribute this to correlation and time-scale differences near the Cretaceous/Paleogene boundary. High sedimentation rates in the latest Maestrichtian of New Jersey (Shrewsbury Member of the Red Bank Formation and the Tinton Formation) suggest tectonic uplift and/or rapid progradation during deposition of the highstand systems tract.

The Island Beach borehole was the first site drilled as part of the New Jersey coastal plain drilling project, Leg 150X.Located directly updip of the proposed offshore shelf sites (MAT 1-3) and the Ewing multichannel seismic (MCS) grid, this site focused on lower Miocene-Oligocene ("Icehouse"), middle-upper Eocene ("Doubthouse"), and Paleocene-lower Eocene ("Greenhouse") sequences.The upper Pleistocene-Holocene Cape May Formation at Island Beach records a generally deepening upward succession of fluvial, bay-estuarine-inner neritic, to nearshore facies that represents at least the Holocene transgression and perhaps additional sea-level cycles.Recovery of the 427-ft Miocene Kirkwood Formation was excellent, and the facies represent diverse fluvial, nearshore, and inner neritic (including prodelta) environments.Diatoms indicate correlation of the Kirkwood Formation at Island Beach primarily to East Coast Diatom Zone (ECDZ) 2 and older (lowermost middle to lower Miocene), whereas Sr-isotope stratigraphy dates the lowermost Kirkwood sequence recovered here as 21.8 Ma (early Miocene).Other biostratigraphic and isotopic correlations are lacking for the Kirkwood Formation at Island Beach because of shallow-water and nonmarine facies; however, the lithostratigraphic subdivisions of the Kirkwood Formation can be correlated to the Atlantic City borehole where they are dated using Sr-isotopic stratigraphy.These correlations allow the evauation of facies changes in at least four Miocene sequences tied to a time stratigraphic framework.Although the well-recovered Paleogene succession at Island Beach contains most nannofossil (NP3, NP5, NP6, NP9 through NP22, NP24-NP25), and planktonic foraminifer (Pic through P21a) zones, the section contains at least 10 disconformities.A 196-ft Oligocene section has unconformities at its top (505 ft, hiatus from 24.3 to 21.8 Ma based on Sr-isotope stratigraphy), middle (?602 ft, Zones P20-