by Gregory S. Mountain, Kenneth G. Miller, Nicholas Christie-Blick, Peter J. Sugarman, Peter J. Sugarman, Craig S. Fulthorpe

The NJ Coastal Plain and continental shelf/slope comprise a "natural laboratory" for unraveling eustasy and margin sedimentation by exploiting the chance to drill a series of linked boreholes as part of the ‘NJ/Mid-Atlantic Transect’ (NJ/MAT). Consequently, this margin has been the focus of previous drilling both onshore and offshore (ODP Legs 150X, 174AX, 150 and 174A, respectively). Each of these efforts has successfully dated sequence boundaries and tied them to the d18O proxy of glacioeustasy, but all have fallen short of the ultimate objectives for either of two reasons: 1) the region most sensitive to sea-level change, the inner shelf, has not been sampled; and 2) drilling technology aboard the ODP drilling platform, JOIDES Resolution, is not well suited for recovering sandprone continental shelf sediments. Consequently, a critical gap remains in the NJ/MAT and our knowledge of global sea-level change. The drilling we propose is designed to obtain deep sub-seafloor samples and downhole logging measurements in this crucial inner shelf region using a mission-specific platform. MAT 1-3 represent the most sensitive and accessible locations for bringing the New Jersey Transect to a successful conclusion. In 1999, ICDP committed a $500,000 contribution towards drilling this transect; we are now poised to conduct the transect as a joint IODP-ICDP effort, though ICDP has asked the PI’s to submit a revised proposal considering the time since the previous commitment. The role of ICDP is critical in this joint endeavor. The cost of drilling and logging all 3 sites is in the range of $6 M to $8 M, and as such, the ICDP’s contribution is pivotal. Equally important, collaboration of ICDP and IODP will demonstrate that fundamental scientific interests are shared by these leading organizations and will make great strides towards a more unified approach in using drilling to answer basic questions about Earth processes.

• The inner to middle shelf offshore New Jersey is an ideal location to investigate the history of sea-level change and its relationship to sequence stratigraphy for several reasons: rapid depositional rates, tectonic stability, and well-preserved, cosmopolitan fossils suitable for age control characterize the sediments of this margin throughout the time interval of interest. Coring and logging along a depth transect at 3 sites embedded within a regional seismic grid and correlated to previously drilled holes both offshore and onshore will allow us to:
• 1) date major "Icehouse" (Oligocene-Recent) sequences, a time of known glacioeustatic change, and compare ages of the unconformable surfaces bracketing these sequences with ages of sea-level lowerings predicted by the d18O glacioeustatic proxy;
• 2) estimate the amplitudes, rates, and mechanisms of sea-level change; and 3) evaluate sequence stratigraphic facies models that predict depositional environments, sediment compositions, and stratal geometries in response to sea-level changes.

Climate Change, Continental Margin, Deep Biosphere, Drilling, Eustasy, Global Environment, ICDP-2006/04, New Jersey, NJCP, NJSS, Shallow Shelf, U.s. East Coast, U.s.a.

Latitude: 39.6341, Longitude: -73.62168