Abstract:
During Integrated Ocean Drilling Program Expedition 313, proposed Sites MAT-1, MAT-2, and MAT-3 will be drilled on the New Jersey shallow shelf to 1. Date Paleogene-Neogene sequences and compare ages of the unconformable surfaces bracketing these sequences with times of sea level lowerings predicted from the delta (super 18) O glacio-eustatic proxy; 2. Estimate the corresponding 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 change. The New Jersey Coastal Plain and continental shelf/slope are a "natural laboratory" for unraveling eustasy and margin sedimentation by providing the chance to drill a series of linked boreholes as part of the "New Jersey/Mid-Atlantic Transect" (NJ/MAT). This margin has been the focus of previous drilling both onshore and offshore (Ocean Drilling Program [ODP] Legs 150X, 174AX, 150, and 174A). Each of these efforts has successfully dated sequence boundaries and tied them to the delta (super 18) O of glacioeustasy, but all have fallen short of the ultimate objectives because the region most sensitive to sea level change (the shallow shelf) has not been sampled and the technology aboard the ODP drilling platform (the R/V JOIDES Resolution) had not been well suited for recovering sand-prone shelf sediments. Consequently, a critical gap remains in the NJ/MAT that limits our knowledge of global sea level change and its imprint in the geologic record. The drilling we propose will use a mission-specific platform to obtain subseafloor samples and downhole logging measurements in this crucial shallow shelf region. Sites MAT-1 to MAT-3 represent the most sensitive and accessible locations for bringing the NJ/MAT to a successful conclusion.