Cooperative NSF-USGS Drilling in the Delmarva Peninsula: The Effects of Variations in Global Sea-Level Tectonic Subsidence, and Sediment Supply on Sequence Architecture

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EAR-9909179MillerSuccessful drilling onshore in the New Jersey Coastal Plain and offshore on the NJ shelf and slope has provided: 1) ages for major Late Cretaceous - Cenozoic sequence boundaries; 2) causal links between the formation of sequence boundaries and the growth of ice sheets between 42 and 10 Ma, and hints that such a link exists in the older, supposedly "ice-free" world; 3) preliminary estimates of the amplitudes of global sea - level changes; 4) evaluation of links among sequence stratigraphic architecture, global sea-level variations, and margin evolution; and 5) constraints on the causes of major global events in Earth history, including the middle Eocene-earliest Oligocene global cooling, the late Paleocene thermal maximum, the K/T boundary, early and late Maastrichtian events, and the Cenomanian/Turonian carbon extraction event. Drilling onshore in New Jersey has met fundamental goals, but has also raised fundamental questions that can be answered by drilling in the Delmarva peninsula. Drilling near Bethany Beach, DE will provide: 1) the first detailed record of upper Miocene-Pliocene (10 - 2) Ma sequences in this region; 2) downdip late Eocene to Pliocene sequences needed for eustatic estimates; 3) a stratigraphic reference section for the late Eocene Chesapeake Bay impact. This project will take advantage of an opportunity for joint funding and collaboration with the USGS by drilling a borehole on the coast near Bethany Beach, DE that will not only yield a late Eocene-Pliocene record of marine sequences, but also will provide a critical test of tectonic changes in subsidence on the Atlantic margin. The USGS Eastern Regional Mapping Team (ERMT) drillers will continuously core a 1500-1600 ft. borehole as part of a developing cooperative project with Rutgers, NSF, and allied partners (New Jersey Geological Survey, LDEO, USGS Water Resources, CNRS (France), WHOI, Delaware and Maryland Geological Surveys). Most direct drilling costs are already secured (USGS/NJGS/DGS); this award only provides science support costs and minimal drilling costs to deepen the hole for the P.I.s purposes. ***