Collaborative Research: NSF-NJGS Drilling of the Greenhouse World: The Cretaceous Transect

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0307112MillerSuccessful drilling onshore in the New Jersey Coastal Plain (by the PI and his colleagues) and offshore on the NJ shelf and slope (ODP) 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 evidence that such a link exists in the older, supposedly "ice-free" world; 3) 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. Backstripping results of sequences at Bass River and Ancora, NJ accounts for the effects of sediment loading, compaction, paleodepth, and basin subsidence, providing a new eustatic estimate. The PI's studies indicate that large (25m) and rapid (1m.y.) eustatic variations occurred in the Late Cretaceous Greenhouse world. This requires that either small ice sheets paced sea-level changes during this time, or our understanding of causal mechanisms for global sea-level change is fundamentally flawed. Foraminiferal oxygen isotope changes are consistent with a glacioeustatic cause. This award will allow the PIs to take advantage of an opportunity for joint funding and collaboration with the New Jersey Geological Survey (NJGS) and the US Geological Survey (USGS) by drilling a borehole on the coast of NJ near Manasquan, NJ that will provide the thickest marine Upper Cretaceous section in the region and tie to offshore MCS profiles obtained in 2002. These seismic profiles cross thick marine Upper Cretaceous strata, revealing sequence stratigraphic geometries for this Greenhouse interval; drilling at Manasquan will provide detailed age and facies controls on these seismic sequences. In addition, the NJGS is funding drilling costs for Upper Cretaceous targets at Millville, NJ (1500 ft) and Batsto, NJ (1500 ft.). Together, these 5 sites will provide updip-downdip and along-strike transects that will fully characterize the ages, facies, and distribution of Late Cretaceous sequences.The USGS Eastern Earth Surface Processes Team will drill a 1600 ft. borehole at Manasquan; and will follow this with a 1500-1600 ft. borehole at Batsto in Spring 2004