2002 Denver Annual Meeting (October 27-30, 2002)

Paper No. 6
Presentation Time: 2:55 PM


MILLER, Kenneth G.1, SUGARMAN, Peter2, BROWNING, James V.1, KOMINZ, Michelle A.3, HERNANDEZ, John C.4, OLSSON, Richard K.4, KATZ, Miriam E.4 and WRIGHT, James D.4, (1)Department of Geological Sciences, Rutgers, The State Univ of New Jersey, 610 Taylor Rd, Piscataway, NJ 08854-8066, (2)New Jersey Geol Survey, PO Box 427, Trenton, NJ 08625, (3)Geosciences, Western Michigan University, 1187 Rood Hall, Kalamazoo, MI 49008-3805, (4)Department of Geological Sciences, Rutgers, The State University of New Jersey, 610 Taylor Rd, Piscataway, NJ 08854-8066, kgm@rci.rutgers.edu

Drilling by ODP Leg 174AX provided a record of 12-15 Upper Cretaceous sequences in the New Jersey (NJ) Coastal Plain that provides the basis for reconstructing the timing and amplitude of sea-level variations; integration of Sr-isotopic and bio- stratigraphy provides a chronology for these sequences with a resolution of ~±0.5 m.y. We provide a backstripped Late Cretaceous sea-level record using these sequences, taking into account sediment loading, compaction, paleo-water depth, and basin subsidence. Here we show that sea-level changes were large (>25 m) and rapid (<<1 m.y.), strongly suggesting a glacioeustatic control of sea-level variations during the Late Cretaceous. The NJ Late Cretaceous sequence boundaries generally correspond in age with sea-level lowerings of Exxon Production Research (EPR), NW European and Russian sections, indicating a global cause, though previous EPR amplitudes are too large by a factor of 2. Oxygen isotopic data, a proxy for ice volume and paleotemperatures, are consistent with a glacioeustatic cause. Comparison of sea-level records with other changes in the geobiosphere (e.g., extinctions, adaptive radiations, ocean anoxic events, carbon isotopic variations) show that long-term (10-m.y.-scale) sea-level changes are associated with the general diversification of Mesozoic phytoplankton, but there is little correlation on the m.y.-scale.