19. PALEOCENE BENTHIC FORAMINIFERAL BIOFACIES AND SEQUENCE STRATIGRAPHY, ISLAND BEACH BOREHOLE, NEW JERSEY1

Chengjie Liu,2 James V. Browning,2 Kenneth G. Miller,2,3 and Richard K. Olsson2

ABSTRACT

Benthic foraminiferal biofacies and integrated stratigraphic studies of the sediments recovered from the Island Beach borehole in New Jersey reveal that the Paleocene strata penetrated in the borehole can be divided into three sequences, which we designate pa1, pa2, and pa3 in stratigraphically ascending order. Sequence boundaries are recognized by gamma-ray log excursions, hiatuses, and unconformities. Depositional paleoenvironments for each sequence are recognized by lithology and benthic foraminiferal biofacies. Strata in these sequences exhibit upward shallowing from outer neritic to middle neritic environments. Maximum flooding surfaces are associated with the greatest benthic foraminiferal biofacies changes, shell beds, and secondary gamma-ray kicks. Biofacies changes across sequence boundaries are less severe; we attribute this to the effects of a longer term decrease in water depth superimposed on these shorter-term transgressive/regressive cycles.

1Miller, K.G., and Snyder, S.W. (Eds.), 1997. Proc. ODP, Sci. Results, 150X: College Station, TX (Ocean Drilling Program).
2Department of Geological Sciences, Rutgers University, Piscataway, NJ 08854, U.S.A. cheliu@rci.rutgers.edu
3Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, U.S.A.