Extensive glaucony-rich sediment was recovered at Site 903 of Ocean Drilling Program Leg 150, drilled on the upper slope of the New Jersey Margin. Sedimentological, petrological, and geochemical analyses were undertaken on six glaucony-rich intervals (G1-G6) of late Oligocene, Miocene, and middle Pliocene-early Pleistocene age. Three characteristics must be considered in the sequence-stratigraphic interpretation of glaucony-rich sediment on the slope: (1) the degree of reworking undergone by the glaucony prior to its final deposition; (2) the relative abundances of terrigenous and biogenic material in the glaucony-rich unit; and (3) the sedimentological and diagenetic characteristics of the lower boundary of the glaucony-rich unit. In contrast to typical shelf settings, the glaucony-rich sediments observed in Site 903 were deposited during three different stages within the depositional sequence: during sediment starvation of the basin during maximum transgression (G1 and G2: late Oligocene to early Miocene), during early highstand (G3, G4, and G5: middle to late Miocene), and during lowstand (G6: middle Pliocene–early Pleistocene).

Date of initial receipt: 9 March 1995
Date of acceptance: 17 October 1995

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