Correlating Pleistocene sequences across the New Jersey margin

The biostratigraphic ranges of palynomorphs, as well as climatostratigraphi c changes recorded by both marine and terrestrial palynomorphs, provide one of the few means of dating and correlating neritic environments where calc areous microfossils are rare. The transport of terrestrial palynomorphs to marine environments also allows for direct land-sea correlation. In additio n, palynological assemblages provide insights into sediment transport and s ea levels. Over 500 m of upper Pleistocene sediments were recovered in ODP Hole 1073A on the upper New Jersey slope. Palynomorphs in this Hole record rapid progr adation during the late Pleistocene. A prominent unconformity, pp3(s), form s the upper boundary of this thick progradational sequence. Palynological a nalysis from ODP Sites 1072 and 1073 allows this surface to be correlated f rom the outer shelf to the upper slope, and also suggests that it was gener ated during a sea level lowstand, probably during Oxygen Isotope Stage 12 ( similar to 450-425 ka). Both the Atlantic Coastal Plain and ODP Site 1072 o n the outer New Jersey shelf appear to have become erosional during this pr ogradational phase which began around the time that the magnitude of Northe rn Hemisphere ice accumulation increased. This suggests that sediments prog raded across the New Jersey margin as accommodation in inner neritic and co astal environments decreased in response to amplified glacioeustatic fluctu ation and substantially increased sediment availability (supplied by glacia l erosion). Erosion associated with the generation of unconformity pp3(s) a ppears to have increased accommodation on the New Jersey margin, allowing s ediments to aggrade on the continental shelf and even to accumulate on the Atlantic Coastal Plain during interglacial highstands. The upper Pleistocen e architecture of the New Jersey margin appears to have been controlled by glacioeustatic fluctuations and the accompanying increase in sediment suppl y. In contrast, unconformable surface pp4(s) is more complex and separates upp er Miocene sediments deposited between 7.4 and 5.9 Ma from lower Pleistocen e sediments deposited prior to approximately 1.4 Ma in Hole 1072A, whereas in Hole 1073A, pp4(s) is in sediments of early Pleistocene age, between 1.6 and 1.3 Ma. These data suggest that unconformity pp4(s) was generated duri ng the early Pleistocene, but there is no clear palynological evidence that glacioeustasy was responsible for the generation of this unconformity. (C) 2000 Elsevier Science B.V. All rights reserved.