ALBERT

Description: A major objective of DSDP Leg 95 (New Jersey Transect) was to investigate the effects of eustatic sea-level fluctuation and crustal subsidence on the depositional and erosional patterns of the Atlantic continental margin in the Baltimore Canyon trough area. Deep Sea Drilling Project Sites 612 and 613 were drilled on the New Jersey continental slope and rise during this leg. A more specific goal of Leg 95 was to investigate calcareous and siliceous microfossil biostratigraphy in order to identify biostratigraphic gaps and to intercorrelate the various microfossil zonations for the New Jersey margin. This study of radiolarians from Sites 612 and 613, and from Atlantic Slope Project (ASP) Site ASP 15, demonstrates that although radiolarians occur throughout the Cenozoic section in this region, they are most useful for biostratigraphic control in the upper Paleogene part of the stratigraphic record. Results of this investigation indicate that several biostratigraphic gaps occur in the Cenozoic sedimentary sequence penetrated by the three drill holes. Upper Paleogene radiolarians are well preserved, abundant, and diverse. Although some tropical taxa are rare or absent, sufficient age-diagnostic species are present for biostratigraphic determinations. In comparison, lower Paleogene radiolarians are poorly preserved because pronounced silica diagenesis formed porcellanites in some stratigraphic intervals. The Neogene radiolarians faunas are rare and moderately well preserved at all the sites investigated here. Neogene assemblages are dominated by spongodiscids and porodiscids (similar to faunas of modern cold/temperate shelf waters), and contain few taxa useful for biostratigraphic determinations.