Cretaceous paleoceanography of the western North Atlantic Ocean

Abstract

In this paper we summarize available information on the Cretaceous lithostratigraphy and paleoceanography of the western North Atlantic. The data and some of our interpretations draw in large part on papers published in the Deep Sea Drilling Project (DSDP) volumes. We have attempted to cite relevant references when possible, but space limitations make it difficult to give proper credit to all sources; we apologize for any omissions. Organic carbon (Corg) and carbonate (CaCO 3 ) analyses were tabulated for each site from papers in the DSDP Initial Report volumes and other published works (e.g., Summerhayes,1981). Corg, CaCO 3 , and non-CaCO 3 mass accumulation rates (MARS) were calculated using core by core averages of component percentages for the more continuously cored sites; core averages for wet bulk density and porosity (from DSDP data files); biostratigraphies of de Graciansky and others (1982), Roth and Bowdler (1981), and Cool (1982); and the time scales of the Decade of North American Geology (Palmer, 1983; Kent and Gradstein, this volume) or Harland and others (1982; see Plate 1). Backtracked paleodepths for western North Atlantic DSDP Sites from Tucholke and Vogt (1979) with the revised stratigraphy of de Graciansky and others (1982) were used in plotting Corg and CaCO 3 in Figures 2, 3, 4 and 5 (see also Thierstein, 1979). Backtracking curves of seafloor paleodepth versus age (Sclater and others, 1977; Tucholke and Vogt, 1979) for selected western North Atlantic DSDP sites. Average CaCO 3 concentrations per core are shown by code number