Ocean Drilling Program (ODP) Leg 210 Site 1276 is located in the deep Newfoundland Basin, east of the Grand Banks and south of the Flemish Cap (45°24.3198´N, 44°47.1496´W) in 4549 m of water (Tucholke, Sibuet, Klaus, et al., 2004). The site was cored in the interval from 800.0 to 1736.9 meters below seafloor (mbsf) with 85% core recovery. The principal scientific objectives of ODP Leg 210 focused on the rifting and postrift sedimentation of the Newfoundland continental margin in relation to the conjugate Iberian continental margin. They represent nonvolcanic rifted margins, and ODP Leg 210 is the first coring on the western side of the rift. Site 1276 was drilled on transitional crust adjacent to oceanic crust of probable Barremian age based on the interpretation of magnetic Anomaly M3 (Tucholke, Sibuet, Klaus, et al., 2004) (Fig. F1). Site 1277 was drilled on a shallow basement high ~40 km southeast of Site 1276. Secondary drilling objectives of ODP Leg 210 included the paleoceanographic history at the northern edge of the central North Atlantic as the gateway to the northern North Atlantic began to open during the Early Cretaceous. The Cretaceous–Paleogene interval was a time of major paleoceanographic events including oceanic anoxic events of the mid-Cretaceous, the Cretaceous/Paleogene boundary, and the Paleocene/Eocene Thermal Maximum. In addition, seafloor spreading and ocean gateway deepening and widening at both ends of the central North Atlantic played a major role in changing surface and deepwater circulation during this time.
From Hole 1276A we recovered a 936.9-m-thick succession of mudrock, shale, and interbedded turbidite sandstone and other gravity flow deposits spanning ~80 m.y. of the mid-Cretaceous to early Oligocene (~113–33 Ma). Despite the pervasive redeposited nature of the sedimentary succession cored at Site 1276, the paleontological findings reported here provide a robust temporal framework for the largely uninterrupted record of changing paleoenvironmental conditions of the surface ocean and in the deep Newfoundland Basin. This synthesis incorporates new paleontological results since the publication of the Leg 210 Initial Reports volume (Tucholke, Sibuet, Klaus, et al., 2004). It provides a detailed revision of the calcareous nannofossil biostratigraphy, as well as an updated discussion of sedimentation history and comprehensive summary of North Atlantic paleoceanography based on paleontological data from Site 1276. Site 1277 is not included in this analysis because of the paucity of sediment and lack of age-diagnostic fossils.