Data Report: No significant occurrences of diatoms, silicoflagellates, or ebridians in lower Eocene through lower Miocene sediments of the southeast Greenland Margin

Abstract

Sediments recovered at Deep Sea Drilling Project (DSDP) Leg 38 Sites 336–340, and 342 established that the Norwegian-Greenland Sea, north of the Greenland-Scotland Ridge, was host to rich diatom, silicoflagellate, and ebridian communities during much of the middle to late Paleogene (Dzinoridze et al., 1978; Schrader and Fenner, 1976; Martini and Muller, 1976). Recent studies by Scherer and Koc (1996) and Locker (1996), which resulted from drilling in the northern Norwegian-Greenland Sea during Ocean Drilling Program (ODP) Leg 151, contributed significant new data toward the development of a regional late Paleogene biosiliceous phytoplankton biostratigraphy, although the recovered stratigraphic record remains incomplete. High Paleogene diatom productivity in relatively shallow waters in the high northern latitudes is evident from diatomaceous sediments known from outcrop (Benda, 1972; Homann, 1991) and borehole studies (Fenner, 1994) on Jutland (Denmark) and from outcrop studies in western Kazakhstan and the Urals (e.g., Gleser and Posnova, 1964; Krotov and Shibkova, 1959; Gleser et al., 1974; 1992). Diatomaceous Eocene sediments were recovered in a single short core from the Alpha Ridge in the central Arctic Ocean (Dell’Agnese and Clark, 1994). Lower Paleogene diatoms that occur in the Russian and Danish deposits have been documented as reworked specimens in glacial sediments in northern Scandinavia (Cleve-Euler, 1941; Tynni, 1982) and in glacial-marine sediments of the northern Barents Sea (Grunow, 1884; Polyakova et al., 1992; Myhre, Thiede, Firth, et al., 1995; Scherer and Koc, 1996). These occurrences suggest that diatomaceous sediments were deposited across the broad, shallow seas that covered the northern European lowlands during Paleogene highstands of sea level. These deposits were subsequently eroded, transported and redeposited during Pleistocene glacial events in Fennoscandia, in most cases leaving no trace of the original strata. Paleogene biosiliceous phytoplankton microfossils also have been documented in the high latitude North Atlantic region, south of the Greenland-Scotland Ridge. Sporadic occurrences of Eocene diatom-bearing sediments have been reported, including those from DSDP drilling at Sites 553 (Leg 81) (Baldauf, 1984; Palmer, 1984) and 405 (Leg 48) on the Rockall Plateau, Sites 400 and 402 (Leg 48) in the Bay of Biscay, and Site 384 (Leg 43) on the North American continental margin, south of the Grand Banks (all in Palmer, 1984). Upper upper Eocene to lower lower Oligocene diatomaceous sediments were recovered from the Labrador Sea at DSDP Site 112 (Leg 12; Burckle, 1972) and ODP Site 647 (Leg 105) (Baldauf and Monjanel, 1989).