7. Oligocene–early Miocene dinocyst stratigraphy of Hole 985A (Norwegian Sea)1

Graham L. Williams2 and Svein B. Manum3

ABSTRACT

The rich and diverse dinocyst assemblages in Cores 162-985A-32X through 62X confirm the importance of these microfossils in unraveling the evolution of the Norwegian Sea. Cosmopolitan taxa, with well-documented stratigraphic ranges in northwest Europe, indicate the following ages: Sections 162-985A-62X-1 through 51X-2, Rupelian (early Oligocene); 50X-5, Oligocene, possibly Chattian; 48X-6, Aquitanian? (early Miocene); 48X-4 through 37X-5, Aquitanian (early Miocene); and 36X-5 through 32X-1, Burdigalian (early Miocene). This stratigraphic interpretation suggests that a major hiatus, which can be correlated with an apparently coeval hiatus at Site 643, occurs within the Chattian at Site 985. Several endemic dinocyst taxa with unusual morphology and restricted stratigraphic occurrences are present in Hole 985A and other Norwegian Sea sites, especially Site 643. By using Hole 985A data for control, the Oligocene-Miocene sediments can be correlated with some degree of confidence in the Norwegian Basin.

1Raymo, M.E., Jansen, E., Blum, P., and Herbert, T.D. (Eds.), 1999. Proc. ODP, Sci. Results, 162: College Station, TX (Ocean Drilling Program).
2Geological Survey of Canada (Atlantic), P.O. Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada. gwilliam@agc.bio.ns.ca
3Department of Geology, P.O. Box 1047, Blindern, N-0316 Oslo, Norway.

Date of initial receipt: 3 September 1997
Date of acceptance: 30 April 1998
Ms 162SR-030
 

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