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Kevin MacNeil

a86-km

B. Sc. Honours Thesis

Late Pleistocene-Holocene Paleoceanography of the Northeast Newfoundland Shelf; Benthonic Foraminiferal Evidence

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A micropaleontological study based on benthonic foraminifera was made of seventy-one samples from core 80-030-26 (Gravity and Piston) taken at a water depth of 267 m in outer Notre Dame Bay, northeast Newfoundland Shelf. The data obtained were compared with the pollen data from the gravity core and piston core top. These results were correlated with those from previous work on the northeast Newfoundland Shelf.

Late Pleistocene paleoceanography until 10,000 BP was characterised by an Elphidium excavatum f. clavata-Cassidulina reniforme "warm" ice margin fauna, interrupted in early postglacial time by an important local meltwater input event. Substantial bottom water cooling occurred at the base of the Holocene as indicated by abundance of agglutinated forms, followed by a gradual warming indicated by the abundance of warmer water calcareous fauna from 5000- 7000 years BP. There has been a marked cooling in the last 2500 years represented by the presence of an exclusively agglutinated assemblage at the core surface.

Bottom water temperatures on the inner northeast Newfoundland Shelf are colder now than at any time since the last deglaciation. Temperature gradients on the eastern Canadian continental margin have been increasing in the last 2500 years, possibly representing a cold pre-glacial phase providing conditions for the onset of a glacial stage.

Keywords:
Pages: 55
Supervisor: David Scott