Labrador Sea bio-, tephro-, oxygen isotopic stratigraphy and Late Quaternary paleoceanographic trends
- 1 July 1980
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Earth Sciences
- Vol. 17 (7), 831-854
- https://doi.org/10.1139/e80-083
Abstract
A stratigraphic framework for eastern Labrador Sea cores was developed for the interval 0-90,000 yr BP through analysis of O2 isotopes, volcanic ash, benthonic foraminifera and the radiolarian Diplocyclas davisiana. Benthonic and planktonic foraminiferal isotope stratigraphy and the time scale of Shackleton and Opdyke provide a basis for the approximate dating of a series of marker events which include ash zones at .apprx. 59,000 and .ltoreq. 21,000 yr BP; benthonic foraminiferal abundance maxima at .apprx. 83,000, 75,000, 60,000, 19,000 and 3000 yr BP; and D. davisiana percentage maxima at .apprx. 90,000, 73,000, 64,000, 54,000, 45,000-32,000 and 10,000 yr BP. Incursions of subpolar planktonic foraminifera into the area during parts of isotopic stage 2 (between about 13,000 and 25,000 yr BP but probably excluding the 15,000-18,000 yr BP glacial maximum interval) and during the isotopic stage 4/5a transition (around 75,000 yr BP) suggest that the eastern Labrador Sea was free of sea ice, at least in summer during periods of rapid continental ice sheet growth which lead to the isotopic stage 4 and stage 2 glacial maxima. A larger than normal stage 1/stage 2 difference in the isotopic composition of benthonic foraminifera (1.8.permill.) implies that this open water and attendant surface cooling was a potential source for colder than modern deep water. The Norwegian Sea was a reservoir of warmer than modern deep water during the last glacial.Keywords
This publication has 4 references indexed in Scilit:
- Planktonic foraminiferal and oxygen isotopic stratigraphy and paleoclimatology of Norwegian Sea deep‐sea coresBoreas, 1978
- Ecology of Planktonic Foraminifera and Biogeographic Patterns of Life and Fossil Assemblages in the Indian OceanMicropaleontology, 1977
- Controls on the Preservation of Biogenic Opal in Sediments of the Eastern Tropical PacificScience, 1976
- Late Pleistocene Benthic Foraminifera of the Southern Champlain Sea: Paleotemperature and Paleosalinity IndicationsAtlantic Geology, 1974