Dinocyst assemblages of site HM52-43
Citation
de Vernal A, Hillaire-Marcel C, Turon J, Matthiessen J (1999). Dinocyst assemblages of site HM52-43. PANGAEA - Publishing Network for Geoscientific and Environmental Data. Occurrence dataset https://doi.org/10.1594/pangaea.79362 accessed via GBIF.org on 2018-08-19.Description
Past sea-surface conditions over the northern North Atlantic during the last glacial maximum were examined from the study of 61 deep-sea cores. The last glacial maximum time slice studied here corresponds to an interval between Heinrich layers H2 and H1, and spanning about 20-16 ka on a 14C time scale. Transfer functions based on dinocyst assemblages were used to reconstruct sea-surface temperature, salinity, and sea-ice cover. The results illustrate extensive sea-ice cover along the eastern Canadian margins and sea-ice spreading, only during winter, over most of the northern North Atlantic. On the whole, much colder winter prevailed, despite relatively mild conditions in August (10-15°C at most offshore sites), thus suggesting a larger seasonal contrast of temperatures than today. Lower salinity than at present is reconstructed, especially along the eastern Canadian and Scandinavian margins, likely because of meltwater supply from the surrounding ice sheets. These reconstructions contrast with those established by CLIMAP on the basis of planktonic foraminifera. These differences are discussed with reference to the stratigraphical frame of the last glacial maximum, which was not the coldest phase of the last glacial stage. The respective significance of dinocyst and foraminifer records is also examined in terms of the thermohaline characteristics of surface waters and the vertical structure of upper water masses, which was apparently much more stratified than at present in the northern North Atlantic, thus preventing deep-water formation.Taxonomic Coverages
Geographic Coverages
Bibliographic Citations
Contacts
Anne de Vernaloriginator
Claude Hillaire-Marcel
originator
Jean-Louis Turon
originator
Jens Matthiessen
originator
metadata author
PANGAEA - Data Publisher for Earth & Environmental Science
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administrative point of contact
PANGAEA - Data Publisher for Earth & Environmental Science
email: info@pangaea.de
homepage: http://www.pangaea.de