Benthic foraminifera in sapropels of the eastern Mediterranean Sea, supplement to: Schmiedl, Gerhard; Mitschele, A; Beck, S; Weldeab, Syee; Schulz, Hartmut; Hemleben, Christoph; Sperling, Michael R; Emeis, Kay-Christian (2003): Benthic foraminiferal record of ecosystem variability in the eastern Mediterranean Sea during times of sapropel S5 and S6 formation. Palaeogeography, Palaeoclimatology, Palaeoecology, 190, 139-164

DOI

High-resolution benthic foraminiferal and geochemical investigations were carried out across sapropels S5 and S6 from two sediment cores in the Levantine Sea to evaluate the impact of climatic and environmental changes on benthic ecosystems during times of sapropel formation. The faunal successions indicate that eutrophication and/or oxygen reduction started several thousand years prior to the onset of sapropel formation, suggesting an early response of the bathyal ecosystems to climatic changes. Severest oxygen depletions appear in the early phases of sapropel formation. The initial reduction of deep-water ventilation is caused by a warming and fresh water-induced stratification of Eastern Mediterranean surface waters. During the late phase of S5 formation improved oxygenation is restricted to middle bathyal ecosystems, indicating that at least some formation of subsurface water took place. During S6 formation oxygen depletions and eutrophication were less severe and more variable than during S5 formation. Estimated oxygen contents were low dysoxic at middle bathyal to anoxic at lower bathyal depths during the early phase of S6 formation but never dropped to anoxic values in its late phase. The high benthic ecosystem variability during S6 formation suggests that water column stratification at deep-water formation sites was in a very unstable mode and susceptible to minor temperature fluctuations at a millennial time-scale.

Identifier
DOI http://dx.doi.org/doi:10.1594/PANGAEA.736661
Metadata Access http://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite3&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.736661
Provenance
Creator Schmiedl, Gerhard;Schulz, Hartmut;Mitschele, A;Emeis, Kay-Christian;Weldeab, Syee;Hemleben, Christoph;Sperling, Michael R;Beck, S
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2003
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Coverage
Discipline Earth System Research
Spatial Coverage (33N-35N,27E-34E)
Temporal Point 1998-01-23T11:59:59Z