Titre

Stable isotopic fractionation, climate change and episodic stagnation in the eastern Mediterranean during the late Quaternary

Année de publication

1977

Source

Marine Micropaleontology 1977 2 353 370

ISSN
0377-8398
Résumé

Abstract: Fluctuations in the δ18O composition of planktonic foraminifers in eastern Mediterranean piston cores indicate cycles with amplitudes much greater than those which can be attributed alone to global ice-volume changes. Isotopic values become markedly negative within lithostratigraphic levels characterized by the apparition of organicrich sapropels These owe their origin to the development of euxinic bottom water during episodes of basin-wide stagnation. The depletion of δ18O in many of the sapropels is accompanied by the occurrence of poorly diversified planktonic faunas, and both phenomena are attributed to a strong dilution of the local eastern Mediterranean surface water mass by a combination of glacial run off from large continental ice sheets and by an important increase of regional precipitation synchronous with the transition from pleniglacial to kataglacial climate.Although sapropel accumulation occurs generally during intervals of warming of the Mediterranean region as determined from a quantitative evaluation of planktonic foraminiferal assemblages, the pre-125,000 years, local warming of eastern Mediterranean surface water lagged the acme of glacial melting by up to 15,000 years. Climatic and isotopic cycles are correlative within the eastern Mediterranean for lateral distances in excess of 1000 km and, except for amplitude and phase, they are in most aspects remarkably similar to those recorded in the equatorial Pacific and Caribbean.

Type de publication
  • journal
Type de document
  • research-article
Classification
 
Classification - Inist-CNRS
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Classification - Scopus
  • 1 - Physical Sciences
  • 2 - Earth and Planetary Sciences
  • 3 - Palaeontology
  • 3 - Oceanography
Classification - Science Metrix
  • 1 - natural sciences
  • 2 - earth & environmental sciences
  • 3 - paleontology
Classification - Clarivate Analytics (Subject Category)
  • 1 - science
  • 2 - paleontology
Termes extraits

sapropel; salinity; faunal; quaternary; climatic; eastern mediterranean; cita; glacial; shackleton; geol; pleistocene; isotopic; ruber; eggeri; planktonic; isotope; substage; stratigraphic; emiliani; isotopic signal; opdyke; precipitation; bonatti; stratigraphy; tephra; inflata; meltwater; ruddiman; mediterranean; stagnation; climatic faunal curve; planktonic foraminifers; equatorial; isotopic change; late cenozoic; isotopic composition; excess evaporation; mcintyre; yale university press; tephra layer; isotopic signals; open ocean; late quaternary; core vema; factor analysis; stratigraphic position; isotopic variations; pollen record; isotopic stages; last years; mediterranean region; lowest occurrence; climatic record; isotopic values; sapropel deposition; deep waters; temperature effect; episodic stagnation; magnesium calcite; radiocarbon suppl; isotopic variation; glacial meltwater; black seas; other cores; thermal stratification; positive shifts; surface water; salinity faunal index; isotopic analysis; planktonic foraminifera; river runoff; eastern mediterranean surface water; paleomagnetic stratigraphy; surface salinity; mediterranean watershed; emiliania huxleyi; highest occurrence; last pleniglacial; white nile; equatorial atlantic; cold intervals; faunal curve; cold interval bracketing sapropel; surface ocean warming; tropospheric circulation; significant volume; large amplitude; radiocarbon measurements; mediterranean sediments; pseudoemiliania lacunosa; surface ocean salinity; national science foundation; late pleistocene; sedimentation rate; climate change; chronostratigraphic position; main features; geological composition; hydrological regime; faunal curves; evaporation; sediment

Entité nommée
 
Entité nommée - Emplacement géographique
  • U.S.
  • Macedonia
  • Europe
  • N.Y.
  • Palisades
  • France
  • Italy
  • Spain
Entité nommée - Organisme
  • National Science Foundation
  • Department of Geology and Paleontology
  • University of Milan
  • Columbia University
  • Macedonia, Greece
  • Naval Research Contract No
Entité nommée - Personne
Goesta; David Ericson; Pacific Core; G. Orombelli; M.B. Cita; C. Vergnaud-Grazzini; Floyd W. McCoy; Observatory; Andrew McIntyre; Dragoslav Ninkovich; W.B.F. Ryan; William F. Ruddiman; H. Thierstein
ark:/67375/6H6-7Z2F0HM2-9
Powered by Lodex 8.19.1