The Postglacial Isotopic Record of Intermediate Water Connects Mediterranean Sapropels and Organic‐Rich Layers

Alessandro Incarbona, Mario Sprovieri

Risultato della ricerca: Articlepeer review

Abstract

Carbon‐rich layers exist at both sides of the Mediterranean Sea sedimentary record and arecalled sapropels and organic rich layers (ORLs), respectively, in the eastern and western basins. Theyhave different levels of organic carbon accumulation and seafloor oxygen deprivation. The most recentsapropel and ORL depositions have a different timing, approximately 10.8–6.1 and 14.5–9.0 ka, respectively.Here we investigate oxygen isotopic records of three foraminifera species that occupy different habitatswithin the Sicily Channel water column since ~12.0 ka, thus in the sill between the eastern and westernMediterranean basins. These data are ice volume corrected, to get information on water masses densityvariability, and are accompanied by benthic foraminifera δ13C measurements to establish Sicily Channelseafloor ventilation. Our results, and the comparison with other chronologically well‐constrainedMediterranean records, highlight the connection of the two subbasins due to monsoon activity. The end ofthe maximum Nile River flooding at ~9.2 ka, and eastern Mediterranean seafloor reventilation above1,800–1,500 mdepth at ~ 8.2 and 7.2 ka, left a clear signature in the intermediate water isotopic record of theSicily Channel. Concurrently, the western Mediterranean deep water circulation experienced asignificant recovery after a long period of slowdown. We argue that African monsoon weakening wastransmitted into the western Mediterranean, through the intermediate layer of circulation, where deepwater formation took place and brought oxygen to the seafloor.
Lingua originaleEnglish
pagine (da-a)1-20
Numero di pagine20
RivistaPaleoceanography and Paleoclimatology
Volume35
Stato di pubblicazionePublished - 2020

All Science Journal Classification (ASJC) codes

  • Oceanography
  • Atmospheric Science
  • Palaeontology

Cita questo