EGU2020-7973
https://doi.org/10.5194/egusphere-egu2020-7973
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Characterization of recent deep-sea debrites in the Eastern Mediterranean based on foraminiferal taphonomy

Oded Katz1, Leeron Ashkenazi1,2, Shani Sultan-Levi1, Sigal Abramovich2, Ahuva Almogi-Labin1, and Orit Hyams-Kaphzan
Oded Katz et al.
  • 1Geological Survey of Israel, Jerusalem, Israel
  • 2Department of Geological and Environmental Science, Ben Gurion University of the Negev, Beer-Sheva 8410501, Israel

It is hypothesized that submarine transport of sediments down a continental slope induce physical disintegration of pristine (non-broken) foraminifera shells, and thus mass transport deposits should include a significant percentage of fragmented shells. To validate this hypothesis, we studied two gravity-cores from the Eastern-Mediterranean continental slope, offshore Israel: AM113 sampled within a landslide lobe at 848 m water depth, and AM015 located away from a landslide at 1080 m. At least one interval, ~0.5 m thick, of massive sediments hosting mud-clasds (i.e. debrite) was identified within each core. The timing of these debrites, based on biostratigraphy, oxygen isotopes and total organic carbon data, predates sapropel S1 in both cores and is contemporaneous (AM113) or slightly predates (AM015) the most recent deglaciation.

We found a noticeable increase in benthic and planktic foraminiferal shells fragmentation through the last deglaciation and up to the base of S1. This strongly-fragmented sequence is located in the debrite of AM113 but it is overlaying the debrite of AM015. Accordingly, we suggest two possible mechanisms for the increased fragmentation of foraminiferal shells in both cores: Sediment transport and turbulence related to submarine mass-transport events, or geochemical changes in the lower water column properties at the transition from MIS-2 to the Holocene.

How to cite: Katz, O., Ashkenazi, L., Sultan-Levi, S., Abramovich, S., Almogi-Labin, A., and Hyams-Kaphzan, O.: Characterization of recent deep-sea debrites in the Eastern Mediterranean based on foraminiferal taphonomy, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7973, https://doi.org/10.5194/egusphere-egu2020-7973, 2020

Displays

Display file