TY - CHAP
T1 - Characterization of recent deep-sea debrites in the eastern mediterranean based on foraminiferal taphonomy
AU - Katz, Oded
AU - Ashkenazi, Leeron
AU - Levi, Shani Sultan
AU - Abramovich, Sigal
AU - Almogi-Labin, Ahuva
AU - Hyams-Kaphzan, Orit
N1 - Funding Information:
This study was funded by the Israel Science Foundation (grant No. 954/15) to Oded Katz and by the Chief Scientist office of the Ministry of Energy, Israel (grant No. 76/17) to Oded Katz and Orit Hyams-Kaphzan.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/1/1
Y1 - 2020/1/1
N2 - It is hypothesized that submarine transport of sediments down a continental slope induces physical disintegration of pristine (non-broken) foraminiferal 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, c. 0.5 m thick, of heterogeneous sediments (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 the fragmentation of benthic and planktic foraminiferal shells through the last deglaciation and up to the base of S1. This strongly fragmented sequence is located in the debrite of AM113 but overlays 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 masstransport events, or geochemical changes in the lower water column properties at the transition from MIS-2 to the Holocene.
AB - It is hypothesized that submarine transport of sediments down a continental slope induces physical disintegration of pristine (non-broken) foraminiferal 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, c. 0.5 m thick, of heterogeneous sediments (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 the fragmentation of benthic and planktic foraminiferal shells through the last deglaciation and up to the base of S1. This strongly fragmented sequence is located in the debrite of AM113 but overlays 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 masstransport events, or geochemical changes in the lower water column properties at the transition from MIS-2 to the Holocene.
UR - http://www.scopus.com/inward/record.url?scp=85087351520&partnerID=8YFLogxK
U2 - 10.1144/SP500-2019-170
DO - 10.1144/SP500-2019-170
M3 - Chapter
AN - SCOPUS:85087351520
T3 - Geological Society Special Publication
SP - 377
EP - 391
BT - Geological Society Special Publication
PB - Geological Society of London
ER -