EGU21-11181, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sedimentological characterization of coarse sediments within the deglaciation sequence in the east Antarctic Wilkes Land margin

Julia Gutierrez-Pastor1, Carlota Escutia1, Ursula Röhl2, Ariadna Salabarnada3, and Francisco Jimenez-Espejo1
Julia Gutierrez-Pastor et al.
  • 1Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), CSIC , Armilla, Granada, Spain (
  • 2MARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany (
  • 3Igeotest, Sant Cugat del Vallés, Barcelona, Spain (

During the Holocene, 180 m of diatom ooze sediments were deposited in the Antarctic Wilkes Land margin continental shelf at site U1357A (Integrated Ocean Drilling Program Expedition 318, Escutia et al., 2011). Holocene sediments are dominated by rhythmic laminated deposits above a poorly sorted gravelly siltstone diamicton from the Last Glacial Maximum (LGM). CT-scans reveal three events of gravel/sand/silt sediments interbedded within the laminated sediments and interpreted as ice rafted debris (IRD).  Two of these events (from 185,1 to 185,45 and 174, 8 to 175,37 meters below seafloor, mbsf) are characterized by dispersed large clasts (1-5cm) within a muddy matrix at the base, transitioning to the top to millimetre-size clasts that are either aligned with the dark and light laminae or dispersed. A third event (176,2 to 177,2 mbsf) is characterized by a structureless sediment sequence with high concentrations of dispersed clasts that are up to 1-2 cm size. We used ImageJ/Fiji software, to conduct a quantitative analysis of grains bigger than 1mm in CT Scan 3D images. Measured parameters include grain size (Feret length), grain orientation (Feret angle), circularity and roundness, among other. In addition, grey scale profiles have been created from the sediment CT-scan images as a density proxy. Quantitative data and density profiles have been used to aid the sedimentological characterization of the Holocene deglaciation section and to infer depositional environment and patterns of deglaciation.

Escutia, C., Brinkhuis, H., Klaus, A., and the Expedition 318 Scientists, Proc. IODP, 318: Site 1357. Tokyo (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/​iodp.proc.318.105.2011


How to cite: Gutierrez-Pastor, J., Escutia, C., Röhl, U., Salabarnada, A., and Jimenez-Espejo, F.: Sedimentological characterization of coarse sediments within the deglaciation sequence in the east Antarctic Wilkes Land margin, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11181,, 2021.

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