Debris entrainment at the ice-bedrock interface in sub-freezing temperature conditions (Terre Adelie, Antarctica)

• Main Authors: Tison, Jean-Louis, Petit, Jean-Robert, Barnola, Jean-Marc, Mahaney, William W.C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1993
• Subjects: Géologie et minéralogie; Antarctic; Antarc*; Antarctica; ice core; Journal of Glaciology
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/219452

The debris-rich ice from the bottom 6 m of the 82 m deep CAROLINE (Coastal Antarctic Record of Last Interglacial Natural Environment) ice core reaching bedrock, and from five 2 m long surface cores at Moraine Prudhomme in Terre Adelie (Antarctica) is described and compared to debris-laden ice from the core-drilling site D10. Isotopic, total-gas content, CO2 concentration and SEM investigations of embedded particles, together with ice textures and fabrics, rule our "pressure-melting' regelation around bed obstacles or "freezing-on' as possible mechanisms for the debris entrainment at the ice-bedrock interface. It is suggested that the debris entrapment by purely mechanical means (e.g. shearing) is an efficient process in forming basal ice layers (BIL) at sub-freezing temperatures. -from Authors SCOPUS: NotDefined.j info:eu-repo/semantics/published