Were deforming subglacial beds beneath past ice sheets really widespread?

Jan A. Piotrowski a * jan.piotrowski@geo.aau.dk, David M. Mickelson b davem@geology.wisc.edu, Slawek Tulaczyk c smula0@pop.uky.edu, Dariusz Krzyszkowski d dk2@wro.top.pl and Frank W. Junge e junge@rz.uni-leipzig.de

a Department of Earth Sciences, University of Aarhus, C.F. Møllers Allé 120, DK-8000 Århus C, Denmark
b Department of Geology and Geophysics, Weeks Hall, University of Wisconsin, 1215 West Dayton Street, Madison, WI 53711, USA
c Department of Geological Sciences, 101 Slone Building, 0053, University of Kentucky, Lexington, KY 40506-0053, USA
d Institute of Geography, WSP Supsk, Partyzantów 27, PL-76-200 Supsk, Poland
e Institute of Geophysics and Geology, University of Leipzig, Talstraße 35, D-04103 Leipzig, Germany

Abstract

The concept of widespread, large-strain deformation of subglacial unconsolidated, unfrozen, sediments during Pleistocene glaciations has inconsistencies in the geological record. Numerous properties of tills and related sediments are difficult to reconcile with pervasive strains, as predicted by the deforming bed theory. While accepting glacier-bed deformation as a geological process occurring under certain circumstances, we propose that it was much less widespread than believed by some. Instead, we believe that basal sliding and englacial transport are major ice movement and debris-transport mechanisms.

Note the full reply to comments of Boulton et al. on this article are linked to publication 02-7.