Earth and Atmospheric Sciences, Department of


Date of this Version



U.S. Geological Survey Open-File Report 87-262


The surficial sediments present on the continental shelf off the north coast of Alaska in the vicinity of Harrison Bay consist dominantly of fine grained sand, silt, and mud that were deposited during Holocene time. Depositional environments in Harrison Bay range from outer shelf to prodelta and delta front. Ice sediment interaction has overprinted structural deformation on many of the sediments present in Harrison Bay, and has in some cases obliterated the original lithologic continuity of the sediments. Ice related deformation ranges from simple loading features to more complex folded and faulted structures. A hypothetical model has been proposed which relates the type of deformational features found in recent sediments from an ice impacted area to the process of ice gouging. The deformational structures observed in the sediments from Harrison Bay were compared to deformational features found in sediments from ancient environments that are known to have had floating ice present. The results indicate that structures found in the modern environment bear a remarkable similarity to structures found in the ancient environments, and that the structures found in the ancient environments are believed to have been caused by the process of ice gouging.