Sedimentological Characteristics and Classification of Depositional Processes and Deposits in the Glacial Environment,
Abstract
Existing classifications for deposits in the glacial environment are inadequate and inconsistent. Deposits should be classified both descriptively and genetically; adequate descriptive classifications already exist. A major problem for previous genetic classifications has been that glacial deposition and the resulting deposits' properties were poorly understood. On the basis of three criteria-sediment source, uniqueness to the glacial environment, and preservation of glacier-derived properties-deposits in the glacial environment result from either of two groups of processes: primary or secondary. Primary processes release the debris of the glacier directly and form deposits that may bear properties related to the glacier and its mechanics. Their deposits are classified genetically as till and are the only deposits indicative of glaciation. In contrast, secondary processes mobilize, rework, transport and resediment debris and deposits in the glacial environment. They develop new, nonglacial properties in their deposits, while destroying or substantially modifying glacier-derived properties. Interpretation of their properties may provide information on the depositional are classified genetically according to the depositional process just as they are in other sedimentary environments. This genetic classification differs from previous classifications in that not all diamictons deposited in the glacial environment are classified as till; it is based strictly on process-related criteria. The origin of properties of glacial deposits in relation to the glacier's mechanics and environment must be recognized if the mechanisms and depositional processes of former glaciers are to be precisely understood. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA113261
Entities
People
- Daniel E. Lawson
Organizations
- Cold Regions Research and Engineering Laboratory