Center for Environmental Policy and Administration

Sampling-surface orientation and clast macrofabric in periglacial colluvium

Author:S.W.S. Millar and F.E. Nelson
Date: 2001
Publication:Earth Surface Processes and Landforms 26 (5): 523-529

To isolate the influence of sampling-surface orientation on the macrofabric of periglacial colluvial deposits, clast orientation measurements were obtained from seven paired horizontal and vertical exposures in turf-banked solifluction lobes on Niwot Ridge, Colorado Front Range. Most samples form moderately strong, upslope-plunging clusters aligned with the local slope orientation. Fabrics obtained from vertical faces were stronger than those from horizontal exposures in six of the pairs. Near-horizontal sampling surfaces yield less biased results than vertical exposures, owing to operator perceptions, procedural difficulties, and the relative thinness of the layer affected by colluvial processes. Sampling procedures must be standardized before comparative studies of colluvium can yield reliable results.


Susan Millar
Center for Environmental Policy and Administration
The Maxwell School, Syracuse University
Revised 05/07/2008 15:16:29