Geology Reference
In-Depth Information
9.8.4. Summary
A number of points summarize the preceding discussion.
First, slopes evolve in periglacial environments primarily through the combined action
of mass movement and running water, and not through “unique” periglacial processes.
Second, a variety of slope forms exist in periglacial environments and none is limited to
periglacial environments. Third, slope form is primarily infl uenced by the lithological
characteristics of the underlying rock. Fourth, the presence or absence of rock moisture,
in determining the type and rate of weathering and weathering removal, is of prime
importance. Fifth, periglacial slope forms exhibit many similarities with slope forms found
in hot arid and semi-arid regions of the world. Sixth, many slopes are best interpreted as
having been inherited from a previous glacial period, and are, therefore, in disequilibrium
with the present cold-climate environment. Seventh, there is no evidence to assume that
slopes evolve more rapidly under periglacial conditions than under non-periglacial
conditions.
ADVANCED READING
Augustinus, P. C., Selby, M. J. (1990). Rock slope development in McMurdo Oasis, Antarctica, and
implications of glacial history.
Geografi ska Annaler
,
72A
, 55-62.
French, H. M., Harry, D. G. (1992). Pediments and cold-climate conditions, Barn Mountains,
unglaciated Northern Yukon, Canada.
Geografi ska Annaler
,
74A
, 145-157.
Harris, C., Lewkowicz, A. G. (2000). An analysis of the stability of thawing slopes, Ellesmere
Island, Nunavut, Canada.
Canadian Geotechnical Journal
,
37
, 449-462.
Iwata, S. (1987). Debris-mantled rectilinear slopes in the western Sor Rondane Mountains, East
Antarctica. Proceedings, NIPR,
Antarctic Geoscience
,
1
, 178-192.
Lewkowicz, A. G., Kokelj, S. V. (2002). Slope sediment yield in arid lowland continuous permafrost
environments, Canadian Arctic Archipelago.
Catena
,
46
, 261-283.
McRoberts, E. C. (1978). Slope stability in cold regions. In: Andersland, O. B., Anderson, D. M.,
eds,
Geotechnical Engineering for Cold Regions
. McGraw-Hill, New York, pp. 363-404.
Rapp, A. (1960). Recent development of mountain slopes in Kärkevagge and surroundings, north-
ern Scandinavia.
Geografi ska Annaler
,
42
, 65-200.
Rapp, A. (1960). Talus slopes and mountain walls in Tempelfjorden, Spitsbergen.
Norsk Polarin-
stitutt Skrifter
,
119
, 96 pp.
DISCUSSION TOPICS
1. What are the mass-wasting processes which operate on slopes in periglacial
environments?
2. How does the presence of frozen or thawing substrate infl uence slope processes?
3. How similar are the slope forms found in the hot and cold semi-arid regions of the
world?
4. How do slopes evolve under cold non-glacial conditions?
5. Is there a periglacial cycle of landscape evolution?
