A reach of Peace River between Fort St. John and Hudson’s Hope flows in a steepsided
valley cut by meltwater and Holocene river flow through Cretaceous shale and
sandstone covered by clay‐rich glaciolacustrine deposits. Numerous landslides occur on the
banks, initiating in both the bedrock and overburden. Following a recently completed local
landslide inventory and the completion of an airborne LiDAR survey, five landslides have
been examined in detail: the Attachie Slide, the Moberly River Slide, the Halfway River Slide,
the Cache Creek Slide and the Tea Creek Slide. Analysis of the five case studies suggests that
most slope movements can be attributed to one of four dominant landslide failure
mechanisms: compound rock slides, compound overburden slides, shallow rapid flow slides,
and earth flows.
Compound slides in bedrock and overburden are morphologically similar. Most have
the character of compound slides, exploiting weak horizontal clay layers found at multiple
levels in both materials. Typically, a sliding surface develops along a bedding plane presheared
to residual friction and connects to a steep main scarp cross cutting the layers of
rock and soil. Frequently this mechanism then repeats successively at multiple levels. The
Cache Creek Slide and Tea Creek Slide are examples of compound slides in bedrock. The
Moberly River Slide and the Attachie Slide are examples of compound slides in overburden.
The toes of the slide deposits often assume the character of earth flow tongues which are
intermittently removed by river erosion. Shallow rapid flow slides, such as the Halfway River
Slide, are also common in the normally consolidated glaciolacustrine silts and clays of
Glacial Lake Peace that overlie the study area. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/42928 |
| Date | 11 1900 |
| Creators | Van Esch, Kristen Johanna Brearley |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | Attribution-NonCommercial-NoDerivatives 4.0 International, http://creativecommons.org/licenses/by-nc-nd/4.0/ |
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