Age of Rotational Landslides in the Cypress Hills, Alberta-Saskatchewan

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>The topography of the west block of the Cypress Hills indicates that fluvial dissection of the plateaux and subsequent rotational landsliding of valley sides have been the dominant Quaternary geomorphic processes. This paper presents a preliminary chronology of rotational landslides based on the relative ages of 17 landslides and on 3 absolute dates. Four indices of relative age were used: organic content in Ah and B soil horizons, the size and coverage of lichens and weathering rind thickness on boulders exposed by landsliding, and the concavity and gradient of gullies in landslide debris, One landslide occurred in 1965. Organic materials collected from buried soil horizons beneath depressions on 3 other landslides were radiocarbon dated at 1235 ± 105, 1635 ± 105 and 7259 ± 165 yrs. BP. Microscopic analysis of the organic material revealed that the oldest sample was contaminated with older carbon. Cluster analysis of the relative age data in conjunction with 3 acceptable absolute dates suggests that the landslides under study have occurred during late Holocene time.</jats:p>

Age of landslides along the Grande Rivière de la Baleine estuary, eastern coast of Hudson Bay, Québec (Canada)

“…One major problem in reconstructing landslide activity over a long period of time arises from availability of datable material and use of suitable dating techniques. In a recent paper, Goulden & Sauchyn (1986) reviewed briefly some techniques that have been used to date landslides. Some provide absolute dates (radiocarbon dating), while others yield relative dates (morphological parameters, weathering-rind thickness, size and coverage of lichens on boulders exposed by landsliding, soil properties).…”

Nature, Origin, and Age Relationships of Landscape Complexes in Southwestern Saskatchewan

“…Goulden and Sauchyn (1986) demonstrated valley widening continued during the Holocene as radiocarbon dates of about 6.2 ka BP (S-2629), 1.7 ka BP (S-2630) and 1.2 ka BP (S-2631) 1 were obtained from beneath landslides along the plateau margins. The fresh scar of a recent landslide can been seen at Police Point just inside the Alberta boundary.…”