One enjoyable aspect of school is the opportunity to explore new ideas which keeps your field of study fresh. Now that may seem like a funny statement, if only for its obviousness alone. Isn’t that what school is for? Well, sure, but in the grind of labs, term papers, presentations, and exams, the experience of discovery for its own sake is often put on the backburner for other things such as good grades and late-night coffee runs.

Geomorphology is a subfield of geology that I’ve not had much exposure to in the past few years, and I regret that. Not only is it useful for seeing first hand the way wind, water, and ice enact weathering and erosion to sculpt the land in a plethora of unique features to better our understanding as geoscientists, it just so happens to be interesting, too. For example, just this evening I was working on a chapter summary assignment on periglacial environments – high latitude or high altitude environments that are not permanently glaciated, but where seasonal ices and permafrost features act as a major control on landforms – and stumbled across the idea of nivation.

Simply stated, nivation is a feature of the periglacial environment where small snow patches not large enough to be considered glaciers act as a control on weathering and erosion (Fig. 1). Weathering occurs at the margin of the snow bank, and meltwater acts as the erosianl agent. It’s a slow and subtle process, but effective, forming so-called ‘nivation hollows’ in the side of hills.

Fig. 1. Idealized model of a nivation hollow in the side of a hill. Note the erosional alluvial fan at the base of the snowpatch. Adapted from Thorn and Hall (2002).

The reason this struck so pointedly was because it reminded me of the sort of features I saw while hiking the Bald Hills this summer near Jasper, Alberta:

 

(Nivation hollow with snow patch on the northeast face.)

Granted, it’s minimal in extent compared to the model in Figure 1, but it’s at the proper elevation for a periglacial setting above the treeline at approximately 2225 m. Secondly, keep in mind this photo was taken in early August with snow cover at a minimum. I would like to visit this site in late spring once the seasonal snow cover has melted. I can easily imagine the process of nivation going on; field confirmation would be the icing on the cake.

Additionally, just down slope is an impressive talus field:

(Looking east, downslope on a periglacial talus field. Nivation hollow to the right, Maligne Lake in the background.)

I cannot provide a date on this feature (I suspect the last glacial maximum) but I think it provides a pretty good case for a periglacial environment. In any event, it’s a veritable playground for any geomorphologist. I think I can even provide evidence for tors:

 

(Tors near the ‘summit’ of the Bald Hills at 2300 m – note the vertical and horizontal joints between close-packed, yet separate weathered blocks of rock, esp. near centre of photo.) 

References

Thorn, C.E., and Hall, K. (2002), Nivation and cryoplanation: the case for scrutiny and integration. Progress in Physical Geography, vol. 26, no. 4, p. 533-550

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