| Titre | Miles of burning sand: Reconstructing dune field activity 150 years after the Palliser Expedition |
| Auteur | Wolfe, S A; Lian, O; Hugenholtz, C H; Bender, D J; Cullen, J R |
| Source | Geological Society of America, Abstracts With Programs 170-3, 2010 p. 1 |
| Liens | Online - En ligne
|
| Année | 2010 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20100138 |
| Réunion | Geological Society of America, Annual Meeting; Denver, Colorado; US; Octobre 31- Novembre 3, 2010 |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; en ligne; numérique |
| Formats | html |
| Province | Alberta |
| Sujets | sables; dépôts éoliens; dunes; végétation; milieu sédimentaire; sédimentologie; Cénozoïque |
| |
| Programme | Impacts des changements climatiques et adaptation dans le secteur des ressources naturelles et d'autres secteurs clés de l'économie, Géosciences de changements climatiques |
| Résumé | (disponible en anglais seulement)
In July of 1859, Captain John Palliser traversed the Middle Sand Hills of southwestern Alberta, Canada, as part of a four-year expedition assessing settlement
opportunities of British North America. Palliser found the sand hills in a highly active state, and his diary reveals the great challenges he and his men faced while travelling through "… miles of burning sand". Today, this dune field is almost
entirely stabilized by vegetation, with only a few minor blowouts totalling about 10 hectares in area. Using historical airphotos of active sand areas and luminescence dating (IRSL on feldspar) of stabilized dunes, we reconstruct the landscape
encountered by Palliser and show that it was at least an order-of-magnitude more active than today. We further define two periods of rapid dune stabilization after the 1880s and the mid-1930s, corresponding to the onset of comparatively moist
conditions following drought. Whereas previous researchers have confirmed that Palliser travelled through the prairies during conditions of drought, we suggest Palliser's observations of the sand hills significantly influenced his perception of the
southern prairies as a region where "there is no timber, the soil is sandy, with little or no admixture of earthy material and the pasture is inferior", and motivated his famous declaration that the area would be "forever comparatively useless". We
further suggest that a drier, colder and possibly windier climate resulted in desert-like conditions in sand hills prior to the 1800s and that climate, coupled with disturbance suppression, has been the main driver of dune field stabilization across
the Canadian prairies. |
| GEOSCAN ID | 286125 |
|
|