CGRG Bibliography of Canadian Geomorphology
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Author : Burns, E.R.; Bentley, L.R.; Hayashi, M.; Grasby, S.E.; and Smith. D.G.
Date : 2006.
Title : A new paradigm for the Paskapoo Aquifer System: Evidence, implications, and modeling.
Publication : Annual Scientific Meeting of the Canadian Geophysical Meeting, May 14-17, 2006. Banff Centre, Banff, Alberta. Abstracts Volume.
Issue :
Page(s) : 22.
Abstract
In his seminal paper, Toth (1962, J. Geophys. Res., 67: 4375-4387) proposed his model of local groundwater flow cells in the Paskapoo Formation in the vicinity of Red Deer, Alberta, Canada. This theory was extended (Toth, 1963, J. Geophys. Res., 68: 4795-4812) to show how flow cells are nested, and that local flow cells may exist while still honoring the regional flow patterns. Toth also showed that the presence of high permeability lenses would result in local departures from the behavior predicted by his model. This model has been the foundation upon which prairie hydrogeology has been based over the past forty years. A new model of the Paskapoo Formation is presented here in which heterogeneity is the norm, rather than an exception that result in local anomalies. This model is based on a geologic model resulting from interpretation of the depositional environment as a fluvial (possibly anastomosing) system that existed in the rapidly subsiding foreland basin associated with the Rocky Mountain orogeny. A principle implication of this model is that the Paskapoo “aquifer” should instead be conceptualized as an aquifer system in which connectivity of highly permeable facies and fractures are of paramount importance. This model is consistent with Toth’s conceptualization of the regional flow structure, but it predicts that the highly complex Paskapoo Formation will produce regional scale anistropic behavior. While we will never have sufficient data to model the system deterministically, the geologic model implies that there is a loose periodicity of connected pathways that may be quantified statistically, allowing the use of stochastic techniques to quantify flow and uncertainty on the regional scale. The proposed model has strong implications for collection and interpretation of data. The model is described, its implications are examined, and several independent sources of evidence are presented to support the new model.
Bibliography of Canadian Geomorphology