APPLYING THE “PLAY” CONCEPT TO ARCHETYPAL CANADIAN SURFICIAL AQUIFERS

The Geological Survey of Canada (GSC) is currently assessing 30 key Canadian aquifers. This represents a small fraction of the aquifers in Canada. Consequently, there is a need for an aquifer classification that can synthesize information on archetypal surficial aquifers. A simple glacial landform or depositional facies model approach does not suffice, because it fails to integrate the complexity of geographic, geological and hydrological controls on the occurrence of aquifers. One approach is the play concept used in the petroleum industry that involves the three components of source, reservoir, and trap (seal). These concepts have direct parallels to aquifers, namely as hydrology, aquifer geology, and geology of confining units. Data for characterization of the play type may be drawn form legacy, and archival sources along with project specific data collection of data on sediment facies, physical properties, geophysical signatures, geochemistry, hydrochemistry, hydrology, etc within a basin analysis framework. Characterization of these three elements is used to formulate aquifer play types common to the surficial (glacial) sediment cover of Canada, and in doing so highlight the benefits and drawbacks inherent with development of each. The aquifer play type is identified by a compound play term based on landforms and/or stratigraphic architecture followed by depositional environment (e.g. moraine, subaqueous fan). In the embryonic application of the play concept to aquifer studies completed primarily by the GSC, but also described in the broader literature, we provide a cursory review of play types for archetypal surficial aquifers within the list of 30 key Canadian Aquifers. Specifically, four play types are reviewed: i) bedrock interface buried valleys, ii) sediment hosted buried valleys, iii) stratified moraines, iv) glacilacustrine / glacimarine basin eskers.

Application of the play concept to hydrogeology offers the same opportunity as in the hydrocarbon context, of providing an analogue for aquifers that may have received less study but have similar characteristics. The play concept can also provide a framework to discuss groundwater extraction from different areas based on similar aquifer and hydraulic conditions.