The surficial material dataset was developed as part of the Western Economic Partnership Agreement (WEPA) project covering all of NTS 73M, the southern three-quarters of 74D and southeast part of 84A. Part of the dataset was compiled by airphoto interpretations and followed by random ground-truthing by AGS geologists (NTS 73M). The dataset was later merged with other existing surficial geology maps (74D and 84A).
The mapping scheme chosen for the 1:50 000 scale terrain classification is a variant of the scheme used in Alberta Geological Survey Bulletin 57 to map the surficial geology of the Sand River area (Map 178), NTS 73L, directly south of the study area.
In this terrain classification scheme, each map unit includes a component of genesis, morphology and relief. Where available, additional information regarding the properties of the genetic unit was included as a genetic modifier. For example, the map unit 'sMh1' denotes hummocky (h), low relief (1), sandy (s) moraine (M). Genesis of geological material is considered to be the primary component of the map unit thus colours on the map depict differences in genesis. In the above example, the map unit colour would correspond to the legend colour chosen for moraine (M).
An attempt has been made to reclassify the surficial geological units depicted in the surficial geology map of area NTS 74D (Map 148) using this mapping scheme, without significantly changing the polygon shapes of that previous work.