Aggregate potential maps provide guidelines for testing, evaluating and managing aggregate resources within a defined area. The maps provide first approximation estimates of broad, regional aggregate distribution and are suitable for use by municipal and land use planners as well as the aggregate industry.
In 1996, a survey was initiated in the Shushwap and Okanagan areas of southeastern British Columbia, where expansion of population has stressed existing aggregate resources. The study area comprises sixteen 1:50,000-scale map sheets covering the western halves of NTS sheets 82E and 82L. The area forms a corridor 80 km wide and 200 km long stretching from Shushwap Lake south to Osoyoos and the US border.
Fieldwork during 1996 and 1997, combined with air-photo interpretation, identified 308 pits in the study area. Each pit has been accurately located, by hand-held GPS or from published NTS maps, and its host landform type determined. Preliminary results suggest that glaciofluvial deposits, located mainly in and along the low-lying valleys, host 80% of the aggregate pits in the study area. Of these, glaciofluvial fans, terraces and kame terraces account for 75% of the pits. Fluvial sediments (e.g. fans and deltas) form only thin deposits of unconsolidated material and host less than 9% of the pits.
Within the Okanagan area, 3400 individual areas (polygons) have been assessed for hosting potential natural aggregate resources. The polygons are based on soil and landform units identified and delineated by Kowall (1986) and Wittneben (1989), with additions and modifications by the authors. Data derived from these polygons has been combined with the pit inventory, water well records and available geotechnical data to produce the final aggregate resource potential maps.
All polygons (220) which host present or historical aggregate pits were separated out and assigned a classification "H". These represent 9.95% of the total area. In the rest of the project area, 274 polygons have been assessed as being of primary, 552 of secondary and 1296 of tertiary potential. These comprise 5.58%, 16.54% and 34.16%, respectively, of the total map area. Remaining polygons (1085) are classified "U" (Unclassified) comprising 33.78% of the total area.
The resulting aggregate potential maps have been released, in digital format only, as:
P.T. Bobrowsky, P.Geo., N.W.D. Massey, P.Geo., and A. Matheson, P.Geo. (1998): Aggregate Resource Potential of the Okanagan Area (NTS 82E(west) and 82L(west)), B.C. Ministry of Energy and Mines, Open File 1998-5.
Available Data & Maps:
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