|Title||Surficial geology mapping, shallow gas, granular resources and diamond potential in northern British Columbia and Alberta|
Smith, I R; Paulen, R C; Ferbey, T; Hickin, A S; Levson, V M; Bednarski, J; Pawlowicz, J G; Nicoll, T J;
Ahmad, J; Schmitt, D; Rokosh, D; Kowalchuk, C; Ward, B; Fenton, M M; Trommelen, M; Tarplee, M; Demchuk, T; Kerr, B|
|Source||CANQUA 2005 Conference, program and abstracts
; 2005 p. A69-A70|
|Alt Series||Earth Sciences Sector, Contribution Series 2004454|
|Meeting||CANQUA 2005 Conference; Winnipeg, Manitoba; CA; 2005|
|Program||Northern Resources Development Program |
|Program||Targeted Geoscience Initiative (TGI-2), 2003-2005 |
|Program||Alberta Geological Survey, Funding Program |
|Program||British Columbia Ministry of Energy, Mines and Petroleum Resources, Funding Program
A four-year collaborative and multi-disciplinary project between the Alberta Geological Survey (AGS), the British Columbia Ministry of Energy and Mines (BCMEM) and the Geological
Survey of Canada (GSC) was initiated in 2003. The objective of this project is to produce geoscience information in support of exploration for aggregate resources, diamonds, and shallow gas reservoirs in Quaternary/Paleogene (Tertiary) sediments in
northwest Alberta and northeast British Columbia. The project was created under the GSC's Northern Development Program with some financial support from the Targeted Geoscience Initiative-2.
Surficial geology maps are being produced for the study
area to 1) reconstruct ice-flow history, patterns of deglaciation, and glacial lake history as an aid for mineral exploration, and 2) identify regions with potential granular resources and underlain by permafrost for infrastructure development
dominantly related to the oil and gas industries. Preliminary results indicate that the Laurentide Ice Sheet advanced to the west and southwest over the region and that the pattern of retreat was influenced by topography. Glacial Lake Hay developed
over a vast region of northwest Alberta and northeast British Columbia following the blocking of the eastward drainage by the retreating ice sheet.
Since the mid 1990's, near the hamlet of Rainbow Lake, Alberta, shallow gas has been
extracted from shallow horizons located in unconsolidated sediments. Shallow gas is present in buried porous fluvial and glaciofluvial sediments (sand and gravel) within paleovalleys eroded into producing bedrock horizons. Gas has migrated from the
bedrock source into the sediments which are capped by a succession of clayey till and glacial lake deposits. Bedrock topography and drift thickness maps produced by the AGS and the BCMEM are used for the identification of buried valleys and
exploration targets for shallow gas reservoirs. Also, these paleovalleys are of interest because they are associated with well site blow-outs, artesian aquifers and seismic interpretation problems. In collaboration with the University of Alberta, a
10 km long seismic survey was conducted across a buried valley identified from a bedrock topography map. In addition, an electrical resistivity survey was conducted along the same survey line. Preliminary interpretation of both datasets indicate the
presence of gas at 50 to 100 m depth within a broad channel incised into bedrock and dominantly infilled by Quaternary sediments.
As part of this project, bulk glacial sediments are collected and processed for kimberlite indicator minerals (KIMs)
to evaluate the potential of the region for diamond exploration. In January 2005, the BCMEM reported the presence of KIMs in glaciofluvial sediments from northeast British Columbia including purple pyrope, yellowish eclogitic garnet, Cr-diopside,
olivine, ilmenite and spinel. The provenance of these minerals remains to be identified. A number of areas were staked immediately after the report was released.
Granular resources are in high demand in northeast British Columbia for road
improvements and for developing new access routes. Important new aggregate sources have been identified in the region using a variety of subsurface data sets (seismic shot-hole, water well, conductor pipe and gamma logs) airborne electro-magnetic
surveys, high resolution LiDAR data and surficial geology mapping. The new aggregate resources represent a direct savings to BCMEM of over $15 million to date.