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TitleAn update of kimberlite and base metal indicator minerals in glacial sediments from the Zama Lake region, northwest Alberta (NTS 84L and 84M)
AuthorPaulen, R C; Plouffe, A; Smith, I R
SourceProgram with abstracts, seventeenth annual Calgary Mining Forum, "New mines, prospects & advances"; 2008 p. 35
Alt SeriesEarth Sciences Sector, Contribution Series 20070617
MeetingCalgary Mining Forum; Calgary; CA; April 15-18, 2008
NTS84L; 84M
AreaZama Lake; Bistcho Lake
Lat/Long WENS-120.0000 -118.0000 60.0000 58.0000
Subjectseconomic geology; surficial geology/geomorphology; glacial deposits; tills; till analyses; till geochemistry; kimberlites; diamond; sphalerite; indicator minerals; dispersal patterns
LinksCanadian Database of Geochemical Surveys, downloadable files
LinksBanque de données de levés géochimiques du Canada, fichiers téléchargeables
AbstractThis presentation highlights the results of indicator minerals recovered from glacial sediment samples collected in northwest Alberta (NTS map sheets 84L and M). The objective of this sampling program, part of a collaborative surficial mapping initiative undertaken by the Alberta Geological Survey and the Geological Survey of Canada, was to evaluate the potential of this region to host diamond-bearing kimberlite and other mineral deposits. Results to-date have been jointly published as Alberta Geological Survey Special Reports 77, 87 and 96 and Geological Survey of Canada Open Files 5121, 5545 and 5692, respectively. These joint reports identify the presence of low concentrations of kimberlite indicator minerals and high concentrations of sand-sized sphalerite grains in till from northwest Alberta and highlighting the potential for the area to contain primary bedrock-hosted zinc deposits.

Kimberlite indicator minerals were detected in low concentrations throughout the two NTS map sheets, with rare higher concentrations (3 to 9 grains) clustered in the Zama Lake - Zama City area. The source, proximal or distal, is unknown and remains to be identified. However, of particular significance, and the focus of recent collaborative research, is the discovery of a sphalerite dispersal train in the south-central sector of the Bistcho Lake (NTS 84M) and north central sector of the Zama Lake (NTS 84L) map sheets. Dark grey to black, angular, brittle grains of sphalerite, with rare grains of orange to honey sphalerite, were found in high concentrations (>100 grains) in nine bulk till samples (~30 kg) including the highest concentration of 1047 sphalerite grains (normalized to 30 kg sample weight) in one till sample. Background concentrations in local till are zero grains. The sphalerite grains exhibit pristine morphology with angular to sub-angular edges. The dispersal train footprint extends over an area of approximately 4000 km2. One to four grains of galena were reported in eight of the till samples obtained from this anomalous region. The galena grains are also angular to sub-angular. The bedrock source of the sphalerite remains unknown; additional chemical and isotopic analyses are underway to help elucidate its origin. The geographically restricted presence of samples with sphalerite grains in the regional sample set (n=70) may point to undiscovered sedimentary hosted zinc deposits in this region and, therefore, represents new opportunities for mineral exploration.