The objective of this report was to compile selected assessment file report information from ultramafic rock occurrences in Alberta into a single, usable document for government, industry and the public.
Compiled information in this report includes
1) the location of 50 ultramafic rock occurrences in Alberta, which include:
• Buffalo Head Hills field: 33 kimberlites on the southeastern flanks of the Buffalo Head Hills, north-central Alberta (there are actually 38 reported pipes, but 5 locations are still unknown);
• Birch Mountains field: 8 kimberlites in the Birch Mountains, northeastern Alberta;
• Mountain Lake field: 2 alkaline ultrabasic diatremes directly north of Mountain Lake, northwestern Alberta;
• Sweet Grass Instrusives: 7 hypabyssal (dykes, plugs) intrusions in the Milk River area of southeastern Alberta (including 1 hypabyssal diorite porphyry, Black Coulee);
2) a brief overview of the exploration history of each ultramafic rock occurrence field or cluster;
3) diamond content results for 31 diamondiferous kimberlites (29 in Buffalo Head Hills and 2 in the Birch Mountains) and from the Black Butte minette in southern Alberta;
4) 157 drill logs from drillholes completed on 29 diatremes; and
5) 30 ground geophysical maps from surveys over 44 diatremes and the results of 1 aeromagnetic survey flown in the vicinity of the Sweet Grass Intrusives.
Assessment file reports and selected publication references that were used during this compilation on Alberta ultramafic rock occurrences include:
• Buffalo Head Hills: Skelton and Bursey (1998, 1999)
• Birch Mountains: Aravanis (1999)
• Mountain Lake: Wood and Williams (1994), Leckie et al. (1997); Wood et al. (1998)
• Sweet Grass Intrusives: Kjarsgaard (1994), Ash et al. (1995), Ross et al. (1997)
In addition to assessment file reports, information was culled from various news releases, particularly for diamond contents (Ashton Mining of Canada Inc., 1997a, 1997b, 1997c, 1997d, 1998, 1999a, 1999b, 2001).