Petrogenetic Considerations for the Late Cretaceous Northern Alberta Kimberlite Province (Conference Abstract)
Quaternary Geology of Northern Alberta: Implications for Kimberlite Exploration (Conference Abstract)
September 11, 2012
The geology of Alberta is favourable for discoveries of diamonds because
To September 2003, 48 kimberlitic pipes have been discovered in three separate areas of the northern Alberta kimberlite province:
Birch Mountains field: eight pipes, which includes seven pipes discovered in 1998 by Kennecott Canada Exploration Inc., Montello Resources Ltd. and Redwood Resources Ltd., and one pipe discovered in December 2000 by New Blue Ribbon Resources Ltd.
Location of kimberlites discovered in northern Alberta with anomalous kimberlite-indicator mineral 'trends', which show the potential for future kimberlite discoveries in northern Alberta is high.
Alberta's Diamond Potential
The Buffalo Head Hills area has the highest diamond content results to date. Twenty-six of the 48 pipes are diamondiferous, and at least three of the kimberlites (K14, K91 and K252) contain estimated diamond grades of >11 carats per hundred tones (cpht) with one Buffalo Head Hills pipe (kimberlite K252) having preliminary mini-bulk (22.8 t) sample grades of 55 cpht.
Alberta has a national/international reputation as having tremendous potential for the discovery of an economic diamond deposit, and will have a mine if explorers can discover a favourable combination of:
The Kimberlite-Diamond Connection
Kimberlite is a rock type first categorized over a 100 years ago based on descriptions of the diamond-bearing pipes of Kimberley, South Africa. Kimberlite is characterized as a hybrid, volatile-rich, potassic, ultrabasic igneous rock. Although volumetrically insignificant on a global scale, kimberlite commonly occurs in fields, or clusters, comprising up to 100 individual, steep-sided intrusions.
Kimberlites are only the mechanism by which diamonds are brought to the surface. Diamonds form much earlier than the kimberlite in the diamond stability field at depths of 110 km to 150 km and temperatures of 900°C to 1200°C. Because kimberlites are derived from deep within the earth (>150 km below the surface), they are able to transport mantle and possibly diamonds to the surface.
Kimberlitic rocks are the most important primary source of diamonds and the main rock type in which significant, economically viable diamond deposits capable of sustained profitable mining have been found so far. Economic concentrations of diamonds only occur in about one per cent of known kimberlites worldwide.
Most economic diamond pipes have 'values' of US $500 million to $5 billion, but can be upwards of $75 billion and attain mining life spans ranging from 20 years to more than 100 years. Discovery of an economic diamond deposit in Alberta would produce considerable wealth for the province in jobs, royalties, mining investment and economic spin-offs for companies supplying the mining industry. For example, the Ekati, NT, mine will contribute about CAN $5.1 billion to Canada's GDP and will create between 675 and 1000 jobs (Venture, May 1997).
Alberta, which has been mainly dependent on revenue from the oil and gas sector, has already experienced a dramatic increase in exploration expenditures from diamond seekers. Between 1995 and 2001, mineral exploration companies in Alberta spent a total of CAN $76 million, of which about $61 million, or 80 per cent of expenditures, was related to diamond exploration.
Current kimberlite-related studies at AGS are focused on
Alberta kimberlite core is available for viewing at the Mineral Core Research Facility.