GSC releases kimberlite data for prairie region

The Geological Survey of Canada (GSC) has released kimberlite indicator mineral data for the Canadian prairie region.

According to R.G. Garrett, co-ordinator of the survey, the results confirm that low-density regional sampling can produce meaningful geochemical and indicator mineral patterns.

The sampling was performed in 1991 in preparation for a region-wide indicator and geochemical survey carried out in 1992. Fifty till samples and more than 100 soil samples were collected along transects from south of Winnipeg to Calgary, north of Edmonton and back to Winnipeg. Analyses were completed in June of this year.

An average of two indicator minerals were recovered per sample, including 13 peridotitic garnets (high Mg and Cr), 17 eclogitic garnets (high Ca, Mg and Ti), 62 chrome diopsides (high Cr and Ca, low Na and Fe) and four picroilmenites (high Mg).

Sites south of Brandon and Winnipeg yielded five peridotitic garnets, including a G10 near the town of Reston, Man. The highest chrome diopside concentration was found in the Yorkton-Roblin area. Between Edmonton and Sakatoon, five peridotitic garnets and other minerals may represent long-distance glacial dispersal from the Fort a la Corne camp. Between Weyburn and Assiniboia, chrome diopsides, eclogitic garnets and one peridotitic garnet were recovered. In the Calgary area, results ranging from Gleichen to Ponoka include two peridotitic garnets, two eclogitic garnets and two chrome diopsides.

According to the GSC’s L.H. Thorleifson, the indicator mineral work was based on methods and data recently published by Charles Fipke, John Gurney, Daniel Schulze and others.

The data were released as Open File 2685. The work was performed as a contribution to Mineral Development Agreements in Alberta and Saskatchewan and with the support of the Manitoba mines ministry.

In 1992, till and soil were collected at more than 1,000 sites across 735,000 sq. km of the prairie region. The GSC expects to begin releasing data from these samples later this year.