EXTECH IV brings co-op spirit to Athabasca Basin

According to government figures, the amount of nuclear energy used in the production of world electrical power between 1971 and 1990 jumped more than eight times, from 2% to 17%. In 2001, Saskatchewan mines produced 12,520 tonnes of uranium, or about 35% of the world’s supply from mines.

The Athabasca Basin is the premier host for unconformity-type uranium deposits and has an estimated resource of 969.6 million lbs. of U3O8. These deposits are found at or below the basal unconformity of the Basin, where a layer of sandstone about 1 km thick overlies much older gneissic rocks of the Canadian Shield.

While the Athabasca Basin deposits are unparalleled, exploration to find elephants such as the Cigar Lake and McArthur River mines is both costly and time-consuming. It can take between 10 and 15 years to put a discovery into production. In addition, the public geoscience database is not current, as most of the publicly funded science and technology research was completed in the mid-1980s. More recent studies and results have usually been kept confidential.

Discussions to address the problem of an outdated public-domain geoscience database were initiated five years ago following meetings between geologists from industry and Saskatchewan Industry and Resources during a field workshop. As interest grew, other industry, government and academic institutions were brought into the fold, and in April 2000, several stakeholders agreed to fund an exploration science and technology initiative, which became known as EXTECH IV.

The 3-year, $7.5-million EXTECH IV Athabasca uranium multidisciplinary study was funded by the Geological Survey of Canada (Targeted Geoscience Initiative of Earth Sciences Sector, Natural Resources Canada), the Natural Sciences and Engineering Research Council of Canada, the Saskatchewan and Alberta provincial geological surveys, and uranium producers Cameco (cco-t) and Cogema Resources.

This study follows similar EXTECH efforts in the mining camps at Lynn Lake-Snow Lake, Bathurst and Yellowknife. And according to Dr. Charles Jefferson, a research scientist with the Geological Survey of Canada and a co-ordinator of the study, it represents the way of the future. This new co-operative venture involving federal and provincial geological surveys, industry and academic institutions represents “a philosophical change at government geological surveys, which came about, in part, because of downsizing and to reduce overlap between federal and provincial surveys, but also to better serve our clients by pooling our strengths”.

David Thomas, Cameco’s chief geoscientist and co-chair of the EXTECH IV steering committee, remembers how the project started: “Industry certainly was a catalyst for beginning discussions. There had been no regional geoscience initiatives in the basin for more than 20 years, and we felt that by sharing some of our data, good things would happen.”

Cameco and Cogema provided a selection of non-sensitive information for the study from data pertaining to more than 20,000 drill holes in the basin, as well as selected results from a large geophysical database. In addition, both companies provided access to their mining sites in Saskatchewan and fostered staff participation on sub-project teams.

For the past three years, work on EXTECH IV has been ongoing, and preliminary results were recently released; these included a geoscientific database and a series of papers on sub-projects involving a broad range of topics. In all, there were 15 sub-projects, including structural, sedimentological and stratigraphic studies, as well as seismic-reflection, borehole, gravity, gamma-ray and electromagnetic geophysical studies and organic geochemical studies.

New technologies

According to the summary report, the EXTECH IV study contributed to the understanding of the basin’s formation, its stratigraphic and structural framework, and the mineralization and alteration processes found in uranium deposits. It also demonstrated how new, previously untried, exploration technologies can be used to find deeply buried uranium deposits.

For Dr. Jefferson, the greatest surprise of EXTECH IV has been how useful many of the sub-projects have been in providing new tools for uranium exploration. “Over eighty per cent of the sub-projects have contributed to this in a substantial way, and not just from an academic perspective,” he says.

He notes that the borehole geophysical sub-project, which has been the rosetta stone for linking geology with geophysics, has been effective in outlining alteration. The high-resolution seismic sub-project was able to “image” significant fault structures related to mineralized material. The stratigraphy-sedimentology sub-project examined the relationship between growth faults, sandstone depositional sub-basins, and mineralization. This sub-project demonstrated that the growth fault systems were long-lived, contributing to the large deposits found in Saskatchewan.

A novel sub-project on hydrocarbons that are associated with uranium has concluded that this association is coincidental. However, during their research these scientists also documented heat flow associated with growth faults and demonstrated the age of mineralization. Other more tangible benefits included the delineation of a second conductor at the McArthur River mine and increased staking in Alberta’s portion of the Basin (see separate story).

Final reports

With the study completed and preliminary results released, the stakeholders of EXTECH IV are putting together final reports to be published in a special volume. A prominent conclusion is that the EXTECH IV study has helped geoscientists develop a better understanding of how uranium deposits in the Athabasca Basin were formed. They have also strengthened working relationships among industry, government and universities.

While it is too early to tell, there are high expectations that this study will have other positive benefits for the Canadian uranium mining industry and those communities in which it operates. At the very least, with more advanced exploration techniques and a better understanding of uranium deposit formation, exploration companies should be able to target exploration dollars more effectively. This should help facilitate the growth and long-term sustainability of Saskatchewan’s uranium industry, a major employer in the northern part of that province.

The study may have implications beyond the beyond Athabasca, as exploration technologies could be applied to other basins with potential for unconformity-type deposits. The Thelon Basin in the Northwest Territories and Nunavut, the McArthur Basin in northern Australia, basins of the Aldan and Anabar shields of Russia and basins of the Indian Shield all have similar potential for hosting uranium deposits of this type.

Further information and links are on the EXTECH IV web site at www.nrcan.gc.ca/gsc/mrd/extech4/index_e.html

— The author is a Toronto-based freelance writer specializing in mining and investment issues.