EXPLORATION 1998 — Industry mines treasures based on GSC findings

A sizable portion of the research completed by the Geological Survey of Canada (GSC) over the past two years continues to be put to practical use by this country’s mining industry.

For example, the Hope Brook gold deposit in southwestern Newfoundland was defined by GSC scientists as belonging to the high-sulphidation type, and sharing similarities with gold deposits in the Carolina Slate belt in the U.S. The research at Hope Brook was partly responsible for renewed activity in the vicinity, including 1,800 new claims.

In the Abitibi region, studies of gold deposits associated with feldspar-rich volcanic intrusive rocks showed that sedimentary rocks preserved along major fault zones provide favorable environments for the deposition of gold.

In the Yukon’s Selwyn basin, recent studies of gold occurrences confirmed that the region is highly prospective for diverse styles of gold mineralization. Several occurrences of carbonate-hosted, disseminated gold were found to be relatively similar to the those of Nevada’s Carlin trend.

And in Brazil, studies co-authored by that country’s geological survey illustrated that widespread gold mineralization occurs in volcanic sequences not usually considered favorable for the concentration of the yellow metal.

Parallels were drawn between the Tapajos region of Brazil and parts of the Churchill geological province in the Northwest Territories.

Other notable GSC findings include the following:

* Airborne geophysical surveying by the GSC contributed to Noranda Exploration’s discovery of the Camel Back massive sulphide deposit in the Bathurst camp of New Brunswick. The survey sparked a wave of claimstaking and renewed interest in the camp.

* A 4-year study of the Kidd Creek base metal deposit near Timmins, Ont., was completed. The research, in which GSC scientists worked with industry, universities and the Ontario government, indicated that the extensive package of high-magnesium and high-silica volcanics found in the deposit’s footwall may typify the deposit.

* The GSC’s National Geoscience Mapping Program (NATMAP) has been studying the Nechako Plateau in central British Columbia since 1995. The team working there has linked crustal extension with igneous activity and hydrothermal copper-gold mineralized systems, identified a volcanic sequence that is the same age and lithology as a gold-bearing unit in northern British Columbia, and dated, for the first time, the molybdenum mineralization of the Endako porphyry belt. The team will wrap up its study in 2000.

NATMAP has also launched the Western Churchill Project, which will focus on areas of high base metal, gold and uranium potential in the Rankin Inlet-Arviat-Baker Lake area of the Northwest Territories. Output from the project, which is a collaboration among several government bodies, exploration companies and Canadian and U.S. universities, will form the geoscience knowledge base for mineral exploration in the area.

Another NATMAP team working in the Northwest Territories has published eight maps covering 70,000 sq. km of the Lac de Gras kimberlite field and the possible transportation corridor northward to Coppermine. A detailed study of the glacial erosion of kimberlites and the mineralogy and geochemistry of glacial sediments eroded from them was completed; improvements in diamond exploration methods are expected to result from this work.