The Yellowknife mining camp is one of Canada's major gold mining districts, and one of the best preserved and exposed Archean volcanic belts in North America. The two largest producers in the camp, the Con and Giant mines, have produced more than 5.5 million and 7.1 million ounces of gold respectively (Northern Miner June 19, 2000). The Con Mine poured its first gold bar in 1938 and the Giant Mine commenced production about 10 years later. However, with the recent weakness of the price of gold, diminishing reserves in the camp, and an interest on the part of the mining companies in the camp to develop a comparative understanding of the mineralization at the two operating mines, and to support research in the belt, the Yellowknife camp became a prime candidate for an EXTECH-type study.

EXTECH III originated in response to a formal request to the GSC for scientific research assistance in the Yellowknife Greenstone Belt (YGB) from the Government of the Northwest Territories, Miramar Mines Inc., and Royal Oak Mines Ltd, at the Yellowknife Forum in November 1997. Scientific objectives and priorities for the project were determined by a group of university, industry and government geologists at a public Needs Assessment Workshop in November, 1998 in Yellowknife. This workshop resulted in the identification of themes and priority objectives (see below). The project officially commenced with a public call for proposals in the spring of 1999. The proposals were reviewed by the Advisory Committee based on the agreed objectives and priorities, and funding announcements were made in June 1999. A similar process was followed for work in Year 2 (2000-2001). Twenty-six projects were funded in the first year, many of them feasibility or scoping projects. A smaller selection of projects (sixteen) are being funded in Year 2 based on results of the first year of research and updated priorities. The Yellowknife EXTECH project is profiled for completion in March, 2003, with its final year (2002-2003) planned mainly for integration and write-up of results and preparation of a final publication.

The Yellowknife EXTECH project involves collaboration among earth scientists from the Geological Survey of Canada (GSC), the Government of the Northwest Territories(GNWT), the Department of Indian and Northern Affairs (DIAND),private industry and professors and students from seven Canadian universities. GNWT and DIAND support is through the C.S. Lord Northern Geoscience Centre in Yellowknife. The project is managed by the EXTECH III Advisory Committee, with one member from each of DIAND, GNWT, GSC and 3 industry representatives, on the committee.

The GSC's EXTECH III supporting partners include Miramar Mining Inc.(Con and Giant mines), several prospectors in Yellowknife, DIAND, the Government of the Northwest Territories, and NSERC through participating university researchers. Within Natural Resources Canada, the EXTECH project benefits from and contributes to the mandates of the Earth Sciences Sector, (Mineral Resources Division, Continental Geoscience Division, and Terrain Sciences Division of the Geological Survey of Canada), and Minerals and Metals Sector.

In addition to direct funding of projects within their respective organizations, the three government agencies involved in the Yellowknife EXTECH agreed to pool resources into a joint fund for additional projects through a proposal-driven system. Pooled resources totaled $190K in 1999-2000 and will total approximately $310K in 2000-01. Significant human resources are contributed by project partners in addition to operational dollars. Starting this year, Year 2 of the project, the Yellowknife EXTECH project has also been supplemented with significant funding support from the Targeted Geoscience Initiative. Themes and priority objectives of the Yellowknife EXTECH, as determined by consultation with researchers, partners and stakeholders, are as follows:

• Bedrock Mapping and Geochronology:
  to develop a better understanding of the regional geological, structural and geochronological setting of the Yellowknife Belt and associated gold mineralization; and to develop a regional framework for a metallogenetic understanding of the Belt;

• Surficial mapping and geochemistry:
  to develop an understanding of the surficial geology of the Yellowknife area, to determine the applicability of geochemical exploration techniques in the area, and develop a model of the geochemical response for these deposits;

• Geophysics:
  to acquire and compile a regional geophysical database for the Yellowknife area, and to determine the geophysical characteristics of mineralized rock, and develop a model of geophysical survey response of gold-rich rock;

• Mineral deposit studies:
  to develop a well-constrained genetic model for the Yellowknife gold deposits, and refine our general understanding of Archean shear-zone hosted deposits; to develop a regional metallogenic understanding of the Yellowknife Belt and surrounding basin, and to develop an improved exploration model for Archean shear-zone hosted gold deposits, and;

• Data integration and delivery:
  to develop an integrated 3D GIS/structural model of the deposits in the belt; to integrate all of the data and interpretations generated by this research project into a spatially-referenced digital database (GIS); and, to establish delivery mechanisms for dissemination and publication of results, data and interpretation, in a timely manner.

Further details of the Yellowknife EXTECH III, including copies of abstracts from the 1999 Yellowknife Forum presentations, are available at the EXTECH III web site.

Annual publication and or dissemination of information at the NWT Geoscience Forum is a requirement of EXTECH support. In addition, interim results may be published in GSC Current Research or DIAND EG reports. A yearly workshop of EXTECH participants and interested stakeholders is held at the Yellowknife Forum, and a field meeting is planned for Summer 2001 to aid in dissemination of research results to the exploration community. The final results of this project will be published in a joint GSC-GNWT-DIAND report to permit all participants to communicate their results. Journal papers will also be encouraged.

Results of the first complete year of research are encouraging, including: anomalous gold grain counts, and diamond indicator minerals were identified in preliminary surficial mapping and till sampling work (Kerr, Smith and others); preliminary testing of biogeochemical prospecting techniques yielded encouraging results for their application in exploration for gold and base metals in this terrain (Nickerson); integration of previous metamorphic grade indications, and new mapping of metamorphic isograds is providing new tools for interpreting regional structures (Thompson); and, detailed comparative structural observations underground at both Con and Giant mines is leading to a better understanding of structural controls on mineralization and the possible genetic relationship between the two mines (Siddorn).

Contacts: 'Lyn Anglin (GSC); Jackie Cusveller and Deb Archibald (GNWT), Carolyn Relf (DIAND).