ANNUAL REPORT 2003
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Mineral resources and Greenland mapping |
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Initiatives for extended diamond exploration
With support from the Bureau of Minerals and Petroleum, GEUS continued its efforts to increase the interest of the mining industry in diamond exploration in Greenland. During the summer of 2003, geologists worked on mapping kimberlitic rocks which may be diamondiferous. At three selected sites, samples weighing tonnes were extracted from kimberlite dykes with a view to testing their diamond content and study the distribution, magnetic properties and chemistry of kimberlites. A comprehensive programme for dating kimberlites from West Greenland has been initiated in cooperation with University of Alberta, Edmonton. In addition the landscape between Maniitsoq and Kangerlussuaq was surveyed in order to map the distribution of large plains, valleys, and more alpine landscape elements. The surveys are to contribute to understanding why, and how much bedrock has been eroded by water, wind, and ice over millions of years. This work was conducted in cooperation with Stockholm University. Finally, a DVD was published with a comprehensive collection of existing data from the diamond exploration of the mining industry in West Greenland over 35 years and GEUS' own data collected in many years of geological research. |
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Geological maps of thousands of square kilometres
During the summer of 2003, GEUS completed a three-year mapping campaign in the area between Sisimiut and Disko Bay with a view to preparing new detailed geological maps which are in high demand in the mining industry. The coupling of the large amounts of geological data and the drawing of the new maps are in full swing. The summer field work also included studies of the fractures in the terrain between Sisimiut to Aassiaat in order to understand the development of a large fault structure that continues beyond the coast in this area, and has helped in the formation of large sediment basins that may contain oil deposits. Over the year, a geological map has also been published on a scale of 1:1 000 000 of the Caledonian fold belt in East Greenland between 70°N-82°N. The map, which covers an area of almost six times that of Denmark, is based on a compilation of five previously published maps on the scale of 1:500 000, and it collates geological knowledge from more than 30 years of mapping work in the remote East Greenland. Finally, a map was published with more than 130 km of geological profiles of the basalts on the Disko Island in West Greenland. The profiles contain detailed information about the individual lava flows and document the build-up of parts of the basalt province of West Greenland. |
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Two mountain ranges become one
New geological surveys show that about two billion years ago in West Greenland a large unbroken mountain range was formed which measured up to the Himalayas in width. The formation of the mountain range took place when two ancient continents collided, and today a deep cut in the now long eroded fold belt can be seen from the eastern part of Canada to Greenland and possibly all the way to Scandinavia. It has long been believed that central West Greenland was built up of two different mountain ranges, the so-called Nagssugtoqides and the Rinkian fold belt. However, new studies of folds and other structures in the rocks in the Greenlandic mountains and new datings of the rocks now indicate clearly that the entire bedrock area between Kangerlussuaq and Upernavik constitutes the roots of one giant ancient mountain range. The results shed new light over the early movements of the Earth's lithosphere plates, and the new large mountain range in West Green-land can be directly correlated with the Rae-Hearne province in eastern Canada, while the correlation to the east under the Inland Ice is uncertain. This work, which is supported by the Carlsberg Foundation, was carried out in close cooperation with research institutions in the USA, Australia and the UK. |
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Gold for Greenland
We did it! The first gold bars were extracted from Greenland's first gold mine in the Nalunaq area in South Greenland, and some of the gold will be used to produce the rings for the wedding of the Danish Crown Prince and his fiancée. GEUS is involved in the production of a geological description of the gold deposit. This work is being carried out together with the Bureau of Minerals and Petroleum and the mining company, Nalunaq Gold Mine A/S, which has the license for the region. However, GEUS has also focused on minerals in the Nuuk area where chances of finding gold are good. Here, several Archaean greenstone belts are found which look like similar rock formations in other parts of the world with large finds of gold and nickel. This is documented in a comprehensive report from GEUS which sums up the known mineralisations and the geological development of the Nuuk area together with a presentation and interpretation of the existing geophysical and geochemical data. The report also contains a DVD with several reports on mining companies' previous activities in the area and a large amount of extra geophysical and geochemical data and geological field maps from GEUS' archives. The initiative for the report was taken by the Bureau of Minerals and Petroleum with a view to attracting the mining industry to the area. |
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The North Sea as supplier of raw materials
The North Sea contains other resources than oil and gas. Denmark needs raw materials for building and construction work, and the mineral resources in the seabed are now in play as a supplement to the resources on land. In 2003, GEUS worked with producing maps of the seabed sediments in the coastal parts of the North Sea between Hanstholm and Blåvands Huk, and determination of the raw materials potential in the area has started. The mapping builds on several years' collection of seismic data and data showing the surface and composition of the seabed. The mapping has been carried out in cooperation with the Royal Danish Navy, the Royal Danish Administration of Navigation and Hydrography and the Danish Coastal Authority, and the results are used by the Danish Forest and Nature Agency which has administrative responsibility of regulating the extraction of raw materials. |
