ANNUAL REPORT 2001
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Mineral resources and Greenland mapping |
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Mineral resources as a principal industry
The summer of 2001 saw the launch of extensive exploration of mineral resources and geological mapping of the area from Maniitsoq to Disko Bay in West Greenland. This work forms part of the efforts to make the exploitation of mineral resources a principal industry in Greenland. The mapping and dating of rocks in the area was started with a view to identifying its general geological conditions, which is essential when assessing the presence of minerals. The mapping activities are conducted jointly by GEUS and geologists from the USA, England and Poland. They also follow up on geochemical and geophysical investigations of previous years. Areas with interesting element discoveries in river sediments and particularly significant magnetic conditions were studied to find out if they are caused by the presence of minerals in the rocks. The studies focused on gold, silver, copper and zinc and the occurrence of potentially diamondiferous source rocks, the so-called kimberlites. Fieldwork led to the discovery of new occurrences of kimberlite dykes and boulders, and the GEUS kimberlite discovery database now contains more than 600 locations in Greenland. Raw material investigations were also on the agenda in North-West Greenland and East Greenland. Geochemical samples were collected and ore geological reconnaissance carried out in an area of 4,300 km2 near Qaanaaq/Thule. And in East Greenland samples and spectral data were collected in the field to follow up on the collection in 2000 of advanced airborne hyperspectral surveys. This type of data has been used successfully in mineral exploration in a number of different environments around the world. A new map sheet on a scale of 1:500,000 of the area north of Mesters Vig was published as a result of investigations in previous years. |
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Geophysics to attract industry
After a year's break, the airborne magnetic surveys of West Greenland were resumed. In connection with Aeromag 2001, during the summer, magnetic data was collected along a linear distance of 70,000 km in the area between Uummannaq and Upernavik. The purpose of the surveys is to increase industry interest in raw materials exploration with regard to both onshore minerals and offshore oil and gas. This work is financed by the Bureau of Minerals and Petroleum, Greenland Home Rule. More than 100 new maps of magnetic conditions providing new information on geological underground structures have subsequently been produced. The digital data and maps were released in March 2002. To conclude the AEM Greenland programme, a CD-ROM with electromagnetic and magnetic data collected from the air during the period from 1994 to 1998 was also issued. It includes maps from six areas in West, North and East Greenland with an accompanying report describing the data and providing an introduction to the geology of the areas. |
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New tool for mineral and environmental studies
A new comprehensive geochemical atlas of South and West Greenland was issued on CD-ROM. This atlas is based on chemical analyses from more than 7,000 samples of river sediments collected by GEUS from 1977 to 1998. It contains maps of more than 43 chemical elements, a gamma radiation map and five maps of kimberlite indicator minerals found in river sediments. The atlas also contains a geological and a magnetic map. The maps and data are in Oasis Montaj® format on the CD-ROM which also contains a report and bibliography of geochemical studies carried out over many years. |
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Treasures hiding in the sea
Important raw materials for building and construction work in the form of sand, gravel and stone are hidden at the bottom of the sea. With a view to mapping quantities and qualities of the offshore raw materials, for a number of years GEUS has been collecting seismic data and data showing the surface and structure of the North Sea bed. This mapping work has been a joint effort of GEUS, the Danish Navy, the Royal Danish Administration of Navigation and Hydrography and the Danish Coastal Authority. In 2001, GEUS also collected seismic data, scannings of the seabed and sediment data from borings for the Danish Coastal Authority with a view to planning how best to collect sand for coast reclamation. A map of sand thicknesses and movement was prepared for Horns Rev in addition to findings from the Lodbjerg-Blåvandshuk area in Jutland where similar surveys were conducted from 1998 to 2001. These findings are used by the National Forest and Nature Agency, among others, which has the administrative responsibility of regulating the extraction of raw materials in Danish waters. |
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Good clay for tile production
Not all Danish clay types are equally suitable for tile production. GEUS conducted therefore a study of a number of Danish clay types and potential alternatives such as fly ash, which are or can be used for tile production. This work included analyses of the distribution of particle sizes, mineralogy and chemistry and a number of tile-technical analyses of drying and storage processes. Furthermore, efforts have been made to find suitable geophysical methods for brick clay mapping. This work was carried out in collaboration with the National Forest and Nature Agency, the Danish Masonry Center and a consultancy firm and funded by the National Forest and Nature Agency, the county of Ribe and two brickworks. |
