Projekter i kortlægningsafdelingen
Prospecting for Dimension Stones in Greenland

Project leader: Thomas Rasmussen
In co-operation with RGS 90 and Greenland Resources A/S
Financed by Greenland Resources A/S

Dimension stone production There is currently no dimension stone production in Greenland. All other countries with exposed basement rocks have some level of dimension stone production, facilitated by either cheap labour, good technology or high quality and high value natural rock resources. The primary goal of the Greenland dimension stone project is to find high value natural rock resources leading to a sustainable small to medium scale dimension stone production for export. Most of the ice-free areas in Greenland are very well exposed and near the seaway, so the potential for finding high quality and valuable natural rock resources is high.

The project, initiated in 2001, is run in co-operation with and is financed by Greenland Resources A/S. In 2001 work was carried out in the following regions: Ammassilik, Skjoldungen, South and West Greenland. In northern Ammassilik prospecting identified a pale red post-tectonic granite. The fracture density of the granite is low and therefore attractive because waste production would be low. However the colour is simple and as a consequence the locality was abandoned in 2002 as a candidate for dimension stone production. Reconnaissance in the Skjoldungen area was focussed on the search for localities with minerals displaying a schiller effect. These were identified though the target minerals occurred in only minor proportions. When considered with the remoteness of the region the locality is not regarded as viable. In South Greenland an investigation was carried out on the quality of the Rapakivi granites and a pilot investigation in West Greenland focussed on charnockites and flame-structured gneiss. Preparing a 200-kg sample.

Follow-up investigations in 2002 involved the collection of large samples (100-200 kg per sample) from West, South and East Greenland. During the follow-up several new localities were visited and samples taken. Samples were collected using "gentle" explosives to avoid fracturing. The large samples were cut and polished by RGS 90 and evaluated by the stone industry. Several of the samples rated as "ordinary" in appearance or they were too "open" (hairline fractures in single minerals) for high quality production. However three samples attracted interest from the industry; a sandstone from the Eriks Fjord formation, a kakortokite from the Illimaussq intrusion and a flame structured gneiss in the Nassuttooq area.

Large sample brought on board Søkongen. In 2003 exploration continued in the Nassuttooq area for additional and potentially better localities of the flame structured gneiss. Ten localities were identified where the flame-structured gneiss showed a low fracture density. Two other rock types of potential interest were also discovered in the Nassuttooq area; an orthopyroxene gneiss and a quartz-garnet-biotite migmatite. Large samples were collected and the localities evaluated on the basis of fracture density, colour, size and logistic considerations. In South Greenland prospecting was focussed on the kakortokite from the Illimaussq intrusion and the sandstone from the Eriks Fjord formation. Two samples of the kakortokite were collected for further testing. A naujaite from the Illimaussq intrusion was investigated but proved to be too heavily fractured. The main focus in the Eriks Fjord formation was to find a red massive sandstone with low fracture density. During prospecting a green massive quartzite with low fracture density was found and sampled and nearby the red sandstone showed the best fracture density seen thus far.