DIMENSION STONES
Prospecting for dimension stones in Greenland

Thomas Rasmussen, in collaboration with RGS 90 A/S, Greenland Resources A/S and the PNASTINA group.

The primary goal of the Greenland dimension stone project is to find high-value natural rock resources which may form the basis for 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 sea, 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 Greenland Resources A/S. In 2001, work was carried out in the regions of Ammassilik, Skjoldungen, South Greenland and West Greenland. In northern Ammassilik, prospecting identified a pale red post-tectonic granite with low fracture density; this granite is attractive because waste production would be low.
Reconnaissance in the Skjoldungen area was focussed on the search for localities with minerals displaying a schiller effect. Such localities were identified though the target minerals occurred in only minor proportions. 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 gneisses.

Follow-up investigations in 2002 involved the collection of large samples (100-250 kg per sample) from West, South and East Greenland. During the follow-up several new localities were visited and sampled. Samples were collected using "gentle" explosives to avoid fracturing. The large samples were cut and polished by RGS 90 A/S and evaluated by the stone industry.
Several of the samples were 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 Eriksfjord Formation, a kakortokite from the Ilímaussaq intrusion, and a flame-structured gneiss from the Nassuttooq area.

In 2003, exploration continued in the Nassuttooq area for additional and potentially better localities of flame-structured gneisses. Ten localities were identified where the flame-structured gneiss showed low fracture density.
Two other rock types of potential interest were also discovered in the Nassuttooq area. In South Greenland, prospecting was focussed on the kakortokite from the Ilímaussq intrusion and the sandstone from the Eriksfjord Formation, where the main focus was to find a red massive sandstone with low fracture density. 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.

In 2004, a group of dimension stone experts from the Nordic countries formed a collaborative group under EU's Northern Periphery Programme called "promotion of natural stone industry in the northern areas" (PNASTINA). In co-operation with the PNASTINA group, the cut and polished samples from Greenland have been promoted to the industry during exhibitions and articles in stone magazines.
A web page with the prospected localities are in progress.

The future plan is to continue the prospecting in Greenland and promote the knowledge we have collected so far.
The project is financed by Greenland Resources A/S and the Northern Periphery Programme INTERREG III B 2000-2006.

References
Rasmussen T. 2004: Unikke sten fra Grønland. Tidsskriftet 'Tegl', september 2004/ 3.
Rasmussen T. 2003: Preliminary report on prospecting for high quality aggregates in South Greenland 2002. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2003/ 10, 20 pp.
Rasmussen T. 2003: Dimension stone prospecting in West, South and East Greenland 2002. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2003/ 8 , 60 pp.
Rasmussen T. 2002: Preliminary report on dimension stones and aggregates: field observations in West, South and East Greenland 2002. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2002/ 106 , 55 pp.
Kalvig P., Knudsen C. og Rasmussen T. 2002: Potentialer for facadesten og skærver i Grønland. Afrapportering af felt- og laboratorieundersøgelser 2001. Danmarks og Grønlands Geologiske Undersøgelse Rapport 2002/ 11 , 104 pp

Figure 1. Locality map.

Figure 2. Preparing a 200-kg sample.

Figure 3. Large sample brought on board Søkongen.

Figure 4. Polished sample.

Figure 5. Polished sample.