GEUS have successfully completed a major field campaign in South-East Greenland - one of the lesser-known and under-explored regions of Greenland. Despite challenging sea ice and weather conditions at the start of the season, the expedition was successful with significant and interesting preliminary findings.
The project is co-financed by GEUS and the Bureau of Minerals and Petroleum (BMP) of the Government of Greenland, and its objective is to gain a better understanding of the geology and economic potential of the region, and to collect data to attract the mineral exploration industry. The program in South-East Greenland was initiated in 2009 with geological reconnaissance work and systematic regional geochemistry of stream sediments and surface water. The work in the craton part of SE Greenland continues in 2012, and in 2013 GEUS will continue similar field work slightly to the north in the Palaeoproterozoic Ammassalik Mobile Belt.
Twenty geologists and students, including collaborative researchers from University of Aarhus, University of Copenhagen (including the Geological Museum), University of Stellenbosch and Centre of Exploration Targeting at University of Western Australia participated in the fieldwork. Furthermore, a research team from the Greenland Institute of Natural Resources studying polar bears, and two exploration companies who hold mineral licenses in the area, used GEUS logistical platform in the area. GEUS worked in teams of two to four geologists out of small tent camps, or from a ship-based base-camp on the expedition vessel M/V Fox, with the aid of a helicopter and zodiac dinghies.
Field campaign highlights
The North Atlantic craton in South-East Greenland is dominated by orthogneisses, mafic granulite, belts and slivers of paragneiss, mafic and ultramafic units. The region is structurally complex with at least seven deformation events and regional metamorphism up to granulite facies, partial melting and syn- to late-orogenic magmatism of the Archean Skjoldungen Alkaline province. Younger, brittle deformation and greenschist facies hydrothermal systems are also present. The focus and some of the findings in 2011 include:
- Detailed mapping and sampling to characterize the rock units and establish a tectono-metamorphic stratigraphy.
- Nickel mineralization, found during reconnaissance in 2009, has been confirmed and extended.
- Sulphide mineralisations in garnet-bearing, possibly metasedimentary, gneiss units have been investigated.
- New undeformed iron-rich alkaline intrusions have been discovered.
- Potassic alteration in fault zones has been observed. These zones also carry carbonate-dominated veins, dykes and breccia zones.
- Late brittle to brittle-ductile deformation zones with hydrothermal alteration characterized by K-feldspar, epidote and chlorite occasionally contain quartz- and carbonate-quartz veins that are sulphide-bearing.
- Structural and metamorphic investigations, including studying brittle structures related to possible late sedimentary basin development offshore.
- Investigations and sampling of intrusives of the Archaean Skjoldungen Alkaline Province, including the Singertât carbonatite-ijolite complex. Preliminary results indicate that an added magmatic component to surrounding gneisses during migmatisation might be more wide-spread than previously recognized.
Further information
For more information about the project in South-East Greenland and the results, please contact Karen Hanghøj (kha@geus.dk) or Bo Møller Stensgaard (bmst@geus.dk) at GEUS