Two new geological maps of Svalbard issued
Map sheet C4G Mosselhalvøya covers the northern end of Ny-Friesland. The bedrock consists almost exclusively of Precambrian basement rocks, apart from a few erosional remains of Early Carboniferous sandstones and some relatively young igneous rocks. A significant fault, the Eolussletta or Veteranen Fault, cross-cuts the area and subdivides it into a high-grade metamorphic, Palaeo- to Mesoproterozoic complex of gneisses and schists to the west and a non-metamorphic, though folded, sedimentary succession of Neoproterozoic age to the east.
The high-grade metamorphic area to the west was mainly mapped by a Swedish research group led by Prof. David Gee in the 1990s, involving among others PhD students Patrick Witt-Nilsson and Fredrik Hellman. At the same time the eastern area was mapped by Lars-Kristian Stølen on behalf of the Norwegian Polar Institute. A number of uncertainties and problems of interpretation meant that the issuing of map was postponed for many years. In the summer of 2010 NPI geologists carried out a survey of the area with the goal to decide what interpretations should be applied.
Map sheet D6G Vaigattbogen covers an area at Hinlopenstretet, the northern part belonging to Ny-Friesland and the southern part to Olav V Land. The area is highly glaciated. The geological record is exposed along the coastal mountains and on a large amount of numataks. The western portion of the map area lies within the structurally complicated Lomfjorden Fault Zone. The bedrock consists of the same non-metamorphic, folded, sedimentary succession of Neoproterozoic age mentioned above for the eastern part of map sheet C4G, and of overlying, flat-lying sedimentary rocks of Carboniferous and Permian age. The latter also form the eastern parts of the map area, where they are not affected by the fault zone. They are slightly eastward inclined and the easternmost parts reach upward into the Triassic. A large granite intrusion, the Newtontoppen Granite, is exposed in the southwest of the map area, while young igneous dykes and sills of dolerite locally occur within the sedimentary successions.
Mapping was mainly carried out by NPI’s geologists in collaboration with Dr. Karsten Piepjohn, BGR Germany, in 2006 (while shorter trips to the area were done also in 2005, 2010 and 2011). During the final compilation of the map participated also Prof. Galen Halverson, Canada, providing valuable data.
Because of the abundance of ice cover in the area a number of uncertainties concerning the structural interpretation of the fault zone remain. Interpretations must take into account the record of the adjacent areas to the north, south and west.
How to order
Both map sheets cost NOK 80.00 and can be ordered directly from the Norwegian Polar Institute.
References:
Elvevold, S. & Dallmann, W.K. (eds) 2011: Geological map Svalbard 1:100 000, sheet C4G Mosselhalvøya. Norsk Polarinstitutt Temakart nr. 47.
Dallmann, W.K., Piepjohn, K., Halverson, G.P., Elvevold, S. & Blomeier, D. 2011: Geological map Svalbard 1:100 000, sheet D6G Vaigattbogen. Norsk Polarinstitutt Temakart nr. 48.