Arctic Basalt, Axel Heiberg Island, Canada
Some of the northernmost terrestrial volcanic rock outcrops are situated on Axel Heiberg Island in the high arctic of Canada. Being relatively resistent to erosion they form prominent cliffs, some of which show remarkably well developped columnar basalt. These lavas are part of the Albian (late Early Cretaceous) age Strand Fiord Formation. At that geological time North America, Greenland and Eurasia were still connected as one single landmass. Volcanic activity may have been related to the opening of a new ocean basin in the early Tertiary. Volcanc depostits in northern Canada are possibly related to similar ones in Franz Josephs Land and Svalbard, forming the "High Arctic Large Igneous Province" (Tarduno 1998).
Basaltic deposits at Dragon Head Mountain on the north shore of Expedition Fjord are more than 200 metres thick. They were tilted during the orogeny which formed the mountains of Axel Heiberg.
Careful inspection of the lower right of this photo reveals a sill entering the series of strata, which then turns upwards, thus becoming a dike, which finally feeds one of the lava beds near the centre of the image.
Spectacular columnar basalt as seen from the bascamp near Crusoe Glacier at Expedition Fjord, Axel Heiberg Island. The rocks in the far background are sandstones.
A Twin Otter aeroplane is silhouetted against spectacular Bastion Ridge. Whereas the lower strata are sandstones, its uppermost part consists of basaltic deposits, some of which show columnar forms.
|Photos taken by Jürg Alean during a glaciological research expedition to Axel Heiberg.|