Minturn circles: a new glacial feature

• Published in: Canadian Journal of Earth Sciences
• Main Author: Appel, Peter W. Uitterdijk
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1996
• Subjects: General Earth and Planetary Sciences; Arctic; Greenland; Inglefield Land; Ice; Ice cap; Inglefield land; permafrost
• Online Access: http://dx.doi.org/10.1139/e96-109; http://www.nrcresearchpress.com/doi/pdf/10.1139/e96-109

In Inglefield Land, northwest Greenland, a new glacial feature has been found, consisting of well-defined circles and rings ranging in size from a few metres to about 80 m in diameter and in colour from black to pink. More than 300 circles and rings are known. They are composed of slightly rounded boulders, cobbles, and pebbles frequently overgrown with black lichen. The circles and rings consist of syenite that was picked up by the inland ice under permafrost conditions by a melting–refreezing process. The syenite till was subsequently transported by the inland ice across Ingiefield Land and deposited in cut-off meanders of melt-water streams on the surface of the stagnant ice cap. During melting of the inland ice the circles and rings were deposited on a peneplain consisting of boulder fields and outcrops of Precambrian and Cambrian rocks. These circles are probably quite common features in high-arctic regions, but their recognition requires special conditions.