Periglacial features on Isla de los Estados, Tierra del Fuego, Argentina

LJUNG, K.; PONCE, J. F.

Cordoba, Argentina

Congreso; III Congreso Argentino de Cuaternario y Geomorfología.; 2006

Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cordoba

Active sorted circles and stone stripes are reported for the first time from Isla de los Estados, a remote island in Tierra del Fuego, southernmost Argentina. The features were found above the tree-line at 500 m a.s.l. on an exposed ridge in the eastern part of the island. Stone stripes are app. 15 cm across with a fine-grained centre and bordered by a coarse rim. Sorted circles are app. 10 cm in diameter with a slightly elevated fine-grained centre bordered by a coarser rim. The features are most likely active and formed by repeated freeze-thaw cycles. The features were found in an exposed setting where insulation by winter snow is limited.