Stone Stripes (IMAGE) University of Bern Caption The up to 200 m long, 15 m wide and 2 m deep sorted stone strips on the southern Sanetti Plateau (ca. 3,900 m a.s.l.) were probably formed during the last glacial period under much cooler conditions and can best be explained by a natural sorting of the stones in the course of the cyclic freezing and thawing of the ground. Credit Heinz Veit Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.