Stone Run

A stone run (called also stone river, stone stream or stone sea) is a conspicuous rock landform, result of the erosion of particular rock varieties caused by myriad freezing-thawing cycles taking place in periglacial conditions during the last Ice Age. The actual formation of stone runs involved no less than five processes: weathering, solifluction, frost heaving, frost sorting, and washing. The stone runs are essentially different from moraines, rock glaciers, and rock flows or other rock phenomena involving the actual flow of rock blocks under stress that is sufficient to break down the cement or to cause crushing of the angularities and points of the boulders. By contrast, the stone run boulders are fixed quite stably, providing for safer climbing and crossing of the run.

Stone runs are accumulations of boulders with no finer material between them. In the Falklands, they occur on slopes of between 1 and 10 degrees, and are the product of mass-movement and stone sorting during past periods of cold climate. They everywhere occur in association with poorly-sorted, clay-rich solifluction deposits