Norber Erratics

A Norber Erratic Boulder, Norber near Austwick in the Yorkshire Dales.
The boulders of dark Silurian greywacke (sandstone) are classic examples of erratic boulders. These huge rocks were carried uphill from Crummack Dale by a mighty glacier during the last Ice Age, and dropped onto the limestone pavement as the ice melted. Since then acid rain has eroded the surrounding limestone, leaving some boulders perched on limestone pedestals.