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Norber erratic
Source: Wikimedia Commons

Glacial erratics are rocks that differ from the type of rock native to the area in which they are found. They have been carried by glacial ice, often over large distances.[1] Erratics can range in size from pebbles to large boulders. Erratics take their name from the Latin word errare, meaning to wander.

Examples


  • The Great Stone in Stretford, on the south side of the Roman road from Manchester to Chester, is a glacial erratic that was used as a medieval boundary cross and is thought to have been used as a plague stoneHollowed out stones or boulders, relics of a time when plagues spread through the country in medieval times. They hollows were filled with vinegar and placed at or near parish boundaries in attempt to prevent the spread of the disease by disinfecting coins..[2]
  • The Great Stone of Fourstones, at the county border between North Yorkshire and Lancashire,[1] has fifteen steps carved in its side to enable it to be climbed.
  • The Norber erratics in the Yorkshire Dales near Austwick are among England’s finest sets of glacial erratics.[1] More than a hundred sandstone and slate boulders were deposited on the limestone slopes of Ingleborough by glaciers that melted at the end of the last ice age between 12,000 and17,000 years ago. The erratics are scattered on the hillside, the slate boulders at higher levels than the sandstone. The softer limestone beneath them has eroded into the plinths on which they are balanced.[3]
  • Shap granite from Cumbria has been found in Goldsborough Carr in County Durham, 40 kilometres (25 mi) east of where it originated. It is also found in North Yorkshire and on the Yorkshire Coast at Bridlington.[1]

Citations



Bibliography


Emery, Andy. “Glacial Erratics.” Antarctic Glaciers, 2020.
Harland, John, and Thomas Turner Wilkinson. Lancashire Legends, Traditions, Pageants, Sports, &c., with an Appendix Containing a Rare Tract on the Lancashire Witches, &c. &c. Reprint of 1873 edition, Leopold Classic Library, 2016.
Newman, Alan. “Norber Erratics.” Atlas Obscura.