GLACIALLY-STRIATED BOULDER - Whitby, Yorkshire

Sandsend, near Whitby, Yorkshire

As an ice sheet moves across the land it grinds up and picks up pieces of the rocks over which it passed. Most of these rock fragments are crushed or carried along with the ice but larger ones are sometimes lodged at the bed of the thick ice sheet. The ice dragged other fragments over these, grinding and scratching them.

Glacially-transported boulders therefore often have scratches or striations over their surfaces, providing conclusive evidence of the former presence of ice sheets or glaciers.

This small boulder was found on the Yorkshire coast in glacial till (boulder clay) in the cliffs, which was laid down by an ice sheet. It is a very fine example of a glacially-striated boulder with striations on both sides.

Please note: This item weighs more than 3 kilograms. The photos are taken using oblique lighting to make the striations easier to see.