Mechanically-formed Grikes in Sandstone

Abstract

IN the Lower Old Red Sandstone of the west of Caithness I have noticed an appearance which recalls the grikes due to erosion of which Mr. Carus-Wilson writes in NATURE of May 1. It is seen in the platform of marine denudation in a minor inlet on the north coast at the village of Reay, eleven miles west of Thurso. The dip of the rocks varies from 10° to 30°, averaging 17°, 10° west of north, and the low scarps, lying transverse to the axis of the bay, run down to the sea, giving rise to the tiny inlets locally known as “ports.” or “porties.”