Geograph - photograph every grid square

Cliffs of the Cowie red sandstone formation (sedimentary bedrock formed approximately 426 to 431 million years ago in the Silurian Period) face onto a wave-cut platform of interbedded Castle Of Cowie sandstone and siltstone, formed at the same time. In the foreground, much darker rocks of an intrusion of igneous magma, being part of the North Britain Siluro-Devonian calc-alkaline dyke suite: quartz, feldspar and porphyry formed approximately 359 to 444 million years ago in the Devonian and Silurian Periods. All this happened when the land mass that was to become Scotland was south of the equator.