Depositional Environments

The traverse from Siccar Point to Cove Harbour crosses progressively higher levels of rocks of Upper Devonian and Lower Carboniferous age, deposited after the closure of the Iapetus ocean. The initial sediments were deposited by braided streams crossing an arid landscape, but subject to seasonal rains. Later, swamp environments were established. They led to the formation of thin coals. The swamps were near to sea level and periodic subsidence led to inundation by the sea and development of marine sediments. This is summarised in the cartoon below: