The national park sits astride the Iapetus suture, the line along which the former Iapetus Ocean closed during the Silurian period as the former micro-continent of Avalonia to … See more

Old Red Sandstone
The late Devonian Stratheden Group is characterised by sandstones with subordinate siltstones and mudstones. A couple of very small areas of these rocks straddle the border to the southwest of The Cheviot See more

The tholeiitic basalt of the Whin Sill was emplaced during early Permian times. The quartz-dolerite was emplaced within lower Carboniferous bedrock in a sheet which extends south and … See more

Glacial legacy
Much of the park is mantled by glacial till from the last i.e. Devensian glaciation. There are also a number of areas of glacio-fluvial sands … See more

Greywackes originating during the Wenlock epoch (428 – 422 Ma bp) of the Silurian Period are assigned to the Riccarton Group and occupy an area either side of the border with Scotland to the north of Byrness. The rocks exposed in the Coquet Head … See more

Sedimentary rocks of Carboniferous age underlie the southern two-thirds of the national park. The oldest of these rocks within the park are assigned to the Inverclyde Group. … See more

Numerous dykes of Palaeogene age cut the sedimentary rocks of the county. The most significant is the Acklington Dyke which running roughly east-southeastwards from … See more