Jackson, Ian. Northumberland Rocks — 50 extraordinary rocky places that tell the story of the Northumberland landscape. Newcastle upon Tyne : Northern Heritage, 2021. The richly illustrated and accessible book series of Northumberland, Cumbria and Durham Rocks are available to purchase from Northern Heritage.
26 Saltpan Rocks
Theme: Earthquakes and folded rocks
Location
Just to the east of Scremerston you can park beside the coast road at Cocklawburn Beach and walk north.
Description
On the foreshore, near Scremerston, limestone rock has been bent into one incredible tight fold and several arches (anticlines).
In the limestone, which has been polished by the sea, there are many thousands of fossils of ancient sea shells, called brachiopods, and corals.
The limestones, which alternate with sandstones, shales and thin coals, were deposited in a sub-tropical clear, coral sea in Carboniferous times 330 million years ago. The rocks were bent and folded when Britain and northern Europe were part of the building of an enormous mountain chain which began about 300 million years ago.
The changing rock sequence — limestones, followed by shales (mudstones), then sandstones, seatearths (fossil soils), and thin coals — is repeated many times. Geologists have concluded that this tells a story of rising and falling sea level as the Earth’s ice caps grew and then melted millions of years ago. In many ways that’s like the period of Earth’s history we live in today.
The sand dunes nearby are calcareous because of the many shell fragments. Plants include purple milk-vetch, burnet rose, viper’s bugloss and bloody crane’s-bill (including a pale pink variety). On the backshore is Scots lovage, which reaches its southern-most east coast limit in north Northumberland. Shorebirds include purple sandpiper, turnstone and oystercatcher.