GeoGraph - photograph every grid square

Unconformity at Rifle Butts Quarry

White, grey and red chalk of the Cretacious period rests on top of a brownish Jurassic mudrock, the time gap between the two being some 80 million years. Whilst the Wolds are typical chalk country, there is a thin strip of Jurassic limestones and sandstones along the western edge, underlying the chalk at this point and often resulting in a spring line. The Jurassic outcrop links the Lincolnshire Edge with the Howardian Hills further north.