Ramsholt, Suffolk (TM 298429-TM 297427)
Ramsholt Cliff is an overgrown slope on the north bank of the River Deben. Erosion sporadically exposes small sections of disturbed Coralline Crag and at low tide Coralline Crag material can also be collected on the muddy foreshore beneath the cliff. Up to about 2.9m of Coralline Crag is exposed in the cliff. Unaffected by aragonite dissolution, the Coralline Crag rests unconformably on an undulating surface of London Clay. At the base of the Coralline Crag is a conglomerate called variously the ‘coprolite bed’, ‘nodule bed’ or ‘Suffolk Bone-Bed’. This remanié deposit contains phosphatic nodules, phosphatised bones, and sandstone concretions (‘boxstones’), derived either from the London Clay or, in the case of the boxstones, from Miocene or Pliocene sediments now no longer preserved.
Unconformably overlying the Coralline Crag are Red Crag sediments deposited during a transgression that eroded away an unknown thickness of Coralline Crag. Ramsholt Cliff is unique in being the only current locality showing Red Crag resting directly on the Ramsholt Member of the Coralline Crag.
Adapted from Daley and Balson, 1999.