红岩
The Norwich Crag Formation is a marginal facies of the thicker, much better developed sedimentary sequence in the southern North Sea basin. It outcrops in the eastern half of the counties of Norfolk and Suffolk, and is also represented in Essex and Hertfordshire. Geological field relationships show that it rests with discontinuity on the Red Crag Formation and oversteps in other places onto the Coralline Crag, the Palaeogene formations and Chalk Group bedrock. It is overlain disconformably by the Wroxham Crag Formation, and unconformably by the Kesgrave Catchment Subgroup and Mid Pleistocene glacigenic deposits.