| Norwich Crag Formation | |
|---|---|
| Stratigraphic range: Early Pleistocene ~ | |
 Easton Wood cliffs, Covehithe, Suffolk | |
| Type | Geological formation |
| Unit of | Crag Group |
| Sub-units | Chillesford Sand member, Chillesford Clay Member, Easton Bavents Clay Member, Westleton Beds Member, Sidestrand Member |
| Underlies | Wroxham Crag Formation, Kesgrave Catchment Subgroup, Mid Pleistocene glacigenic deposits |
| Overlies | Red Crag Formation, Coralline Crag Formation |
| Thickness | about 70 metres |
| Lithology | |
| Primary | Sand |
| Other | Gravel, clay, silt |
| Location | |
| Region | East Anglia |
| Country |  United Kingdom |
| Type section | |
| Named for | Bramerton, Norwich |
| Named by | Clement Reid |
| Year defined | 1890 |
| Coordinates | 52°12′53″N 1°24′58″E / 52.2147°N 1.4160°E |
The Norwich Crag Formation is a stratigraphic unit of the British Pleistocene Epoch. It is the second youngest unit of the Crag Group, a sequence of four geological formations spanning the Pliocene to Lower Pleistocene transition in East Anglia. It was deposited between approximately 2.4 and 1.8 million years ago, during the Gelasian Stage.
The Norwich Crag 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. It was deposited in a near-shore environment, and comprises a range of sands, silty clays and flint-rich gravels representing various transgressive and regressive marine episodes. It rests in some places on the Red Crag Formation and in others unconformably on Coralline Crag, Palaeogene formations and Chalk Group bedrock. It is overlain by the Wroxham Crag Formation, and unconformably by the Kesgrave Catchment Subgroup (part of the Dunwich Group) and Mid Pleistocene glacigenic deposits.
Norwich Crag fossil fauna and flora have been studied since the 19th century for information about environmental conditions during the early Pleistocene. They provide evidence for a general climatic cooling trend from the Pliocene to the Pleistocene.