Geological Guide to Kings Dyke

Oxford Clay at Kings Dyke Pit

Peterborough is famous for brick making, and at one time had clay pits all around the city. Today only a few remain open, and one of them is this famous pit, 'Kings Dyke Pit'. The remaining pits have now closed and have naturally filled with water. Most of these have been turned into nature reserves, or walkways. Some are currently being filled in, with new housing estates currently being built or have been built.

It is the Oxford Clay that makes an excellent material for bricks. This clay also happens to be extremly rich in fossils. The Oxford Clay has been reclassified and now falls under the Peterborough Formation. It is Mainly brownish-grey, fissile, organic-rich (bituminous) mudstones with shelly fauna dominated by crushed aragonitic ammonites and bivalves, including nuculoid and meleagrinella shell-beds. Subordinate beds of pale-medium grey, blocky mudstone exist with several bands of cementstone nodules/concretions. The basal beds are commonly silty, with Gryphaea-rich shell beds.