Cromer Forest Bed

The Cromer Forest-bed Formation, sometimes known as the Cromer Forest Bed, is a geological formation in Norfolk, England. It consists of river gravels, estuary and floodplain sediments predominantly silt, sand, and muds as well as peat along the coast of northern Norfolk.^[1] The Cromer Forest Bed itself varies in age from about 2 to 0.5 million years ago, from the Early Pleistocene to early Middle Pleistocene,^[2] though the most fossiliferous strata, such as the West Runton Freshwater Bed date to towards the end of deposition during the early Middle Pleistocene. The fossiliferous West Runton Freshwater Bed is the type locality for the Cromerian Stage of the early Middle Pleistocene between 0.8 and 0.5 million years ago.^[3] Some fossils from the Cromer Forest Bed likely come from Early Pleistocene layers, though many finds are found out of stratigraphic context.^[4]

Cromer Forest-bed Formation
Stratigraphic range: Early Pleistocene - Middle Pleistocene 2–0.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Cromer Forest-bed Formation exposed at the base of the West Runton Cliffs
Type	Geological formation
Unit of	Dunwich Group
Sub-units	Sheringham Member, Runton Member, West Runton Member, and Bacton Member
Underlies	Middle Pleistocene glacial deposits
Overlies	Wroxham Crag Formation or unconformity with Chalk Group
Thickness	around 6 metres (20 ft)
Lithology
Primary	sands and silts
Other	peat, mud, silty marl
Location
Coordinates	52.941°N 1.253°E / 52.941; 1.253
Region	Norfolk
Country	England
Type section
Named for	Cromer
Named by	Clement Reid
Location	The coast of North Norfolk from Weybourne to Happisburgh
Year defined	1882
Country	England

It is about 6 metres (20 ft) thick^[1] and is exposed in cliff section near the village of West Runton.

Paleontology and paleobotany

For over a century this formation, named after the local town of Cromer, has been famous for its assemblage of fossil mammal remains, containing the diverse remains of numerous taxa. Species of deer recovered include those of Eucladoceros, Praemegaceros, Megaloceros/Praedama savini, the early moose relative Cervalces latifrons, as well as red deer, fallow deer, and roe deer.^[5] Remains of carnivorans include those of the large lion Panthera fossilis, the sabertooth cat Homotherium, the "European jaguar" Panthera gombaszoegensis the early wolf Canis mosbachensis, cave hyena, brown bear, wildcat (Felis lunensis), and lynx.^[3] The large hippopotamus Hippopotamus antiquus has also been recovered probably from Cromerian aged layers.^[6] The West Runton Mammoth, a largely complete skeleton of the steppe mammoth (Mammuthus trogontherii) is one of the most best preserved finds found in the West Runton Freshwater Bed. Other proboscideans found in the Cromer Forest Bed include those of the earlier mammoth Mammuthus meridionalis, as well as the straight-tusked elephant (Palaeoloxodon antiquus).^[7] The bison Bison schoetensacki has also been found in the Cromer Forest Bed.^[8] A variety of birds are also known from the Cromer Forest Bed.^[9]

Archaeology

The oldest human footprints outside Africa, the Happisburgh footprints as well as handaxes and bison bones with cut marks were also found in layers considered to belong to this deposit near Happisburgh, dated to around 1 million to 780,000 years ago.^[2]

See also

• Cromerian Stage
• Pakefield