Corallian GroupName
94857Province: Dorset to Oxfordshire, and North Yorkshire.
Geologic Age: Oxfordian Age
Other: Limestone, sand and sandstone with subsidiary calcareous mudstone, mudstone, silt and siltstone and trace ironstone. Stratified bedrock. Occurs both onshore and offshore. Deposited during the Oxfordian Age (Jurassic Period) (163.5-157.3 Ma BP). Complex succession of interdigitating limestones, marls, sandstones, sands, siltstones, silts, spiculites, mudstones. To c.100m First appearance of medium- or coarse-grained sand above the Oxford Clay Formation. In some areas, this also defines the top of that Formation but elsewhere, there is an intervening silty unit (West Walton Formation). In the Dorset reference area, at the base of the Inconstans Bed (Kimmeridge Clay Formation), which also marks the Oxfordian-Kimmeridgian stage boundary, but elsewhere at the base of the thick mudstone succession that spans that stage boundary (ie Ampthill Clay and equivalents, and Kimmeridge Clay).
Usage: Current name
