Kellaways

Middle Jurassic (Callovian)

Lithology
Mudstone, grey, commonly silici-silty or silici-sandy, with (predominantly in the upper part) beds of generally calcareous siltstone and sandstone.

Upper Boundary
Generally sharp but conformable junction between sandstone/siltstone in upper part of formation with mudstone of overlying Oxford Clay Formation.

Lower Boundary
Generally sharp, conformable or non-sequential junction with bioclastic limestone of underlying Cornbrash Formation, overlain by grey mudstone, commonly a thin unit of shell-fragmental, more or less sandy mudstone occurs at base (where this is more strongly cemented it is included in the Cornbrash Formation).

Representative Sites
South Cerney Railway Cutting

Information on lithology and boundaries taken from the British Geological Survey Lexicon of Named Rock Units