In the Northleach area a massive freestone member similar to the Taynton Stone and known as the Farmington Freestone is locally developed near the top of the formation. The thickness varies between 4 m and nearly 10 m. The zonal index ammonite Procerites progracilis occurs rarely. acuminata, but the best-known fossils are vertebrate remains including fragments of pterodactyl, dinosaurs, crocodiles and primitive mammals. Characteristic bivalves include Gervillella ovata, Vaugonia impressa and P. The fauna is well known mainly due to the long continued collecting of the slates. The bed was dug out and exposed to frost action which split the rock along the closely spaced relatively permeable laminae formed of ooliths. The ‘Slates’ were obtained from the Slate Bed or ‘Pendle’, an impersistent bed, 0.6 m or less in thickness, of oolitic sandy limestones near the base of the member. They were formerly worked for roofing tiles and known as ‘Cotswold Slates’. Commonly, the main facies consists of fissile, sandy, shelly, and oolitic limestones comprising the Eyford Member. They are most completely seen in the Hampen Cutting of the now disused Cheltenham–Banbury railway line east of Cheltenham. The Stonesfield Slate Beds comprise varied passage strata, 4 to 10 m thick, between the Lower Fuller’s Earth and Taynton Stone north-east of Cirencester. They are well exposed at Hornsleasow (formerly Snowshill) Quarry, 4 km west-south-west of Bourton-on-the Water, where a total of 1.7 m of beds includes a coral bed containing abundant well-preserved compound corals such as Cyathopora, Isastraea and Thamnastraea. Overlying the Chipping Norton Limestone north of Condicote in the north Cotswolds, there are up to 2 m of shelly clays known as the Sharp’s Hill Formation, which may include many corals, brachiopods, bivalves and gastropods. Ammonites are rare, but those that occur suggest that the Chipping Norton Limestone falls within the zigzag Zone. The bivalve Plagiostoma cardiiformis occurs in most exposures, while obscure plant remains and occasional saurian bones of Megalosaurus and the crocodile-like Teleosaurus and Steneosaurus are not infrequently found. Decalcification has in some cases reduced it to sand.įossils are not common. Typically, it consists of buff, hard, rather sandy and splintery oolite, often cross-bedded, containing minute specks of lignite elsewhere the beds are flaggy and have been worked in the past for flagstones. This formation exhibits considerable lithological variation. The Chipping Norton Limestone, which may include the underlying Hook Nor- ton Limestone of Oxfordshire, reaches a maximum thickness of about 12 m in the Hornsleasow (formerly Snowshill) Quarry, about 4 km west-south-west of Bourton-on-the-Water. Its lower part persists for some distance, but is absent north of Condicote and east of the Moreton ‘Axis’ where it is replaced by the Chipping Norton Limestone and the Sharp’s Hill Formation. The Lower Fuller’s Earth diminishes in thickness due to lateral passage of its upper part into the Stonesfield Slate Beds between Minchinhampton and Cirencester ( P948984). (P948984) Cirencester–North Cotswolds Lower Fuller’s Earth The section between Kingscote and Cold Ashton is adapted from Cave, 1977, fig. Several of the constituent formations, notably the Taynton Limestone Formation and the Forest Marble Formation are notable for their fossil content, including those of dinosaurs and pterosaurs and some of the earliest mammals.Diagrammatic section to show lateral variation in the Great Oolite Group in the Cotswolds. It is also present at depth in the Weald and Wessex Basins, as well as offshore. It is exposed at the surface as a variably thick belt extending roughly NE-SW from the coast of Dorset up to the Humber. It consists of a complex set of marine deposits primarily mudstone and bioclastic ooidal and fine grained limestone, deposited in nearshore to shelf settings. The Great Oolite Group is a Middle Jurassic stratigraphic unit that outcrops in southern England. Cornbrash Formation, Chipping Norton Limestone, Sharp's Hill Formation, Taynton Limestone Formation, Forest Marble Formation, Hampen Formation, White Limestone Formation, Rutland Formation, Blisworth Limestone, Blisworth Clay Formation, Chalfield Oolite Formation, Corsham Limestone Formation, Athelstan Oolite Formation, Horsehay Sand Formation, Tresham Rock Formation
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