The BGS Lexicon of Named Rock Units — Result Details
Baggy Sandstones Formation
| Computer Code: | BYS | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Famennian Age (DA) — Famennian Age (DA) | ||
| Lithological Description: | Interbedded brown and grey fine-grained sandstones, siltstones and greenish-grey shaly mudstones with thicker buff, fine- and medium-grained feldspathic and micaceous sugary sandstones. | ||
| Definition of Lower Boundary: | The unit is conformable with the underlying Upcott Slates. The Baggy Sandstones sequence of grey and buff, fine- to medium-grained, thickly-bedded and massive sandstones, marked by local ferruginous staining is in sharp contact of cream, buff, green, grey and purple slates and silty slates of the underlying Upcott Slates. | ||
| Definition of Upper Boundary: | Conformable with the overlying Pilton Shales, though no sharp formation boundary lines can be traced. The top of the Baggy Sanstones, characterised by thickly-bedded and medium-grained sugary sandstones with partings of thinly-bedded micaceous sandstone, passes transitionally into the Pilton Shales, seen typically as shales and siltstones with placed at the top of the highest of the fine- to medium-grained sugary sandstones of the Baggy Sandstone. | ||
| Thickness: | Up to 450 m. | ||
| Geographical Limits: | Around Barnstaple in North Devon, the outcrop runs east to west between the coast and inland, near to Dulverton. | ||
| Parent Unit: | Exmoor Group (EXM) | ||
| Previous Name(s): | Marwood Beds [Obsolete Name and Code: Use BYS]
(-100)
Baggy And Marwood Beds [Obsolete Name And Code: Use BYS] (BMB) Baggy and Marwood Slates [Obsolete Name and Code: Use BYS] (-1410) Baggy Beds [Obsolete Name and Code: Use BYS] (-1411) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Baggy Point, North Devon, where the foreshore and cliffs expose the base and top of the formation and much of the 450 m thickness. Edmonds and others, 1979. Part of the middle of the Baggy Sandstones appears to have been cut-out by faulting. | ||
| Reference(s): | |||
| Edmonds, E A, Williams, B J and Taylor, R T. 1979. Geology of Bideford and Lundy Island. Memoir of the Geological Survey of Great Britain, Sheets 292 with 275, 276, 291, and part of 308 (England and Wales). | |||
| Edmonds, E A, Whittaker, A, and Williams, B J. 1985. Geology of the country around Ilfracombe and Barnstaple. Memoir of the British Geological Survey, Sheets 277 and 293 (England and Wales). | |||
| Ussher, W A E. 1879. On the geology of parts of Devon and west Somerset, north of South Molton and Dulverton. Procedings of the Somerset Archaeological and Natural History Society. | |||
| Goldring, R. 1971. Shallow-water sedimentation as illustrated in the Upper Devonian Baggy Beds. Memoir of the Geological Society of London. No.5. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E293 E292 E294 | |||