The BGS Lexicon of Named Rock Units — Result Details
Exeter Group
| Computer Code: | EXE | Preferred Map Code: | EXG |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Cisuralian Epoch (PLC) — Cisuralian Epoch (PLC) | ||
| Lithological Description: | Component formations are predominantly breccia, with subordinate sandstone. All formations are alluvial fan deposits. | ||
| Definition of Lower Boundary: | Basal formations in Crediton Trough (Cadbury Breccia, Upton Formation, Bow Breccia, Knowle Sandstone) rest unconformably on Bude or Crackington formations. Around and south-west of Exeter, basal formations (Dawlish Sandstone, Whipton Formation, Knowle Sandstone) rest unconformably on Crackington Formation. See definitions of component formations. | ||
| Definition of Upper Boundary: | Unconformably overlain by Aylesbeare Mudstone Group. | ||
| Thickness: | At least 700m. | ||
| Geographical Limits: | From Torbay in the south, north through Newton Abbot to Exeter; all New Red Sandstone strata in the Crediton Trough and probably the Tiverton Trough. | ||
| Parent Unit: | New Red Sandstone Supergroup (NRS) | ||
| Previous Name(s): | Lower New Red [Obsolete Name and Code: Use EXE]
(-4643)
Marginal deposits [Obsolete Name and Code: Use EXE] (-2794) Lower Sandstone And Breccia (-897) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | Group named from the city of Exeter, Devon. | ||
| Reference(s): | |||
| Ussher, W A E. 1906. Chapter on Geology. "In" Victoria History of the Counties of England (Devonshire), p.1-48. | |||
| Henson, M R, 1972. The form of the Permo-Triassic Basin in south-east Devon. Proceedings of the Ussher Society, Vol.3, p.447-457. | |||
| Ussher, W A E. 1902. The Geology of the country around Exeter. Memoir of the Geological Survey of Great Britain, Sheet 325. (England and Wales). | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E310 E311 E308 E355 E356 E307 E350 | |||