The BGS Lexicon of Named Rock Units — Result Details
Fernham Sand Member
| Computer Code: | FHMS | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Aptian Age (KP) — Aptian Age (KP) | ||
| Lithological Description: | Reddish-brown, ferruginous, cross-bedded, shell-fragmental, medium- to coarse-grained, clean sandstone. There are scattered pebbles, bands of conglomeratic grit and minor horizons of mudstone. | ||
| Definition of Lower Boundary: | Unconformable contact with the underlying Baulking Sand Member, marked by the upward facies change from the predominantly mudstone facies of the upper part of the Baulking Sand Member, to the ferruginous sandy facies of the Fernham Sand Member. | ||
| Definition of Upper Boundary: | Not seen. The Fernham Sand Member occurs as hill-cappings in the Baulking area. The top of the member is locally defined by the depth of the present-day weathered zone. | ||
| Thickness: | At least 24 m in the Furze Hill Borehole SU29SE/16 [2905 9281] (Poole et al., 1971). | ||
| Geographical Limits: | Area around Little Coxwell and Fernham, Oxfordshire. | ||
| Parent Unit: | Faringdon Sand Formation (FDNS) | ||
| Previous Name(s): | Division 4 (sands with chert and ironstone) [Obsolete Name and Code: Use FHMS]
(-3402)
Furze Hill Sandstone Formation [Obsolete Name and Code: Use FHMS] (-3403) Ferruginous Sands and Sandstones [Obsolete Name and Code: Use FHMS] (-2801) Red Sands of Uffington [Obsolete Name and Code: Use FHMS] (-248) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | In the vicinity of Furze Hill [SU 29 92] and Fernham [SU 293 919], Oxfordshire. | ||
| Reference Section | Furze Hill Borehole SU29SE/16 [2905 9281] and boreholes F10 (SU29SE/5 [2982 9242]), F12 (SU29SE/7 [2925 9288]) and F13 (SU29SE/8 [2950 9305]) described in Poole et al. (1971), all located near Fernham, Oxfordshire. The Furze Hill Borehole contains the thickest development of the Fernham Sand Member. | ||
| Reference(s): | |||
| Hopson, P M, Wilkinson, I P and Woods, M A. 2008. A stratigraphical framework for the Lower Cretaceous of England. British Geological Survey. British Geological Survey Research Report, RR/08/03. | |||
| Casey, R, 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, Vol.3, 487-621. | |||
| Poole, E G, and Kelk, B. 1971. Calcium montmorillonite (fuller's earth in the Lower Greensand of the Baulking area, Berkshire. Institute of Geological Sciences Report 71/4. | |||
| Meyer, C J A. 1864. Three days at Faringdon. Geologist, Vol.7, 5-11. | |||
| Arkell, W J. 1947. The Geology of Oxford. 267pp. (Oxford: Clarendon Press.) | |||
| Wilkinson, I P. 2006. The Holostratigraphy of the Albian Stage (Lower Cretaceous) of the United Kingdom and its continental shelf. British Geological Survey Research Report, RR/06/01. | |||
| Poole, E G, Kelk, B, Bain J A, and Morgan, D J. 1971. Calcium montmorillonite (fuller's earth) in the Lower Greensand of the Fernham area, Berkshire. Report of the Institute of Geological Sciences, 71/12, 64pp. | |||
| Rawson, P F, Curry, D, Dilley, F C, Hancock, J M, Kennedy, W J, Neale, J W, Wood, C J and Worrsam, B C. 1978. A correlation of Cretaceous rocks in the British Isles. Geological Society of London, Special Report No.9. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||