The BGS Lexicon of Named Rock Units — Result Details
Lower Lincolnshire Limestone Member
| Computer Code: | LLL | Preferred Map Code: | LLL |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Bajocian Age (JB) — Bajocian Age (JB) | ||
| Lithological Description: | Limestones, dominated by low-energy calcilutite, and peloidal wackestone and packstone. Commonly includes sandy limestone or calcareous sandstone in basal part (locally known as Collyweston Slate) and contains substantial units of mudstone, particularly from the Lincoln area northwards. | ||
| Definition of Lower Boundary: | Quasi-conformable or more or less disconformable contact with sandstones and mudstones of the underlying Grantham Formation or, where the latter is absent (mainly in the north), ferruginous sandstone of the Northampton Sand Formation, or mudstone of Lias Group, overlain by limestone or sandy limestone of the Lower Lincolnshire Limestone Member. | ||
| Definition of Upper Boundary: | Disconformable, commonly channelled contact between calcilutites, wackestones and packstones below and the high energy ooidal limestones of the overlying Upper Lincolnshire Limestone Member. Near the northern limit only, disconformable contact with ferruginous sandy calcareous sediments of the Hunstanton Formation (Cretaceous). | ||
| Thickness: | 0 to c. 20 m (south Lincolnshire). | ||
| Geographical Limits: | Essentially as for the Lincolnshire Limestone Formation, ie, Market Weighton area (where overstepped by Cretaceous, Chalk Group, Hunstanton Formation) [probably] to the Kettering-Peterborough area (where overstepped by the Rutland Formation). Locally (or perhaps more generally) cut out by the Upper Lincolnshire Limestone south of Stamford. Extent in subcrop uncertain but probably more or less as for the Lincolnshire Limestone Formation, ie, onshore areas of the northern part of the East Midland Shelf. | ||
| Parent Unit: | Lincolnshire Limestone Formation (LL) | ||
| Previous Name(s): | Kirton Cementstones Member plus Santon Oolite Member plus Raventhorpe Beds Member [Obsolete Name and Code: Use LLL]
(-2906)
Cleatham Limestone (CML) Ellerker Limestone (ELL) Lower Lincolnshire Limestone [Obsolete Name and Code: Use LLL] (*330) Kirton Cementstone Beds (KCM) Raventhorpe Beds (RVB) Kirton Cementstone Beds (Knoll-Reef) (KCMK) Santon Oolite (SNO) Scawby Limestone (SYL) Lower Lincolnshire Limestone plus Middle Lincolnshire Limestone [Obsolete Name and Code: Use LLL] (-4163) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Metheringham Quarry. Metheringham and Blankney members (see Ashton, 1980). | ||
| Reference Section | Ketton Quarry, Rutland, near Stamford, Lincolnshire. About 7.5m of uppermost beds of Member seen. Cox and Sumbler, 2002. 279 (detailed measured section by Sumbler, 2003). | ||
| Reference Section | Braceby Long Hollow Quarry. Blankney Member (see Ashton, 1980). | ||
| Type Section | Sproxton Quarry, Leicestershire (designated as Type Section herein). Showing lowest 17m of Member; uppermost few metres not seen. Cox and Sumbler, 2002. 287, Ashton, 1980 and detailed measured section by Sumbler, 2003. | ||
| Partial Type Section | Leadenham Quarry (see Sumbler et al., 1990). Sproxton to Lincoln members of Ashton, 1980. | ||
| Reference(s): | |||
| Kent, P E. 1966. A review of the correlation of the Lincolnshire Limestone (Inferior Oolite). Transactions of the Leicester Literary and Philosophical Society, Vol.60, 57-69. | |||
| Ashton, M. 1980. The stratigraphy of the Lincolnshire Limestone Formation (Bajocian) in Lincolnshire and Rutland (Leicestershire). Proceedings of the Geologists' Association, Vol. 91, 203-224. | |||
| Cox, B M, and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] | |||
| Gaunt, G D, Fletcher, T P and Wood, C J. 1992. Geology of the country around Kingston upon Hull and Brigg. Memoir of the British Geological Survey, sheets 80 and 89 (England and Wales). 172pp. | |||
| Berridge, N G, Pattison, J, Samuel, M D A, Brandon, A, Howard, A S, Pharaoh, T C, and Riley, N J. 1999. Geology of the Grantham district. Memoir of the British Geological Survey, sheet 127 (England and Wales). | |||
| Barron, A J M, Lott, G K, and Riding, J B. 2012. Stratigraphical framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf. British Geological Survey Research Report RR/11/06. | |||
| Hollingworth, S E and Taylor, J H, 1951. The Northampton Sand Ironstone, Stratigraphy, Structure and Reserves. Memoir of the Geological Survey of Great Britain. | |||
| Sumbler, M G. 2003. In Leicestershire and Rutland Geodiversity Action Plan. British Geological Survey Commissioned Research Report CR/04/063N. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E127 E158 E143 E157 E170 E171 E185 E142 | |||