The Grantham Formation is a geological formation in England, which dates to the Middle Jurassic Aalenian age around 172 million years ago. It is composed of mudstones and sandstone, usually with abundant plant debris. It overlies the preceding Northampton Sand Formation and underlies the following Lincolnshire Limestone.[1]
| Grantham Formation | |
|---|---|
| Stratigraphic range: | |
 Sproxton Quarry, a Reference Section for the Grantham Formation | |
| Type | Geological formation |
| Unit of | Inferior Oolite Group |
| Underlies | Lincolnshire limestone |
| Overlies | Northampton Sand Formation, Whitby Mudstone Formation |
| Thickness | 2 to 5 m, locally 15 m in channels |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone |
| Location | |
| Region | England |
| Country |  UK |
It is found from the Humber estuary to the Kettering/Peterborough area.
References edit
- ^ "The BGS Lexicon of Named Rock Units - Grantham Formation". British Geological Survey. Retrieved 15 November 2017.