Grantham Formation

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: Aalenian
Sproxton South Quarry - - 702693.jpg
Sproxton Quarry, a Reference Section for the Grantham Formation
TypeGeological formation
Unit ofInferior Oolite Group
UnderliesLincolnshire limestone
OverliesNorthampton Sand Formation, Whitby Mudstone Formation
Thickness2 to 5 m, locally 15 m in channels
Country UK

It is found from the River Humber to the Kettering/Peterborough area.


  1. ^ "The BGS Lexicon of Named Rock Units - Grantham Formation". British Geological Survey. Retrieved 15 November 2017.