Fognam Chalk Quarry is a 3-hectare (7.4-acre) geological Site of Special Scientific Interest west of Upper Lambourn in Berkshire.

[4] The site is private land with no public access.

The formation can be traced from Hertfordshire to Dorset, but the chalk of Berkshire is only about half the thickness seen in other locations as it is thought that it was deposited over an area of relatively higher ground (the Berkshire-Chiltern Shelf, part of the London Platform) and therefore in shallower seas.

This makes correlation with other formations difficult, due to the absence of certain marker beds, although dating from fossils in the quarry, particularly Middle and Upper Turonian ammonites associated with inoceramid bivalve assemblages has been attempted.

[5][6] The chalk from this quarry was used locally to build houses.