Geology Site Account

Site name: Paglesham boulder

Grid reference: TQ 9235 9323

Brief description of site:

Large boulder of ferricrete probably obtained from a local gravel pit. Ferricrete is an iron-cemented flint gravel, formed by the evaporation of groundwater that contains iron compounds.

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Summary of the geological interest

A large boulder of ferricrete (approx 120 x 60 cm in size) sits on the verge on the south side of a surfaced farm track (public footpath) that runs northwest from Paglesham Churchend, under some poplars.

Good building stone is rare in Essex and East Anglia but one exception is the rock ferricrete. In Ice Age gravels the movement of iron-rich groundwater has resulted in the formation of hard, solid masses of ferricrete which is an iron pan at the level of the water table. It is basically an iron-cemented gravel but it can be extremely hard and durable. Ferricrete has been used in the construction of several Essex churches.

Paglesham ferricrete boulder (photo copyright Neil Harvey)