Geology Site Account

Site name: Ridgnalls Puddingstone

Grid reference: TL 9826 3218

Brief description of site:

A rare example of a puddingstone in this part of Essex. Probably local derived from gravel workings in the Kesgrave formation of the ancestral Thames river that once flowed across this area.

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Details

Puddingstone was formed around 55 million years ago when the climate of Britain was hot and a layer of pebbles beneath the surface of the ground became cemented with quartz. They are thus very resistant to erosion and have survived the rigours of the Ice Age. They originated on the Hertfordshire – Essex border, and were probably carried by the River Thames when it flowed north of its present course.

The formation of silcretes (which includes sarsens and puddingstones) has been the subject of recent scientific debate. Research has compared the conditions under which sarsens and puddingstones may have been formed with the present day climate in the Kalahari Desert and parts of Australia.