Geology Site Account

Site name: Arkesden War Memorial, St Marys Churchyard, Arkesden.

Grid reference: TL 4821 3456

Brief description of site: The war memorial in Arkesden churchyard consists of a single block of Hertfordshire puddingstone. The memorial sits just inside the churchyard and is accessible at all times. It is clearly visible from the roadside.

Summary of the geological interest

The war memorial in St. Marys churchyard consists of a very large single boulder of Hertfordshire puddingstone 1.7 meters by 1.7 metres by 0.8 metres in size with a pebble-free (sarsen) layer within it. It is one of the most unusual war memorials in Essex.

Hertfordshire puddingstone is a unique type of rock containing well-rounded flint pebbles bound together with quartz cement. It is named after its resemblance to a plum pudding and the fact that it can be found in Hertfordshire in-situ. The cement and pebbles are homogeneous and both equally hard, which makes puddingstone a very tough rock and very resistant to erosion. This particular puddingstone boulder is one of the most conspicuous examples in Essex.

Arkesden is unique in Essex for the number of puddingstone and sarsen stone boulders that are scattered around the village. They can also be seen on the roadside, in the stream bed, by the inn, and in private gardens. These boulders are known as glacial erratics and were probably carried here first by an early course of the River Thames, and then scattered by the Anglian Ice Sheet which covered almost the whole of Britain during the coldest period of the Ice Age, some 450,000 years ago.

Scientific interest and site importance

Hertfordshire Puddingstone was formed around 55 million years ago when the climate of Britain was hot and a layer of sand beneath the surface of the ground became cemented with quartz. 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.

The boulders of puddingstone that are found in Essex most probably originated in Hertfordshire and were brought to Essex by the Thames when it flowed far to the north of its present course. However, the abundance of puddingstones and sarsens in Arkesden raises the intriguing possibility that there might have once been a more local source.

Erratic boulders link geology and social history. This boulder was apparently brought here from somewhere on the Wood Hall estate, probably less than a mile to the south, and transported by horse-drawn sledge (Green 2014). Investigations are currently being made to establish its precise origin.

The Arkesden War Memorial Puddingstone. Photo: M. Ralph