Geology Site Account

Part of a submerged forest, about 6,000 years old, is exposed on the Thames foreshore at Rainham Marsh.

The forest, consisting of fallen tree trunks and roots, is of Neolithic age, a time when sea level was much lower. Following the end of glacial conditions some 10,000 years ago, alluvium (silts and clays with seams of sand and gravel) was laid down by the River Thames on its floodplain. Trees colonised the mud flats when there were minor temporary falls in sea level and died when sea level rose. The site has educational importance in the interpretation of sea level changes since the end of glacial conditions some 10,000 years ago, and how this relates to our current concerns about global warming.

A written record of this site was made in 1712 by Reverend William Dereham, Vicar of Upminster. There are other submerged forests along the Thames (e.g. at Purfleet nearby and on the other side of the river at Erith) some of which were studied as early as 1665.

The sea wall footpath (Havering Riverside Path) passes near the site. Rainham Railway Station is about 2 miles distant. The submerged forest can only be seen at low tide.

6,000 year old tree trunks on the foreshore at Rainham. Photo: W.H. George