Geology Site Account

Site name: Shipwrights Wood

Grid reference: TQ 795 871

Brief description of site:

Impressive landslips on the steep slopes in this historic wood. The landslips provide information about the underlying geology. The geomorphological interest, combined with the botanical value of the site make this wood of great educational importance. Several aspects of geology and geomorphology can be learnt in a small area.

-----------------------------------------------------------------

Summary of the geological interest:

Shipwrights Wood occupies an area of steeply sloping ground where there have been numerous landslips over the last few thousand years. There are also ridges and ravines formed by stream erosion. The result is one of the most remarkable woods for natural landforms in Essex.

The geology is straightforward and consists of London Clay overlain by Claygate Beds which in turn is overlain by Bagshot Sand. These rocks were laid down in a warm, subtropical sea that covered much of south-east England during the Eocene period some 50 million years ago. The Bagshot Sand is a very fine-grained yellow sand and is often visible here in heaps thrown out from animal burrows.

An additional aspect of interest in the wood is the movement of ground water. This is demonstrated to good effect by a line of springs formed by water percolating through the sand and seeping out on meeting the impervious clay beneath.

-----------------------------------------------------------------

Scientific interest and site importance

The geological succession of London Clay, Claygate Beds and Bagshot Sand is similar to that in other places in south Essex such as the Langdon Hills. However, this site shows the succession in a compact area. The succession tells a story spanning several million years. As the sea became shallower, the clay became mixed with sand and London Clay was replaced with the sandy clay of the Claygate Beds. Sea level continued to fall and, as the coastline approached, Bagshot Sand was laid down across the county. The strata is horizontal but because of the sloping ground the London Clay occurs at the surface at the western end and the Bagshot Sand caps the high ground at the eastern end.

The landslips are a feature of the western scarp of the Claygate Beds in this area where the sandy strata, lying on slippery clay, has been lubricated by springs and made unstable. The line of springs marks the junction between the Claygate Beds and the London Clay and demonstrates ground water movement to excellent effect.

The landslips can be contrasted with the large-scale slips at Hadleigh Castle nearby. The importance of this site is referred to in Rackham (1986).

-----------------------------------------------------------------

Other information

Shipwrights Wood is a fine, varied woodland owned and managed by Castle Point Borough Council. It is an ancient wood of great botanical interest and records indicate that it dates back to at least 1300. The wood is described in detail by Rackham (1986).

Access is from Shipwrights Drive off Benfleet Road or by following the footpath from Hadleigh Castle Country Park. The wood is accessible at all times with car parking nearby.