Geology Site Account

Site name: Botany Pit

Grid reference: TQ 556 782

Brief description of site:

Beacon Hill in Purfleet has been extensively quarried for chalk and Botany Pit (a disused chalk quarry) is now an industrial estate. Important flint implement-bearing gravels are present on top of the Chalk, estimated to be 300,000 years old.

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Site description

At Beacon Hill the chalk strata rise to a height of almost 40 metres (120 feet) with good views along the estuary. This is the highest point of the Purfleet anticline which has brought the Chalk to the surface in Thurrock but most of the hill has now been quarried away. Just to the west of Beacon Hill is Botany Pit which originally showed Chalk capped with Thanet Sand and sandy pipes penetrating into the Chalk.

In the early 1960s the company operating Botany Pit extended the quarry by removing the overburden of sands and gravels that were banked up against the north side of the hill and lying directly on the Chalk. The deposits were found to be very rich in Palaeolithic stone tools and an archaeological excavation yielded hundreds of flint flakes and cores with some hand-axes. It has been referred to as a Proto-Levallois flint industry. Most of the material is in the British Museum but two hand-axes are in Thurrock Museum. Some bones of fossil mammals were also found including horse, red deer and probably bison.

Research on other sites in the vicinity has thrown new light on the origin of these deposits which also occur at Greenlands Pit to the east (Purfleet Chalk Pits SSSI). They are part of a sequence of sediments which are now known to have been deposited by the Thames when it flowed in a westerly direction along the northern edge of this chalk ridge. This stretch of the river was part of an S-shaped loop which was abandoned in later times.

The implement“bearing sediments at Botany Pit are thought to be about 300,000 years old and probably date from the early part of a glacial stage that is equivalent to Marine Isotope Stage 8.

Unfortunately, the section in Botany Pit was obscured when it was cut back to a low angle in the 1980s when the quarry was developed as an industrial estate.