GEODIVERSITY
Sand & Gravel Case Study

Asham

Key Highlights

• The creation of an alternative geological conservation section adjacent to the original landfilled quarry site.
• Improved safety and access to the geological interest at a site.

Geological and Historical Background

Asham quarry was initially worked for chalk and subsequently granted permission for landfill. The quarry is designated a SSSI for the presence of post glacial and Holocene deposits that provide a detailed record of environmental and climatic change. These deposits overlie the chalk.

Opportunities for Geological Conservation

Negotiations between the mineral operator, local planning authority and English Nature ensured the formation of an alternative exposure, leaving the quarry void available for landfill. Geological Conservation Techniques The Quaternary deposits of interest are located at the top 4m to 5m of the quarry. Landfilling the base of the site up to the level of the Quaternary deposits would have made access to the deposits easier in one respect. However, there were concerns regarding the safety of the site due to the unstable nature of the unconsolidated sediments and the loss of void space. There were also concerns over the visual impact of this method of restoration within the South Downs Area of Outstanding Natural Beauty (AONB).

In order to finalise the landfill arrangements and permission for the quarry void, the developer, the local authority and English Nature considered alternative ways of maintaining and managing the interest on the site.

The developer funded the formation of an alternative exposure in the Quaternary deposits adjacent to the site as mitigation for infilling the original quarry.

The section took two days to construct and comprises an amphitheatre shaped void, which at its maximum is around 3m deep. Fencing surrounds the exposed section, with a gate and steps for entry. Access is obtained from the site office and is through a locked gate at the perimeter of the site.

Ongoing Management Needs

The exposure is still relatively new. However future management will be required to ensure that vegetation does not encroach on the exposed faces and some excavation may be required if the soft sediments degrade.

Infrastructure in the form of fences and gates also needs to be maintained to ensure that there is no damage to the site from grazing.

Further work is required to re-examine palaeoecological information from the new site to tie in with the exposures in the former quarry which were well researched around 40 years ago.