Limestone Pavement
Whilst reinstating a stretch of little-used public footpath in Badgers Wood in July 2018, volunteers uncovered an unusual limestone rock formation. Further digging and research showed this to be a “limestone pavement” with its characteristic crevices and gulleys. A section 5m x 5m was exposed which looks quite dramatic.
Our focus then moved to another stretch, near the top junction of the Fern Way and the Geology Trail, which showed signs of a similar rock formation.
After a lot of hard work, a large area of limestone pavement has been exposed which is a remarkable feature to visit.
The local RIGS geologist group is really excited by the discovery of this rare limestone pavement and we hope this will lead to further investigation and possibly SSSI status.
What is a limestone pavement?
A limestone pavement is a flat expanse of exposed limestone formed by a combination of chemical weathering and erosion. Most limestone pavements in the UK are formed on Carboniferous limestone and whilst there are superb examples in Yorkshire, they are an extremely rare geological feature in the south of England.
How do limestone pavements form?
- During the ice ages, much of Britain was covered by ice sheets and glaciers. During this time, the soil and weaker surface rocks were often scoured away, leaving broad expanses of exposed limestone.
- With the retreat of the glaciers, moraine material was left behind and a forest eventually established itself. Mildly acidic rain water percolated through the soil which gradually dissolved the limestone surface.
- Under the soil, the rain water picked out the joints in the limestone and gradually widened them by dissolving the rock. This created deep fissures called grykes. The blocks of limestone (or clints) were also attacked by the rain and small holes and gulleys (or karren) formed on their surface.
- When the ice finally retreated, the soil on the top of the limestone pavement was eroded, washed down into the grykes and removed altogether by the drainage system. The exposed limestone pavement would have been constantly chemically weathered, resulting in the further widening of the grykes and the karren.
- Badgers Wood’s extensive limestone pavement is today buried under 5 – 20cms of soil. Sometime in the last thousand years, decomposing vegetation has accumulated on its surface, slowly turning into soil and has consequently buried the once exposed rock surface.