2 minute read
Site management at Orford Castle Pit CGS
Caroline Markham, GeoSuffolk
The Suffolk Coast and Heaths Area of Outstanding Natural Beauty has a varied and often unique geodiversity, and GeoSuffolk has designated 18 County Geodiversity Sites (CGS), all with public access, within the AONB (there are also 25 geological SSSIs). Many of the exposures are in active marine cliffs, but 6 of the CGS are disused crag pits and these require some management as faces degrade and talus builds up over the years. This winter GeoSuffolk, with SCH AONB volunteers, refreshed the Coralline Crag pit at Orford Castle. Permission was needed from English Heritage because Orford Castle and its associated earthworks is a Scheduled National Monument and this took some doing as the documents had to go all the way up to the Secretary of State, but with EH’s help we achieved it with 36 hours to spare!
The work was undertaken on November 6th, a beautiful sunny day, and 16 volunteers assembled at the Castle at 9.30am with spades and rakes to tackle the vegetated talus build-up in the Coralline Crag pit south of the Castle. Work was undertaken along a section of the quarry face, exhuming several small and overgrown exposures. By the end of the day, a 3m Coralline Crag face, displaying some large scale current bedding structures in the creamy-yellow limestone, had reappeared from its accumulated debris and vegetation. Thank you SCH AONB volunteers!
Coralline Crag is unique to Suffolk - it is a 4 million year old limestone and the upper bed, locally known as the ‘rock bed’ has been used as a building stone in the past. Coralline Crag is used in the fabric of Orford Castle and it is likely that is was sourced in the pit, also the well in the Castle basement would have been dug through this rock to access the water table held up on top of the London Clay at depth. Thus the refreshed sections of the pit will help interpret the building and its site as well as providing a most attractive addition to the area by the earthworks.
This site management day was so successful that, at its Committee meeting in March 2015, GeoSuffolk made the decision to upgrade the official condition status of this CGS from GOOD STEADY to GOOD IMPROVING. English Heritage has been notified and also Suffolk County Council for its Defra Single Data List 160 record.
Orford Castle Pit 1 Photo: Caroline Markham
