Crag Farm Pit is a classic Coralline Crag site and a site of special scientific interest (SSSI). It is rich in bryozoans and well-documented wave-features in the sands. There are few other fossils, but it is certainly a location to visit for anyone who is interested in bryozoans.
♦ Crag Farm Pit is near Sudbourne. The pit is on a farm and you will need permission from the farm owners to visit.
♦ The farm can be found to the southeast of Sudbourne. It is shown in 1:25,000 OS maps and, on 1:50,000 maps, it is marked as ‘Crag Farm’.
♦ From Sudbourne, there are three exits from the village. Take the eastern exit. When you come to a junction, turn right. At the second junction, turn left and you will find Crag Farm.
♦ Ref: 52.11602°N, 1.54558°E
FIND FREQUENCY: ♦♦♦ – This site is rich in bryozoans and you will certainly find some excellent specimens. However, other fossils are not so common. Shells can occasionally be found, but the actual shell beds are below the level of the pit and generally not exposed.
CHILDREN: ♦♦ – Quarries and pits, either working or disused, are no places for children as they present many dangers. Therefore, this location is not recommended for children.
ACCESS: ♦♦♦ – Crag Farm Pit is easy to find and the faces are kept clean as part of the SSSI notification. If you drive up to Crag Farm Pit and speak to the owners, they will probably allow access.
TYPE: – Fossils are found in the cliff face, which is constantly being eroded by wind and rain. The pit floor is grassed over, but kept cut to make access easy. Note that digging is not permitted at this site and you should only take one or two specimens.
Well-preserved colonies of the bryozoans (Eschara pertusa) are the most common find here. The site is well documented for this fossil, along with the spectacular round bryozoans, Meandropora tubipora. When complete, these specimens are the size of tennis balls. If you find a broken one, you can see the internal structure.
Shells and other fossils are rare at this site, as the beds are below floor level in the pit. However, shells can occasionally be found, such as scallops. To find fossils, search the cliff faces, as these are kept clean and constantly eroded by the wind and rain.
The sediments at Crag Farm Pit are Pliocene in age and part of the Coralline Crag Formation. This is made up of carbonate-rich skeletal sands. The acid-insoluble sand fraction is moderately- to poorly-sorted medium-grained sand. It has a low mud content and the basal lag gravel is rich in pebbles of phosphatic mudstone largely derived from the Thames Group.
Crag Farm Pit is notified as an SSSI due to its geological importance, Faces at the pit provide one of the best available exposures in the Coralline Crag and wave facies. About 5m of crag is exposed showing well-defined, large-scale cross-stratification. Conspicuous calcite veins are also present, which may be related to diagenetic removal of aragonitic material during a sub-aerial phase of solution.
Although there are no major safety issues at this site, you should follow the country code and use common sense at all locations. Some of the faces could collapse at any moment, so take care and do not collect from the overhanging areas.
A trowel or knife can be used for removing the shells from the shell beds. However, these are fragile, so paper and specimen boxes should also be taken.
This site is an SSSI. This means you can visit the site, but hammering the bedrock is not permitted. For full information about the reasons for the status of the site and restrictions please download the PDF from Natural England – SSSI Information – Crag Farm Pit