Care needed in G.B. Cavern, Charterhouse on Mendip

G.B. Cavern: formations in the roof of the Main Chamber. Photo: Linda Wilson

A rockfall has been reported in GB near the waterfall climb in Main Chamber.

There has been a recent fall of mud, gravel and smallish boulders on the left (when viewed facing downstream) of the waterfall climb, near the bottom of Main Chamber. The wall above the last part of the climb (the big steps) appears as it did before, but should be considered loose due to the recent fall. The top part is calcited but might be subject to further falls, although it is equally possible that it might not change for a long time. However, as assessing such future possibilities is not an exact science, care should be taken here, and everyone should conduct their own risk assessments whenever they approach this area from any direction. There are still loose rocks almost covering the steps and when inspected it was not possible to pass the steps without using the unconsolidated debris. The floor below the climb is currently covered with unconsolidated debris and the boulders here will move underfoot when stepped on, so care should also be taken here.

This waterfall has been formed on a major vertical structural fault (see Ford, D.C., 1964. On the Geomorphic History of G.B. Cave, Charterhouse-on-Mendip, Somerset. UBSS Proceedings, 10(2) pp 149-188) which states that there is much fault breccia to be found and so events of this nature are likely to occur from time to time.

Both the trip on which this fall was discovered and the one on which its current condition was investigated were carried out in accordance with the prevailing government Covid-19 guidelines. For more information see the Council of Southern Caving Clubs website.

Information received from Charterhouse Caving Company Ltd.