Recently discovered in Wookey Hole, are deposits of a curious form of calcite. The story, here - http://darknessbelow.co.uk/?p=1002 contains links to research papers, and cavers who have seen similar deposits are asked to get in touch. Those odd piles of white stuff you have walked past countless times may be of great interest.

Tectonic or Cryogenic. ?

Here is a research paper on Cryogenic fracturing by a pair of researchers who have made studies in Devon and in more recent years on Mendip including Shatter Cave and Reservoir Hole.

http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=1093&context=ijs

The assumption is that as the fractured formations in both Shatter Cave and Reservoir Hole are within a few metres of a major fault they are tectonic and contemporaneous . We may be getting closer to a definitive answer as more papers are published. It seems likely that a study of Reservoir Hole will appear later this year. One of the authors has carried out dating analysis on Reservoir stal fragments. The latest fragment came from the choke sealing the route up to Trapdoor Chamber which gave a surprising result of only 10,000 years. One can clearly understand cryogenic fracturing caused by heave when underlying sediments are frozen but I would like to see more data on the discrete or catastrophic fracturing we see in Shatter and Reservoir. Possibly both agents of fracturing were at work.

Discrete fracturing and re-calcification of stal . Shatter Cave.



Catastrophic destruction of stal floor with underlying sediments. Cause unknown.



Classic case of fracture and re cementing Shatter Cave. ( Photo from original exploration )

Another view of the Leaning Tower of Pisa showing its position in the original phreatic tube. Subsequent vadose incision beneath.




Cryogenic calcite research is an interesting area and I am sure we will soon hear more about it in relation to Mendip and Devon caves.

By the way Nick's naming the big chamber in Reservoir Hole The Frozen Deep n  seems to be a case of nominative determinism as there appear to be cryogenic crystals in there!