Please would anyone who knew/knows a caver called John Jarvis (RJ Jarvis) from the Nottingham/Derby area contact me by PM. I understand he may have worked for the BGS.
I don't know of a John Jarvis at BGS, certainly not in the last 10-15 years but Deej Lowe may know him. There was an R.J Jarvis who wrote a paper in 1984 on the salt domes of Iran based at the Department of Mathematics, The University, Dundee DD1 4HN, Scotland, U.K if that helps.
I suggest you contact Deej.