Hi Pam,

Frances Coakley's excellent web site 'Manx Notebook' has much info including some of relevance to the Foxdale Mines, especially transcriptions of Lamplugh's geological memoir - you might find what you are after there - try searching her site for Foxdale mine or whatever

http://www.isle-of-man.com/manxnotebook/search.htm

Apologies if you have already been there!
Ian