re: Thorium, eh?
Excellent run-through.
The Wet Mountains of Colorado were explored for Th in the late 1950's, funded by the Atomic Energy Commission of the time.
I was worried more about Thorite, the Th/U zircon, which is radioactive, and a possible mineral candidate in this setting. See my repy to Gary about these particular deposits for a good link.
As I recall, this vein ran almost a 1000 ppm Th.