yes they were 6 miles underground then. The rock is limestone
They used torches the same at the 18c lads who went down for a 'dare' and wrote their name in the the soot from the torches.
When the paintings at Rouffignac were done they would have had to lie on their backs to paint as they chose a part where the ceiling was low. It has now been dug out for easier access for visitors.
I looked up the Chauvet site that BB put on,
hoping it was in the Dorgogne (I'll be there next week
) but it is in the Ardeche so won't be ableto see it.