Animals dragged human bones in or out of caves, so mines would probably have had a similar history over time.
Grimes Graves "female goddess" figurine seems to be a hoax, according to Hutton anyway.
Apparently it was all very suspicious, excavation notes were never published, site notebook stopped on the day it was found, it looked freshly carved and there was an expert carver on site... Hutton doesn't believe there was an overarching mother goddess cult anyway, he reckoned that the venus figurines could just as well have exemplified obesity (not a good sign now - blame it on Mcdonalds) as showing signs of plenty, a bit like the plump buddha...