The Alveston Bone Fissure is the remnant of a cave system. Stalagmite was formed on the basal silt. Later boulder falls opened the roof of the cave to the surface and it became a pitfall for animals during the eemian inter-glacial. The bone-bearing cone of dejection was truncated by erosion followed by deposition of thermoclastic scree, presumably of Weischelain age, and finally by post-glacial red loam. The site was mined for lead and quarried in the 1750s. Excavations were made in 1960-1963. A report on the soils forms part 2.