Weathering On Boulders, Burial Cairns

by JimPCame across the following online book titled The Burial Cairns and the Landscape in the Archipelago of Åboland, SW Finland, in the Bronze Age and the Iron Age. It has an excellent section, linked below, on the weathering of burial cairns and boulders, and also a discussion of what we would call, "depression piles."

http://herkules.oulu.fi/isbn9514268024/html/x1990.html