I found this on wikipedia which is interesting: >The appearance of a man-made pit has been attributed partly to the texture of sinkholes: "this filling would b

I found this on wikipedia which is interesting: >The appearance of a man-made pit has been attributed partly to the texture of sinkholes: "this filling would be softer than the surrounding ground, and give the impression that it had been dug up before",[38] and the appearance of "platforms" of rotten logs has been attributed to trees or "blowdowns" falling or washing into the depression.[39] An undetermined pit similar to the description of the early Money Pit had been discovered in the area. In 1949, workmen digging a well on the shore of Mahone Bay, at a point where the earth was soft, found a pit of the following description: "At about two feet down a layer of fieldstone was struck. Then logs of spruce and oak were unearthed at irregular intervals, and some of the wood was charred. The immediate suspicion was that another Money Pit had been found."[40]