Old maps show 3 shafts to the west of the track near Clapper Farm but there is no obvious trace other than various areas of gruffy ground. A local shepherd had no knowledge of the shafts, which were visited by E C Gray in 1921, but knew that copper mining had taken place in the area. To the north-east, on the other side of the track, there is a collapsed adit where a few pieces of barytes were found.
Murchison refers to workings at Norbury in Palaeozoic slaty rocks and Dines also refers to such rocks but Norbury Hill is clearly composed of red Longmyndian sandstones. Greig et al have suggested that these descriptions may refer to workings in Shuttocks Wood. It is most unlikely that Murchison would describe these distinctive sandy rocks as Palaeozoic slates. The mystery remains unsolved.