When the site was inspected, it had already been covered over with slag material originating from the Tynagh mines, effectively burying one kind of extraction beneath the residue of another.

Tynagh, a few kilometres to the south-east in County Galway, was the site of a major lead and zinc mine that operated from the 1960s until its closure in 1981. Slag, the glassy or stony waste left after ore has been processed, was produced in considerable quantities during such operations, and its spread into the surrounding landscape was not uncommon. The fact that it found its way onto this gravel pit suggests the material was used as infill or levelling matter, a practical disposal solution that quietly reshaped the local ground.