Those objects told a story far older than the nineteenth century. Radiocarbon dating placed the tube at around 820 years before present, confirming that people were working copper at Derrycarhoon during the medieval period, centuries before the industrial-era miners arrived.

The site is considerably more layered than that single medieval date suggests. When mineral exploration began in 1846, it initiated several subsequent phases of disturbance and infilling across a spoil spread of roughly 780 square metres. Within that area, three distinct types of mining can be identified: a nineteenth-century shaft-and-gallery system descending to around 30 metres; six or seven shallow open-cast workings of unknown age; and a complex of six parallel trench mines, their lengths ranging from 7 to 55 metres, their depths from 3 to 13 metres, and their dates uncertain. None of the original workings survive intact above ground today. Further complicating the picture, stone mauls of the Mount Gabriel type were recovered from the site. Stone mauls are rounded hammer-stones used in Bronze Age copper mining, named after a well-documented prehistoric mine on the Mizen Peninsula not far away. Their presence at Derrycarhoon hints at prehistoric activity, though no secure archaeological context has been established for them at this site. Taken together, the evidence suggests a place where people returned to extract copper across potentially thousands of years, each phase partially obscuring the one before it.