Like politics, all epochs are local.
These peat bogs were not themselves mines. Nor were they necessarily ever sites of metal use by humans. Still, in the peat is a record of metal use over the ages. The data are in the trace minerals present in the soil because they precipitated with rain out of polluted skies.
The metal use timeline that the researchers have constructed for Iberia coincides with much of what's known about the Stone Age, the Bronze Age, Celtic and Roman culture, and the industrial revolution both locally and globally. Uninhabited and even never-inhabited areas, it seems, can be an ongoing resource for investigations of early mining and metallurgy practices, and, hence, early culture.