At Copa Hill (Cwmystwyth) studies have been carried out on the wood and charcoal
recovered from the mine as well as on the pollen plant fossils and even beetle remains.
These have been preserved within the peat and organic silt infill that accumulated
both during and after mining had ceased. This can tell us much about the ancient
By coring the peat basins closest to these upland mines, and by dating the peat layers
and counting representative samples for pollen, it has been possible to reconstruct
some of the ancient vegetation histories. By this means we can detect any de-afforestation
which has taken place as a result of mining or smelting. In most cases, these Early
Bronze Age mining events seem to have had little impact on the surrounding woodland.
This website was made possible by a grant from the Cambrian Archaeology Association
Peat bog archives can also be used for detecting the presence of early mining or
smelting where archaeological evidence is lacking.
It would appear that the mining campaigns were small-scale and probably only seasonal
activities – sometimes carried out intermittently over several hundred years.
The larger mines such as those on the Great Orme (Llandudno) may have been worked
more continuously throughout the Bronze Age
Peat bogs can also provide us with a useful archive of past metal pollution.
Raised bogs that are rain-fed (ombrotrophic) collect atmospheric fall-out over time.
This includes the lead and copper which might be present within wind-blown dust emanating
from nearby mines or within smoke from smelting sites.
This dust collects and gradually accumulates in the surface vegetation of the bog.
These variations in pollution then become fixed and immobile within different levels
of the peat. We can record these ‘peaks’ by digesting a succession of peat samples
and then analysing these for the metals that they contain.
Early Bronze Age mining at Cwmystwyth is clearly revealed by the presence of elevated
copper within the base of the blanket bog on Copa Hill.
The record for copper and lead within the peat in a C14-dated pollen monolith. diagram
(Note, the high copper (120ppm) near the base. Site CH2)
Peat monolith site on Copa Hill (CH1). (Mighall et al, 2002)