ANCIENT MINING Earth Sci
Piles of weathered waste rock from suspected Roman mine. There is as much as 20,000 ppm lead, 7000 ppm zinc, and 5000 ppm arsenic in the dump soils, much higher than soils over similar rock outside the mining area where maxima rarely exceed 40 ppm lead, 115 ppm zinc, and 100 ppm arsenic.
