Forms of relative dating
The eventual disappearance of copper-arsenic alloys is difficult to explain.
Metallurgy customarily refers to commercial as opposed to laboratory methods.
It may be that tin bronzes were eventually preferred owing to the chance of contracting arsenic poisoning from fumes produced by the oxidation of arsenic-containing minerals.
As the weathered copper ores in given localities were worked out, the harder sulfide ores beneath were mined and smelted.
In addition, higher furnace temperatures would have created more strongly reducing conditions (that is to say, a higher carbon monoxide content in the furnace gases).
An early piece of iron from a trackway in the province of Drenthe, Netherlands, has been dated to 1350 .