[SunkenCiv]

The need for rare tin during the bronze age made discoveries even of the Americas possibble by bronze age mariners - but when the iron age came about the dicoveries were lost as the need for tin was reduced.

Hey, I think you're onto something, although I think it was the other way around -- as deposits were mined out, or access otherwise lost (for example, due to the climate cycle, or the fall of Carthage, or rising prices/barter rates) to the mines, or, as the energy costs fell (due to changes in the type or supply of fuel), iron superceded bronze (over a long period).

Also, the introduction of coined currency altered the nature of markets.

[Destro]

Carthage fell during the iron age so her fall would not have been a factor. The theory is not mine by the way but a Scandanavian archeologist - the guy found that famous viking long boat and restored it-his name escapes me.