Complex sentence: As silver was extensively used as a decoration material and a means for exchange, lead deposits were first worked in Asia Minor in 3000 BCE and subsequently in 2000 BCE in the Iberian peninsula by the Phoenicians; and in Athens, Carthage, and Sicily.
Split into simpler sentences: As silver was extensively used as a decoration material and a means for exchange, lead deposits were first worked in Asia Minor in 3000 BCE. Lead deposits were worked in 2000 BCE in the Iberian peninsula by the Phoenicians; and also in Athens, Carthage, and Sicily.