The mines of Laurion are ancient mines located in southern Attica between Thoricus and Cape Sounion, approximately 50 kilometers south of Athens, in Greece. The mines are best known for producing silver, but they were also a source of copper and lead. A number of remnants of these mines are still present in the region. The mines were exploited in prehistoric times as a source of copper and galena, a lead ore. In the classical period, mining in the area resumed. The Athenians used large numbers of slaves to mine the area, with the silver produced contributing significantly to the city's wealth. Abandoned in the 1st century BC, the mines were reactivated in 1864 and mined for their lead by French and Greek companies until 1978.
History
Ancient Times
Referring to the mines in his 354 BC work Ways and Means, Xenophon wrote:
It is clear, I presume, to every one that these mines have for a very long time been in active operation; at any rate no one will venture to fix the date at which they first began to be worked.
In fact, the exploitation of the mines stretches from the Bronze Age: isotopic analyses of lead present in objects of this era indicate that they were made in large part from metal extracted from the Laurion mines. The earliest evidence for mining activity at Laurion comes from the Late Neolithic period, around 3,200 BC. Mining became more systematic starting from the late sixth-century BC, and in the fifth century it was an important source of revenue for Athens. During this period, the city began to mine a new and particularly rich vein, which unlike the two which had previously been exploited did not appear on the surface. During the tyranny of Pisistratus systematic exploitation of the mineral resources of Athens began. Shafts were driven down into the ground and galleries opened where slaves, chained, naked, and branded, worked the seams illuminated only by guttering oil lamps. An unrecorded number were children. It was a miserable, dangerous, and brief life. This discovery meant that at the beginning of the second Persian invasion of Greece, the Athenian state had at its disposal 100 talents. Rather than distribute this wealth amongst the citizens of Athens, Themistocles proposed that this money should be used to construct 200 triremes, which were used to conduct the naval campaign against Persia which culminated in victory at the Battle of Salamis in 480 BC.
Modern Times
Mining at Laurion resumed in 1864. Renewed mining involved both the processing of ancient slag for remaining lead and silver and the extraction of fresh ore. Mining of zinc ore was a commercially significant in the Laurion area in modern times. It was mined from reactivation in 1864 until 1930. Iron ore was also mined through the 1950s. The mines continued to be active, producing silver and other metals until profitable sulfide deposits were exhausted in 1978.
Geology
The mines of Laurion are situated in the Attic-Cycladic metamorphic complex. Structurally, the Laurion area bedrock consists of a recumbent fold in the Kamariza marble with the Kamariza schist forming a hinge. Atop the folded marbles lie a layer of limestone deposited during a marine transgressive episode in the Jurassic and lower Cretaceous. This limestone layer is topped by Jurassic blueschists and overthrust, metamorphosed ophiolite. Miners in the 19th century organized the major deposits in this sequence into three separate contacts. The first contact is located within the transgressive limestones and consists of lead, zinc and silver sulfide minerals. The second contact occurs between the upper Kamariza marble and the Kamariza schist. This deposit consists of cerussite and smithsonite ores. The third contact occurs between the lower Kamariza marble and Kamariza schist. This deposit contains cerussite and iron oxides.
