Editing Thasos (section)

==Geography==
[[File:Thasos.jpg|thumb|Thasos from space, April 1993]]
[[File:Thasos2022OSM.png|thumb|left|Detailed map of Thasos]]
Thasos is located in the northern Aegean sea approximately {{convert|7|km|0|abbr=on}} from the northern mainland and {{convert|20|km|0|abbr=off}} south-east of [[Kavala]]. It is of generally round shape, without deep bays or significant peninsulas. The terrain is mountainous but not particularly rugged, rising gradually from coast to centre. The highest peak is [[Ypsario]] (Ipsario), at {{convert|1205|m|0|abbr=off}}, somewhat east of centre. Pine forest covers much of the island's eastern slopes.

Historically, the island's population was chiefly engaged in agriculture and stockbreeding, and established villages inland, some of them connected via stairways (known as skalas) to harbors at the shore. The local population gradually migrated towards these shoreline settlements as tourism began to develop as an important source of income. Thus, there are several "paired villages" such as Maries–Skala Maries, with the former inland and the latter on the coast.

===Geology===
{{technical|section|date=January 2013}}
[[File:Epitropou 4.jpg|thumb|left|200px|Geological and Metallogenic map of Thasos island.]]

The island is formed mainly by [[gneiss]]es, [[schist]]s and [[marble]]s of the [[Rhodope Mountains|Rhodope]] massif. Marble sequences corresponding to the [[Falakro]] marbles intercalated by schists and gneisses, are up to 500&nbsp;m thick and are separated from the underlying gneisses by a transition zone about 300&nbsp;m thick.

The rocks have undergone several periods of regional metamorphism, to at least upper [[amphibolite]] facies, and there was a subsequent phase of retrograde metamorphism. At least three periods of regional deformation have been identified, the most important being large scale [[isocline (geology)|isoclinal folding]] with axes aligned north-west. The T-zone is deformed and is interpreted by some authors as a regional thrust of  pre-major folding age. There are two major high angle fault systems aligned north-west and north-east respectively. A large low-angle thrust cuts the gneiss, schist and marble sequence at the south-west corner of the island, probably indicating an overthrusting of the Serbomacedonian Massif onto the Rodope Massif.

The [[Late Miocene]] oil-producing Nestos-Prinos basin is located between Thassos island and the mainland. The floor of the basin is around 1,500 m deep off the Thassos coast (South Kavala ridge; Proedrou, 1988) and up to 4.000–5.000 m in the axial sector between Thassos and the mainland. The basin is filled with Late Miocene-Pliocene sediments, including ubiquitously repeated evaporite layers of rock salt and anhydrite-dolomite that alternate with sandstones, conglomerates, black shales, and [[uranium|uraniferous]] [[coal measures]] (Proedrou, 1979, 1988; Taupitz, 1985). Stratigraphically equivalent rocks on the mainland are clastic sediments with coal beds, marine to brackish fluvial units and travertines.

===Mining history===
The earliest mining on the island has been dated to around 13,000 BC, when [[Paleolithic]] miners dug a shaft at the site of the modern-era Tzines iron mine for the extraction of [[limonite|limonitic]] ochre.<ref>Kovkouli ''et al''. 1988.</ref> Mining for base and precious metals started around the 7th century BC with the Phoenicians, followed in the 4th century by the Greeks, then the Romans. These later mines were both open-cast and underground, mostly to exploit the island's numerous [[karst]] hosted calamine deposits for their lead and silver. Gold, copper and iron were also found; the [[Byzantine]]s quarried marble on the island.

In the early 20th century, mining companies (most notably the Speidel mining company) exploited the island's [[zinc]]-[[lead]] rich [[calamine]] ores, with a yield of around 2 million tonnes, and a processing plant at [[Limenaria]] produced [[zinc oxide]]. Iron ore was mined on a significant scale from 1954 to 1964, with a yield of around 3 million tonnes. Since 1964, surveys have established the existence of a deep-level zinc-lead deposit, but the only mining activity on the island has been marble quarrying.

<gallery class="center">
File:Sellada.jpg|[[Lead]]-[[zinc]] mine at Sellada
File:Cupanada.jpg|Iron mine of Koupanada
File:GR Thasos 81 Grube E1 01.jpg|Gold mine
File:Tzines.jpg|Iron mine at Tzines, with Paleolithic mine-tunnel
File:Marble quarry Thasos island.jpg|Marble quarry of Alyki
</gallery>