Troodos Ophiolite, Cyprus
The Apliki Mine, NW Troodos: © Andrew Martin
The Troodos Mountains on the Mediterranean island of Cyprus are part of an ophiolite complex; an ophiolite is an uplifted fragment of oceanic crust and the Troodos ophiolite is a bigger version of the one we see at The Lizard in Cornwall. Troodos formed at the bottom of the Tethys Ocean during the Cretaceous around 92 Myrs ago. During the Neogene (20 Myrs ago) the island began to uplift due to fluid-rock reactions deep within mantle rocks; the uplift was uneven and centred around Mt.
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Pyrite 'Fools Gold': © Andrew Martin
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Olympos and has led to the exposure of a complete, concentric sequence of ophiolitic rocks. Subsequent exposure and erosion of the sediments which formed above Troodos means you can walk from the mantle (several km below our feet) to the modern seafloor. The uplift of Troodos is ongoing and Cyprus remains tectonically
active, this is due to the subduction of the African plate below the Eurasian (Anatolian) plate to the south of Cyprus at the Cyprian Arc.
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Blue staining often indicates copper secondary minerals such
as malachite: © Andrew Martin
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The Troodos ophiolite is exceptionally well preserved, it was not metamorphosed (deformed) during uplift, this means we can use Troodos as an analogue for processes which occur on the modern seafloor (e.g. The Mid Atlantic Ridge). Cyprus is particularly interesting as Troodos is an on land analogue for modern day seafloor hydrothermal mineralisation hosting over 90 ‘black smoker’ copper rich mineral deposits. These deposits form at spreading ridges deep on the seafloor through the interaction of super-heated seawater with igneous rocks deep within the oceanic crust. The hot metal rich fluid is then vented on the seafloor forming black smoker deposits rich in copper and pyrite commonly known as ‘fool’s gold’. Copper has been mined in Cyprus for thousands of years and is still mined today from the islands last active mine Skouriotissa. Copper is so important in Cypriot history that many believe the island was actually named after the Greek word for copper ‘Kúpros’.
In recognition of the scientific, cultural and geological significance of Troodos, in 2008 UNESCO designated Troodos as a Geopark; an area of special geological significance.
Further reading:
Geological Survey: www.moa.gov.cy/moa/gsd/gsd.nsf
Troodos Geopark: www.troodos-geo.org