The fossil ridge-transform intersection preserved in the Troodos ophiolite, Cyprus, exposes two dissimilar segments of a paleo spreading center. North of the Arakapas fossil transform fault an intact oceanic lithosphere is preserved. However, south of the Arakapas transform, in the Limassol Forest, units of the ophiolite are juxtaposed in a complex way. In the Limassol forest extensive talc-amphibole-chlorite metasomatic zones and rodingitized gabbro boudins occur within a strongly foliated serpentinite shear-zone separating ultramaFics from sheeted dykes. Localized serpentinization, metasomatism and deformation along shear-zones are major characteristics of oceanic detachment faults. δ18O values of the serpentine in the Limassol Forest are invariably lower than mantle values (0 to 5.7‰; n=26), consistent with serpentinization during seaFloor spreading. δ18Oserp decreases from 4 to 0‰ towards the contact, suggesting that this shear zone was acting as a conduit for seawater circulating at moderate to high temperatures (~150 - 250°C) close to the spreading axis. Accordingly, the mantle sequence of the Limassol Forest is suggested to be exhumed at the footwall of an oceanic core complex, which explains the complicated structure of oceanic lithosphere exposed in the Limassol Forest. North of the Arakapas transform, the Mt. Olympus serpentinites comprise two generations of serpentinization. Early oceanic lizardite (δ18Oserp= +4 to +6‰) is heavily overprinted by late chrysotile veins of unknown source (δ18Oserp= +10 to +14‰; δ11Bserp= -6 to +13‰). The new data suggest that chrysotile is related to the emplacement of the ophiolite on the African margins. δ11Bserp values gradually decrease away from the Cyprus Arc subduction trench, resembling similar across arc trends recorded in magmas This suggests that Fluids released from the subducting slab beneath Cyprus in the last 2 m.y. migrated upward and overprinted the partially serpentinized mantle with thick chrysotile veins.
|State||Published - 13 Oct 2014|
|Event||International Symposium on Eastern Mediterranean Geology - Mugla, Turkey|
Duration: 13 Oct 2014 → 17 Oct 2014
|Conference||International Symposium on Eastern Mediterranean Geology|
|Period||13/10/14 → 17/10/14|