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dc.contributor.authorLamont, Thomas N.
dc.contributor.authorRoberts, Nick M.W.
dc.contributor.authorSearle, Michael P.
dc.contributor.authorGopon, Phillip
dc.contributor.authorWaters, David J.
dc.contributor.authorMiller, Ian
dc.identifier.citationLamont , T N , Roberts , N M W , Searle , M P , Gopon , P , Waters , D J & Miller , I 2020 , ' The age, origin and emplacement of the Tsiknias Ophiolite, Tinos, Greece ' , Tectonics , vol. 39 , no. 1 , e2019TC005677 .
dc.identifier.otherPURE: 261946916
dc.identifier.otherPURE UUID: 0479a97f-c1ee-40a9-820a-f02759ae6219
dc.identifier.otherRIS: urn:EF1B2D1645530018D6BDE196270DF9E8
dc.identifier.otherScopus: 85078399542
dc.identifier.otherWOS: 000529939200001
dc.descriptionThis work forms part of Thomas Lamont’s D.Phil project funded by the Natural Environment Research Council (Grant No. NE/L0021612/1). Analytical work at the NERC Isotope Geosciences Laboratory was funded by NIGFSC grant IP-1597-1115.en
dc.description.abstractThe Tsiknias Ophiolite, exposed at the highest structural levels of Tinos, Greece, represents a thrust sheet of Tethyan oceanic crust and upper mantle emplaced onto the Attic-Cycladic Massif. We present new field observations and a new geological map of Tinos, integrated with petrology, THERMOCALC phase diagram modelling, U-Pb geochronology and whole rock geochemistry, resulting in a tectono-thermal model that describes the formation and emplacement of the Tsiknias Ophiolite and newly identified underlying metamorphic sole. The ophiolite comprises a succession of partially dismembered and structurally repeated ultramafic and gabbroic rocks that represent the Moho Transition Zone. A plagiogranite dated by U-Pb zircon at 161.9 ± 2.8 Ma, reveals that the Tsiknias Ophiolite formed in a supra-subduction zone setting, comparable to the "East-Vardar Ophiolites", and was intruded by gabbros at 144.4 ± 5.6 Ma. Strongly sheared metamorphic sole rocks show a condensed and inverted metamorphic gradient, from partially anatectic amphibolites at P-T conditions of ca. 8.5 kbar 850-600 °C, down-structural section to greenschist-facies oceanic metasediments over ~250 m. Leucosomes generated by partial melting of the uppermost sole amphibolite, yielded a U?Pb zircon protolith age of ca. 190 Ma and a high-grade metamorphic-anatectic age of 74.0 ± 3.5 Ma associated with ophiolite emplacement. The Tsiknias Ophiolite was therefore obducted ~90 Myrs after it formed during initiation of a NE-dipping intra-oceanic subduction zone to the northeast of the Cyclades that coincides with Africa's plate motion changing from transcurrent to convergent. Continued subduction resulted in high-pressure metamorphism of the Cycladic continental margin ~25 Myrs later.
dc.rightsCopyright © 2019. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.en
dc.subjectTsiknias Ophioliteen
dc.subjectMetamorphic soleen
dc.subjectSubduction initiationen
dc.subjectTHERMOCALC Phase Diagram Modellingen
dc.subjectU–Pb geochronologyen
dc.subjectOphiolite obductionen
dc.subjectGE Environmental Sciencesen
dc.titleThe age, origin and emplacement of the Tsiknias Ophiolite, Tinos, Greeceen
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews. School of Earth & Environmental Sciencesen
dc.description.statusPeer revieweden

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