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The age, origin and emplacement of the Tsiknias Ophiolite, Tinos, Greece
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dc.contributor.author | Lamont, Thomas N. | |
dc.contributor.author | Roberts, Nick M.W. | |
dc.contributor.author | Searle, Michael P. | |
dc.contributor.author | Gopon, Phillip | |
dc.contributor.author | Waters, David J. | |
dc.contributor.author | Miller, Ian | |
dc.date.accessioned | 2020-01-22T15:30:05Z | |
dc.date.available | 2020-01-22T15:30:05Z | |
dc.date.issued | 2020-01-20 | |
dc.identifier | 261946916 | |
dc.identifier | 0479a97f-c1ee-40a9-820a-f02759ae6219 | |
dc.identifier | 85078399542 | |
dc.identifier | 000529939200001 | |
dc.identifier.citation | Lamont , 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 . https://doi.org/10.1029/2019TC005677 | en |
dc.identifier.issn | 0278-7407 | |
dc.identifier.other | RIS: urn:EF1B2D1645530018D6BDE196270DF9E8 | |
dc.identifier.uri | https://hdl.handle.net/10023/19336 | |
dc.description | This 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.abstract | The 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.format.extent | 46615601 | |
dc.language.iso | eng | |
dc.relation.ispartof | Tectonics | en |
dc.subject | Tsiknias Ophiolite | en |
dc.subject | Metamorphic sole | en |
dc.subject | Subduction initiation | en |
dc.subject | THERMOCALC Phase Diagram Modelling | en |
dc.subject | U–Pb geochronology | en |
dc.subject | Ophiolite obduction | en |
dc.subject | GE Environmental Sciences | en |
dc.subject | DAS | en |
dc.subject.lcc | GE | en |
dc.title | The age, origin and emplacement of the Tsiknias Ophiolite, Tinos, Greece | en |
dc.type | Journal article | en |
dc.contributor.institution | University of St Andrews. School of Earth & Environmental Sciences | en |
dc.identifier.doi | https://doi.org/10.1029/2019TC005677 | |
dc.description.status | Peer reviewed | en |
dc.date.embargoedUntil | 2020-01-20 |
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