%0 Thesis %T Mesozoic Tectonics of the Aegean %T Tectonique Mesozoïc de l'Egee %T Insights from analogue modelling, petrology, geo- and thermo-chronology %+ Géosciences Rennes (GR) %A Kydonakis, Konstantinos %I Universite Rennes 1 %Y Jean-Pierre Brun (Jean-pierre.brun@univ-rennes1.fr %Y Frédéric Gueydan %Z Jean-Pierre Burg (Rapporteur) %Z Torgeir Andersen (Rapporteur) %Z Dimitrios Kostopoulos (Examinateur) %Z Claudio Faccenna (Examinateur) %8 2014-10-22 %D 2014 %K Tectonics %K Aegean %K Metamorphism %K tectonique %K Egée %K Métamorphisme %Z Sciences of the Universe [physics]/Earth SciencesTheses %X The Aegean Sea started to form since middle Eocene back-arc extension aecting thepreviously formed Hellenic Thrust Wedge. The latter was made by Mesozoic - Cenozoicaccretion of i) three continental fragments, namely Rhodopia, Pelagonia and ExternalHellenides, arranged in a SW-verging stack from NNE to SSW in the order listed, andii) the closure of two intervening oceanic domains now forming, from north to south, theVardar-Axios and the Pindos Suture Zones, respectively. The thickened crustal-scalewedge started to collapse, in a process driven by the Hellenic slab rollback, triggering thedevelopment of core complexes in the severely stretched Aegean crust. During the earlystage of extension, deformation localised to the hinterland of the crustal-scale wedge in thearea described as the Rhodope Metamorphic Province (or simply Rhodope).The Rhodope is an area of large-scale nappe tectonics and is considered unique for thegeology of the Aegean as it recorded both the Mesozoic convergence-related deformation andthe subsequent Cenozoic extension of the Aegean during which, part of the earlier fabrics werere-worked. During Cenozoic extension, the southwestermost part of the Rhodope, namelyChalkidiki block, escaped much of the related deformation as it remained in the hangingwallof the Kerdylion Detachment, a large structure related to the Aegean extension. Asa result, we selected the Chalkidiki block to study the Mesozoic tectonics of the Aegean.This study is based around a multidisciplinary approach that aims to unravel dierentaspects of the tectonics of North Aegean. For that purpose we have selected to study theChalkidiki block using a variety of geological methods. 1) We carried out several eld mappingcampaigns measuring the geometry of structural fabrics. An overview of the regionalgeometry is given in the compiled regional maps that illustrate the attitude of the measuredplanar and linear structural fabrics. 2) We evaluated the intensity of the metamorphic conditionsusing isochemical phase diagram sections calculated by minimisation of the Gibbsfree energy. Based on our model results, we inferred the existence of an early eclogite-faciesevent before the regional amphibolite-facies overprint. 3) We performed high- (U/Pb inzircon and monazite) and medium-temperature (40Ar/39Ar on micas) geochronology coupledwith low-temperature thermochronology and inverse thermal history modelling using aBayesian transdimensional inversion scheme. The modelling results delineated the completethermal path (T-t) of the study area from Cretaceous heating to Eocene near surface exposure.4) We modelled the Tertiary geological evolution of the North Aegean with reference tothe exhumation of the lower crust during core complex formation. Using scaled laboratoryexperiments we tested whether the gravity spreading of a crustal-scale thrust wedge that undergoesextension is a suitable process for the development of the Rhodopean core complexesduring the early opening of the Aegean. Our analysis suggests that strain localisation andcore complex development near the backstop of the area aected by extension is intrinsic tothe pre-collapse geometry of the orogenic wedge. %X Les Hellenides, qui font partie integrale de la chaine Alpes-Himalaya, aeurent a l'estde la Mediterranee. Elles resultent de la convergence vers le nord et de l'accretion, a la margeSud-Europeenne, de blocs continentaux appartenant au Gondwana. Dans cette region, lesdonnees de tomographie sismique mettent en evidence un seul panneau de lithosphere en subduction,ancre dans le manteau inferieur a 1600 km de profondeur. Les Hellenides resultentde l'empilement vers le Sud-Ouest, du Mesozoique au Cenozoique, de trois microplaques(Rhodopia, Pelagonia et les Hellenides Externes), avec fermeture de deux domainesoceaniques, formant maintenant du Nord au Sud, les zones de sutures du Vardar-Axios etdu Pinde.Une phase d'extension arriere-arc contr^olee par le retrait vers le sud du panneau plongeantHellenique a commence a l'Eocene moyen, aectant la cro^ute precedemment epaissie. Lesysteme Egeen represente la partie la plus etiree du domaine arriere arc et resulte du retraitde la fosse oceanique, d'environ 600 a 700km vers le sud. Les Hellenides internes ont subit uneextension de type "core complex" localisee dans la province metamorphique du Rhodope(ou Rhodope). Puis l'extension a migre vers la partie centrale de l'Egee, dans la region desCyclades. Depuis le Miocene moyen, l'extension est passee a une extension de type riftlarge, donnant naissance a de nombreux bassins sedimentaires marins et continentaux.Le Rhodope est un domaine precieux du systeme Egeen car la tectonique chevauchanteMesozoïque de grande echelle y est bien conservee malgre les eets ulterieurs de l'extensionEgeenne. C'est donc une localite privilegiee pour l'etude de la convergence Jurassique-Cretace des Hellenides. C'est aussi une region ideale pour etudier l'eondrement gravitairede la cro^ute hellenique epaissie au debut de l'extension egeenne. Cette superposition desdeformations liees a la convergence (epaississement) et de celles liees a l'extension (amincissement)dans un seul systeme geologique donne au Rhodope une signature particulieredans l'evolution du systeme Egeen, tres favorable pour l'etude des mecanismes de formationet d'eondrement d'une cro^ute orogenique epaissie. %G English %2 https://insu.hal.science/tel-01137808/document %2 https://insu.hal.science/tel-01137808/file/Kydonakis_Thesis.pdf %L tel-01137808 %U https://insu.hal.science/tel-01137808 %~ INSU %~ UNIV-RENNES1 %~ UR2-HB %~ CNRS %~ UR2-HB-T %~ GR %~ OSUR %~ UR1-THESES %~ UR1-HAL %~ UR1-SDLM %~ UR1-SDLMJONCH %~ GR-3T %~ UNIV-RENNES2 %~ GR-THESES %~ TEST-UNIV-RENNES %~ TEST-UR-CSS %~ UNIV-RENNES %~ INRAE %~ UR1-ENV