U-Pb zircon geochronology of intrusive rocks from an exotic block in the Late Cretaceous – Paleocene Taraklı Flysch (northern Turkey): Constraints on the tectonics of the Intrapontide suture zone

In the Boyal\u131 area (northern Anatolia), a thick succession of the Early Maastrichtian - Middle Paleocene Tarakl\u131 Flysch crops out. The Tarakl\u131 Flysch represents a foredeep sediment deposited during the final stage of collision between the Sakarya and Istanbul-Zonguldak continental margins, that developed as a consequence of the closure of the Intrapontide oceanic basin. The top of the Tarakl\u131 Flysch is characterized by a level of slide-block in shaly-matrix lithofacies that can be considered as the result of several fast catastrophic events predating the closure of the basin and its deformation. This level consists of slide-blocks surrounded by monomict pebbly-mudstones and pebbly-sandstones. Among the slide-blocks, the biggest one consists of quartz-monzonites and leucocratic granodiorites of Late Permian age (260.8 \ub1 2.2 Ma) dated by zircon LA-ICP-MS method. By comparison with the regional data, the source area of these granitoids can be identified in the Istanbul-Zonguldak terrane. This evidence suggests a new picture for the paleogeographic setting of the ultimate stage of the continental collision between the Istanbul-Zonguldak and the Sakarya continental margins. In this scenario the coarse-grained deposits of the Tarakl\u131 Flysch are supplied by an orogenic wedge, consisting of oceanic units topped by the Istanbul-Zonguldak terrane. This orogenic wedge represented the north side of the foredeep, while the southern one was represented by the still undeformed Sakarya continental margin

Geology of the Northwestern Krania Basin

The Greveniotiki Pindos Mountains of Greece showcases the tectonics affecting the Central Mediterranean; however no detailed geological maps have been produced of the region. In this study we present a 1:10000 geological map of Mount Orliakas and its surrounding areas, including westernmost parts of the Pindos Ophiolite complex and the Mesohellenic basin. We also provide new lithological, structural, and palaeontological discussions of the region and give new evidence for the provenance of the Kranea Formation

Déformation des unités métamorphiques de haute pression de la subduction à l'exhumation. (Exemple des Cyclades, Grèce)

Highpressure-­‐lowtemperaturemetamorphicrocksarewitnessofthebehaviourofsubductionzonesatlithospherescale.Theserocksundergoprogradeandretrogrademetamorphismduringburialandexhumation,respectively.Duringexhumation,deformationevolvesfromductiletobrittle.ThepresentthesisconsistsinananalysisofthesuccessivedeformationsrecordedbytheCycladicBlueschistUnit(CBU)inGreeceduringasubduction-­‐exhumationcycle,intheframeoftheAegeanback-­‐arcextension.ThestudyofductiledeformationsrecordedbytheCBUwasusedtoseparatethoseassociatedtoburial,duringsubduction,fromthoserelatedtoexhumationandtocharacterisetheirkinematicsintheframeoftheAegeanextensiondynamics.Arestorationofpost-­‐12MadeformationsshowsthatinearlytomiddleMiocenedeformationisduetoonlyonedetachment(theNorthCycladicDetachment)controlledonlyonecorecomplex(theCentralCycladesCoreComplex).Laboratoryexperimentsonsmall-­‐scalemodelshavebeenusedtoarguethatAegeanextension,since12Ma,resultedfromaninteractionbetweentheHellenicsubductionretreattowardtheSWandthewestwarddisplacementofAnatoliaatleast7yearsearlierthanwhatwasthoughtuptonow.ThefoldeddomainofthecentralCycladesisadirectwitnessofthisinteraction.TheexperimentsalsoshowthattheVardarsuturehasplayedanimportantlocalisingroleinthisprocessasapre-­‐existingweakzoneLesrochesmétamorphiquesdehautepression–bassetempératuresontdestémoinsdufonctionnementdeszonesdesubductionàl’échelledelalithosphère.Lorsdeleurenfouissementcesrochessubissentunmétamorphismeprograde,puisretrogradependantleurexhumation,etuneévolutiondesdéformationsdeductilesàfragiles.Cettethèseprésenteuneanalysedesdéformationssuccessivesenregistréesparl’unitédesSchistesBleusCycladiques(SBC)enGrècependantuncyclesubduction-­‐exhumation,danslecadredel’extensionarrière-­‐arcduDomaineEgéen.L’étudedesdéformationsductilesenregistréesparlesSBCapermisdedistinguercellesassociéesàl’enfouissement,pendantlasubduction,decellessynchronesdel’exhumationetdecaractériserleurcinématiquedanslecontextedynamiquedel’extensionégéenne.Unerestaurationdesdéformationspostérieuresà12Mamontrequel’extensionMiocèneinférieuràmoyenn’estduequ’àunseuldétachement,leDétachementNordCycladique,contrôlantledéveloppementd’unseuldômeextensif,leCoreComplexdesCycladesCentrales.Desexpériencesdelaboratoiresurmodèlesréduitsontpermisd’argumenterqueladéformationégéenne,depuis12Ma,résultaitd’uneinteractionentreleretraitversleSWdelasubductionHelleniqueetledéplacementversl’ouestdel’Anatolie,aumoins7Maplustôtqu’onlepensaitjusqu’àprésent.LazoneplisséeducentredesCycladesenestuntémoingéologiquedirect.LesexpériencesontaussimontréquelasutureduVardarajouéunrôleimportantdansceprocessus,entantquezonedefaiblessemécanique

Eratosthenes Seamount: an oceanographic yardstick recording the Late Mesozoic-Tertiary geological history of the Eastern Mediterranean.

Three boreholes were drilled on the northern slope of the Eratosthenes Seamount during Leg 160. Lithological data were obtained back to the Early Cretaceous. Lithological correlation of shallow-marine sedimentary rocks reveals similarities in the Lower Cretaceous lithological successions of the Eratosthenes Seamount with the southern Levant passive margin. Bathyal chalks of Coniacian-Maastrichtian to middle Eocene age recovered from the Eratosthenes Seamount at Site 967 are also comparable with similar sedimentary units in the Levant. Both the southern margin of the Levant basin and the Eratosthenes Seamount subsided to bathyal depths during Late Cretaceous-Paleogene time. These correlated successions differ from contemporaneous units in southern Cyprus that are dominated by the Upper Cretaceous Troodos ophiolite and its deep-sea sedimentary cover. The presence of shallow-marine limestones of Miocene age on the Eratosthenes Seamount indicates uplift before, or during, the Miocene, whereas the overlying Pliocene-Pleistocene successions comprise unlithified hemipelagic sediments that accumulated in deeper water following tectonic subsidence. Previously obtained geophysical data suggest that the Eratosthenes Seamount has variable crustal characteristics. Seismic refraction data reveal an intermediate crustal layer of seismic velocity of 6.1-6.3 km/s beneath the seamount, which also extends under Cyprus, but then wedges out southward under the Levant basin. A large magnetic anomaly that underlies the seamount and its perimeter was previously correlated with the Troodos ophiolite. However, seismic reflection profiles reveal the existence of an important northward-dipping thrust fault separating Cyprus from the Eratosthenes Seamount. Taken together, the geophysical and geological evidence indicate that the tectonic evolution of the Eratosthenes Seamount is linked to that of the North African continental margin from early Mesozoic time onward. The seamount was in a shallow-marine depositional setting in the Early Cretaceous, then subsided to bathyal depths in the Late Cretaceous. It was later uplifted, as indicated by the Miocene shallow-marine limestones recovered from Sites 965 and 966. Then, during Pliocene-Pleistocene time, the Eratosthenes Seamount was thrust beneath Cyprus because of collision of the African and the Eurasian plates

Rapid spatiotemporal variations in rift structure during development of the Corinth Rift, central Greece

The Corinth Rift, central Greece, enables analysis of early rift development as it is young (<5Ma) and highly active and its full history is recorded at high resolution by sedimentary systems. A complete compilation of marine geophysical data, complemented by onshore data, is used to develop a high-resolution chronostratigraphy and detailed fault history for the offshore Corinth Rift, integrating interpretations and reconciling previous discrepancies. Rift migration and localization of deformation have been significant within the rift since inception. Over the last circa 2Myr the rift transitioned from a spatially complex rift to a uniform asymmetric rift, but this transition did not occur synchronously along strike. Isochore maps at circa 100kyr intervals illustrate a change in fault polarity within the short interval circa 620-340ka, characterized by progressive transfer of activity from major south dipping faults to north dipping faults and southward migration of discrete depocenters at ~30m/kyr. Since circa 340ka there has been localization and linkage of the dominant north dipping border fault system along the southern rift margin, demonstrated by lateral growth of discrete depocenters at ~40m/kyr. A single central depocenter formed by circa 130ka, indicating full fault linkage. These results indicate that rift localization is progressive (not instantaneous) and can be synchronous once a rift border fault system is established. This study illustrates that development processes within young rifts occur at 100kyr timescales, including rapid changes in rift symmetry and growth and linkage of major rift faults

Seismicity and associated strain of central Greece between 1890 and 1988

We examined the seismicity of central Greece between 1890 and 1988, using macroseismic and instrumental data, to ask two questions: (1) does the seismicity of this period reveal all the major tectonic structures that are known to be active?; and (2) what are the likely strains associated with the seismicity over this period? Many known active structures have been effectively aseismic for the last hundred years, and even the inclusion of all known large events earlier than 1890 reveals no activity associated with the NE coast of Evia, Gulf of Argos, or graben NE of Mt Parnassos. It is clear that even 100 years' data are inadequate for either a reasonable assessment of seismic risk or for a confident estimation of maximum magnitude. However, we are aware of no earthquakes in central Greece during the last 200 yr that were larger than Ms 7.0. It is probable that the maximum magnitude is restricted by the maximum length of fault segments, which appears to be around 15-20 km. The earthquakes of Ms ≥ 5.8 during 1890-1988 can account for a N-S displacement of around 45-70 cm (with maximum and minimum estimates a factor of two greater and smaller than this) across part of a 1890-1900 triangulation network in central Greece that was resurveyed in 1988. The contribution of smaller events may increase this displacement by about 50 per cent. This cumulative seismic displacement is similar to that estimated from the geodetic work (about 100 cm), but a detailed comparison of the two sets of observations will be reported elsewhere. A re-evaluation of all the important earthquakes of 1890-1988 in central Greece is presented in the Appendix, which summarizes information of use to both earth scientists and engineers

CRITICAL METALS IN GREECE: MINERALOGICAL AND GEOCHEMICAL IMPLICATIONS IN CHALKIDIKI, ANAFI, MILOS AND LAVRIO

Η σπουδαιότητα της εύρεσης κρίσιμων μετάλλων αυξάνεται, λόγω της αναγκαιότητάς τους στη σύγχρονη τεχνολογική βιομηχανία. Η Ελλάδα θα μπορούσε να διαδραματίσει σημαντικό ρόλο σε αυτό, διότι στο μέλλον θα έχει την ικανότητα να προμηθεύει αυτές τις κρίσιμες πρώτες ύλες, καθώς φιλοξενεί μεγάλο αριθμό αποθέσεων με μεταλλεύματα. Ο ορυκτός πλούτος της Ελλάδας να συμβάλει σημαντικά σε μια ανταγωνιστική και βιώσιμη οικονομία λόγω αυτώ των αποθέσεων. Στόχος της μελέτης αυτής είναι να προσδιοριστεί αν μπορούν να βρεθούν κρίσιμα μέταλλα στις Μαύρες Πέτρες (Χαλκιδική), στην Πλάκα (Λαύριο), στην Ανάφη και στη Μήλο μέσα στο σφαλερίτη, το γαληνίτη και τα τελλουρίδια. Η μελέτη επικεντρώθηκε κυρίως στο αντιμόνιο (Sb), το βισμούθιο (Bi), το κοβάλτιο (Co), το κάδμιο (Cd), το γάλλιο (Ga), το γερμάνιο (Ge), το ίνδιο (In), το σελήνιο (Se) και το τελλούριο (Te). Οι αναλυτικές μέθοδοι που χρησιμοποιήθηκαν ανίχνευσαν υψηλές συγκεντρώσεις κοβαλτίου στην Ανάφη μέσα στο πλέγμα, κυρίως του σφαλερίτη και του γαληνίτη. Υψηλές συγκεντρώσεις αντιμονίου υπάρχουν στο Λαύριο. Εκτός από το Λαύριο, βρίσκεται μέσα στο γαληνίτη στις Μαύρες Πέτρες και στην Ανάφη. Το Βισμούθιο παρουσιάζει υψηλές συγκεντρώσεις στο Λαύριο, κυρίως μέσα στο γαληνίτη. Το κάδμιο και το γάλλιο παρουσιάζουν υψηλές συγκεντρώσεις στη Μήλο μέσα στο σφαλερίτη και στο γαληνίτη, αντίστοιχα. Το γερμάνιο έχει υψηλές συγκεντρώσεις στην Ανάφη και το ίνδιο στις Μαύρες Πέτρες, και οι δύο εντός του σφαλερίτη. Στην Ανάφη και στη Μήλο το σελήνιο μπορεί να ανιχνευθεί μέσα στο σφαλερίτη και στο γαληνίτη, αντίστοιχα. Τέλος, το τελλούριο είναι κυρίως στη Μήλο μέσα στα τελλουρίδια.The importance of discovering critical metals is growing, due to their necessity in the modern high technological industry. Greece could play an important role in this because in the future it has the ability to supply these critical metallic raw materials, as it hosts a large number of ore deposits. Many of these deposits are promising targets for future exploitation and exploration so that the mineral wealth of Greece can make a significant contribution to a competitive and sustainable economy. This study aims to determine if critical metals can be found in Mavres Petres (Chalkidiki), Plaka (Lavrio), Anafi and Milos islands inside sphalerite, galena and telluride minerals. The focus was mainly in antimony (Sb), bismuth (Bi), cobalt (Co), cadmium (Cd), gallium (Ga), germanium (Ge), indium (In), selenium (Se) and tellurium (Te). The analytical methods used have detected high cobalt concentrations in Anafi inside the lattice mostly of sphalerite and galena. High antimony concentrations are present in Lavrio. Apart from Lavrio, it is found inside galena in Mavres Petres and Anafi. Bismuth shows high concentrations in Lavrio, mostly inside galena. Cadmium and gallium show high concentrations in Milos island inside sphalerite and galena, respectively. Germanium has high concentrations in Anafi and indium in Mavres Petres, both inside sphalerite. In Anafi and in Milos islands selenium can be detected inside sphalerite and galena, respectively. Finally, tellurium is mostly in Milos island inside the telluride minerals