New Stratigraphic and Palaeogeographic Results from the Palaeozoic and Early Mesozoic of the Middle Pontides (Northern Turkey) in the Azdavay, Devrekani, Kre and Inebolu Areas: Implications for the Carboniferous - Early Cretaceous Geodynamic Evolution an
The Kre Complex of the Middle Pontides, northern Turkey, isnot a remnant of the Palaeotethys but consists of three different unitswith differing geological history, the Kre Ridge Unit, the KreOcean Unit and the ala Unit. The Kre Ridge Unit consists of theServeay Group, a pre-Permian, low-grade metam...
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Veröffentlicht in: | Geologia Croatica 2000-12, Vol.53 (2), p.209-268 |
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Sprache: | eng |
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Zusammenfassung: | The Kre Complex of the Middle Pontides, northern Turkey, isnot a remnant of the Palaeotethys but consists of three different unitswith differing geological history, the Kre Ridge Unit, the KreOcean Unit and the ala Unit. The Kre Ridge Unit consists of theServeay Group, a pre-Permian, low-grade metamorphic Variscanoceanic sequence, and the Sõralõk Group, a Lower and Middle Triassicshallow-water sequence of North Alpine facies and event successionwhich disconformably overlies the Serveay Group. Following ahiatus, the Sõralõk Group is overlain by marginal parts of the AkglGroup with olistoliths of local origin which were derived mainly fromthe Sõralõk Group. The Kre Ocean Unit consists mostly of theAkgl Group (siliciclastic turbidites and olistostromes of the Karadagù tepe Formation, which is a middle Carnian to Middle Jurassicaccretionary complex from the southern, active margin of the KreOcean, and mainly Middle Jurassic molasse type shallow-water sandstones,siltstones and shales of an unnamed formation) and of thickoceanic basalts (Ipsinler Basalt). Tectonic slices of Middle Triassic tolower Carnian ophiolites and basalts are also present. The Karadagù tepe Formation contains numerous Middle Triassic exotic olistolithsand blocks of shallow-water and predominantly slope and basinallimestones, ocean-floor deep-sea sediments (shales and radiolarites),basalts and small clasts of ophiolites or ophiolitic detritus. Theala Unit consists of deposits from the northern, passive margin ofthe Kre Ocean with many Pelsonian to upper Norian Hallstatt Limestonesand Rhaetian -Lower Jurassic (?Middle Jurassic) deep-watershales and marls. All three units are overlain following a period ofnon deposition by the Upper Jurassic Brnk Formation (red conglomerate,sandstone) and Inaltõ Formation (shallow-water platformcarbonates).The Kre Ridge Unit was split away from the Variscan SakaryaContinent by the opening of the Karakaya oceanic rift basin duringlatest Permian (Dorashamian) and became a continental splinterbetween the Karakaya oceanic rift basin and the Kre Ocean (openedduring the late Scythian).Southward subduction began in the Kre Ocean during the middleCarnian (beginning of the Karadagù tepe siliciclastic turbidites),whereas at the northern passive margin the deposition of HallstattLimestones continued until the latest Norian. The deposition of siliciclasticturbidites and olistostromes (Diskaya Unit) began in the entireKarakaya oceanic rift basin during the middle Carnian, |
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ISSN: | 1330-030X 1333-4875 |
DOI: | 10.4154/GC.2000.03 |