Türkiye Jeoloji Bülteni

Geology of the Kastamonu Region and Geological Constraints for the Evolution of the Paleotethyan Domain

Abstract: Daday-Devrekani massif consists of metamorphic rocks of the European margin that are progressively sliced with slivers of oceanic crust emplaced prior to Aptian, and with the concurrent Cretaceous flysch. The uppermost slice consists essentially of Paleozoic sediments and Karakaya formation intruded by Early Jurassic granites. These are covered, post-tectonically, by a carbonate-flyschwedge of the back-arc basin, deposited on teh north-facing platform of the Black Sea, in the interval of Late Liassic to Lutetian.The overall solution for the Gondwana-Eurasia convergence frame seems to be constrained with the idea that a thin sliver of continental crust was rifted off the northern Gondwana during the Early Triassic and was progressively accreted to Europe by Early Tertiary.Paleogeographic setting of the Paleotethyan domain with respect to the Pontides seems a very significant point for elucidation of the evolutionary frame. Southward deepening paleomorphology of the Pontides for the Permo-Carboniferous period, restriction of the Karakayaformation (Permo-Triassic) to northern side of the Îzmir-Kars suture in addition to its being adjacent to the suture, suggest presence of anoceanic domain between Anatolids and Pontides for the late Paleozoic and earlier. A carbonate flysch wedge, being restricted to north of the suture and covering, post-tectonic ally, the Karakaya (Akgöl) formation, indicates very clearly that it is related to teh back-arc batin(The Black Sea) and not to the northern strand of Neotethys of Şengör and Yılmaz (1981).The ocean floor between the subduction zone and the edge of the continental crust, must have been retrocharriaged onto the European margin, very likely through the aid of paleo-transform faults. The consumption of the Paleotethys could be realised by a multi-stageand/or progressive recess of the subduction zone. The island arc also retreated accordingly. The old island arc system was up warped due tothe compression of the new system and was covered, post-tectonically, by the sediments of the back-arc basin. The compressive regimealso migrated southwards in accordance with the new island arc system and the elevated flysch provided sediments for the new fore-arc basin. Daday region is probably a good example of a continental margin that shows progressive folding and imbricate slicing of the deformed rocks with flysch sediments deposited concurrently.It may be outlined that the Paleotethyan domain, diving north under Eurasia, was consumed progressively between PermoCarboniferous and Early Tertiary.