Geology and stratigraphy of Istanbul region

Abstract

ABSTRACT The Istanbul region is a part of a bigger continental fragment called the Rhodope-Pontide Fragment. Within this continental fragment, the Istanbul Zone consists, at the base, of a Neoproterozoic middle to high-grade crystalline rocks with relicts of volcanic arc and continental crust, which are not observed in Istanbul itself, but farther east near Zonguldak. This basement is overlain by a continuous, well-developed sedimentary sequence extending from the Lower Ordovician to the Lower Carboniferous. The Carboniferous flysch marks the progress of a shortening event. This event led to the folding and faulting of the Palaeozoic sequence which was intruded by an uppermost Permian granitoid and unconformably overlain by the Upper Permian to Lower Triassic red sandstones and conglomerates. The Triassic series is better formed east of Istanbul showing a typical transgressive development. The Jurassic sequence is absent, most likely as a result of the closure of the Palaeo-Tethys and the resultant genera...