V.A. Viginsky

Late Alpine tectonic reconstruction OF eastern Mezotethys west Part (Black Sea region)

Azov and Black Sea basin originated in the western part of the eastern Mezotethys. Eurasian and Arabian geoplates were together with the intervening Rodopian-Pontian suture during Mid-Late Cretaceous. There is blueschist belt occurs immediately south of this suture in northwest Turkey (A.I. Okay et al., 1998). The above-mentioned suture is marked by the marginal plate areas, which composed by collisional blocks of the transitional crustal type. They are composed of the Laramide effusives, covered by slightly deformed Cenozoic sedimentary blanket on the Eurasian plate and by the Laramide rootless ophiolites overthrust on the Anatolian plate structures.

Regionally there is a geostructural number: Pannonian depression - West-Black Sea hollow - East-Black Sea hollow - South-Caspian hollow, describes as development stages of rift tectonic mode within the thin crust Middle-European zone. So, if the Pannonian depression has stable rift neotectonic mode (Grachev, 2000), the West-Black Sea depocentre is characterised by pre-rift tectonic mode (in term of Grachev, Devyatkin, 1996), and East-Black Sea - South-Caspian hollows – by abyssal neotectonic mode (Viginsky, 2002). This zone was caused by post back-arc plum activity, which first spike had beginning at early Cenozoic (65 m. y.), and others - at late Eocene and Middle Miocene. Last cycle of plum activity correlates with vulcanites of rift type, locates along the Arkhangelsky-Andrusov lineament and outcrops near Van-lake (Koronovsky et al., 1999). Such activity is accompanied by low density of upper mantle and by its anisotropy.