RUSSIAN PLATE AS A KEY REGION FOR THE VOLGIAN/TITHONIAN CORRELATION: REVIEW OF THE MEDITERRANEAN FAUNAL ELEMENTS IN THE

Since the 70es of the XX century records of some Mediterranean ammonites, such as Oppeliidae, Haploceratidae, Aspidoceratidae etc., from the uppermost Kimmeridgian to the lowermost Middle Volgian of the Russian Plate have been known (Mesezhnikov et al., 1977). Unfortunately, these data are practically not used for the Boreal-Tethyan correlation. In the uppermost Kimmeridgian of the Russian Plate (Autissiodorensis Zone) we can recognize a succession of Oppeliidae (the same in SW Germany). In the lower part of Autissiodorensis Subzone there appears Metahaploceras subnudatum, the upper part of those marked by the apparition of Metahaploceras cf. zlatarskii sensu Schweigert, 1998. In the uppermost Fallax Subzone Metahaploceras rebouletianum fridingense (-Neochetoceras rebouletianum: Schweigert, 2000, pi. 2, fig.5) is common. Unfigured Metahaploceras cf. rebouletianum was also cited from the Upper Kimmeridgian of the North Subcaspian region (Bogdanov, 1934). Following these data, we can correlate the base of Tithonian with the base of Volgian (Fig.l). In the lower Klimovi Zone (beds with Neochetoceras steraspis and Glochiceras (Lingulaticeras) solenoides} N. steraspis and G. (L) solenoides are very common, as well as in the riedlingense horizon of SW Germany. The following lithographicum Efimovi horizon contains numerous Glochiceras (Paralingulaticeras) spp., and mor