New data on ammonites and stratigraphy of the uppermost Kimmeridgian – lowermost Volgian of the Middle Volga region (Russia)

• Autorzy: Mitta V. , Scherzinger A.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

New collections at the boundary of the Kimmeridgian and Volgian from the Volgian Stage lectostratotype section nearby Gorodishche (central Russia) make it possible to give a general view on the stratigraphic distribution of some of the important ammonite taxa. For the first time Sutneria eumela (d’Orbigny) and Sutneria subeumela Schneid from the Upper Kimmeridgian are illustrated, and Aulacostephanus volongensis Khudyaev is recognized. The latter is the macroconch of Aulacostephanus undorae (Pavlow). These discoveries indicate the chronostratigraphic correlation between the Eudoxus and Fallax zones of the Russian Platform and the Pseudomutabilis and Beckeri zones of the Submediterranean region. “Discosphinctoides” subborealis Kutek & Zeiss is placed in the genus Sarmatisphinctes Kutek & Zeiss and “Glochiceras (Paralingulaticeras)” efimovi Rogov belongs to a new ammonite genus. In the beginning of the Volgian a strong faunal provincialism has been perceptible which makes correlations with areas outside the Russian Plate and Central Poland more difficult. The lowermost part of the Lower Volgian (Klimovi Zone) seems to be time equivalent at least in part, if not wholly, of the Upper Kimmeridgian. Because of different interpretation of the Autissiodorensis Zone Ziegler 1962 in the localities of West Europe and the Russian Platform we give the priority to the term Fallax Zone Ilovaisky 1941. The name “Autissiodorensis Subzone” does not seem the best choice for the lowermost Subzone of the Fallax Zone of the Russian Kimmeridgian. Up to now no figured specimen of A. autissiodorensis from the Russian Platform has been indicated. According to our opinion the best index fossil for the base of the Fallax Zone in the area of study seems to be Amoeboceras volgae (Pavlow), and we recommend using the term Volgae Subzone in future. More information about results of our study are given in Scherzinger and Mitta (in press).

Słowa kluczowe

EN

ammonites; stratigraphy; Upper Kimmeridgian; Lower Volgian; Volga Region; Russia

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 191--192
• Opis fizyczny: Bibliogr. 1 poz.

Twórcy

autor

Mitta V.

autor

Scherzinger A.

• Paleontological Institute Russian Academy of Science, Profsoyuznaya 123, Moscow, 117997 Russia,

Bibliografia

• Scherzinger A. and Mitta V. In press. New data to ammonites and stratigraphy of the Upper Kimmeridgian and Lower Volgian (Upper Jurassic) of the middle Volga Region (Russia). Neues Jahrbuch für Geologie und Paläontologie Abhandlungen.