Mikhail Rogov's current research


Callovian/Oxfordian boundary beds of the Russian Platform (in join with Dr. D.N. Kiselev)

            Now we have prepared for publication monograph concerning ammonite faunas and biostratigraphy of the Middle Callovian lowermost Lower Oxfordian of the Russia . Summary of the ammonite faunal horizons were represented as a poster on the 32nd Geological Congress [see publications list]. Additional excavations undertaken during the summer of 2004 shows possibility of the more precise determination of the faunal horizons both new (as mojarowskii horizon) and earlier known from the Western Europe. We try to compose parallel scales of the horizons based on the development of the different phylogenetic lineages (most important are lineages of Subboreal kosmoceratids and Boreal cardioceratids). 


Oceanic ammonoids of the northern Siberia from the Jurassic/Cretaceous boundary beds (in join with A.A. Igolnikov)

            So-called oceanic ammonoids (phylloceratids, lytoceratids and Bochianites) are the little-known fossils from the Upper Jurassic lowermost Cretaceous of the Arctic areas. There are few levels with the numerous oceanic ammonoids (middle part of the Upper Volgian Okensis Zone; sometimes Kochi Zone and uppermost Mesezhnikovi Zone of the Ryazanian). Interpretation of these levels and events still remain questionable. Due to resemblance of the Siberian ammonoids with Pacific ones (Californian and Alascan species described by R.Imlay) we can make preliminary conclusion about the good marine connection between Arctic and Pacific basins during the time spans of the cephalopod migrations.

Boreiophylloceras sp. from the Ryazanian-Valanginian boundary 

beds of the Paksa Peninsula (N.Siberia)


The Volgian Stage of the Middle Volga area and adjacent regions (in join with Dr. D.N. Kiselev, Dr. O.S. Dzyuba, Dr. E.M. Tesakova, Dr. G. Price)

            Ammonite faunas of the Volgian Stage now are under intensively investigation of me and Dr. Kiselev. Major conclusions: 1. Lower Volgian succession of the Volga area consist from the succession of the faunal horizons of good correlative potential with both Boreal and Tethyan scales. Gradual changes within the Ilowaiskya Pseudovirgatites - Zaraiskites lineage denied the presence of the gap between Lower and Middle Volgian. 2. Nikitini and Fulgens Zones further may be subdivided on the some faunal horizons with assemblages suggested gradual transition (and also absence of a remarkable gap) between Middle and Upper Volgian . Our colleagues now studied the systematics of the belemnite guards (Dr. O.S. Dzyuba), ostracods (Dr. E.M. Tesakova) and analyze stable isotope composition of the belemnite rostra (Dr. G. Price). 


Tithonian ammonites & biostratigraphy of the Crimea (in join with Dr. V.V. Arkadiev)

            In spite of the numerous articles with the lists of the Tithonian ammonites from Crimea were published at the last decades, hitherto only few ammonoids were figured and described. Zonal scheme of the Crimean Tithonian used recently during the geological survey based on the partly incorrect ammonite determinations. For example, both Lithacoceras ulmense and Kossmatia  richteri points from the Hybonotum Zone of the Baidar Valley . Complex tectonic structure and scarcity of the ammonite records make difficulties for the creation of the new ammonite scale. Now we are in the beginning of the pathway for the studying of Crimean Tithonian.



Franconites cf. vimineus (Schneid), Lower Volgian

~ boundary of the Sokolovi and Pseudoscythica Zones, Gorodishchi section





Middle Jurassic Lower Cretaceous Coleoids (excl. Belemnitida) from the Russia (in join with Dr. V.A. Bizikov)

            Non-belemnitid coleoids of the Russia now is one of the least studied fossil groups among fossil Cephalopods. Our field & office studies gave an abundant data concerning these fossils. Macrofaunal remains include among others gladii of the Trachyteuthis (Volgian) and Plesioteuthis (Aptian), numerous phragmocones presumable of Acanthoteuthis (occurred from Lower Callovian till Hauterivian in the area between Moscow and northern Siberia ). Microfossil remains comprise coleoid statoliths and microonychites of the Jurassic age. 



Acanthoteuthis sp., Middle Volgian Panderi Zone, 

presumably regularis horizon of the Orlovka  (Saratov Volga area)



Ecostratigraphical approach and changes in the molluscan communities during the latest Kimmeridgian early Middle Volgian of the Central Russian Sea

            Field works of the 2003 gave an abundant data about the changes of the ammonite spectra as well as ammonite/macrobenthos ratio in the some Kimmeridgian-Volgian section (Gorodishchi, Khanskaya gora, Lake Elton ). Increase of the amount of Tethyan ammonoids in the faunal associations, as a rule, coincides with the common increase in a variety of mollusks (especially cephalopods) and, most likely, corresponds to the moments of the sea level rising. For macrofaunistic associations of the internal seas typically absence of oceanic ammonoids (such as Phylloceratida and Lytoceratida) and prevalence of benthonic organisms (ammonoids/macrobenthos ratio usually fluctuate within 5-15%). On structure of the described assemblages influence rendered first of all not in themselves eustatic events, but presence / absence of the geographical barriers supervised by regional tectonics. Significant influence on the ammonite associations of the Northern Eurasia had global sea level rising during the Middle Tithonian (latest Early Volgian neoburgense hemera and ? Pectinatus Chron). At this time numerous Tethyan ammonoids (mainly Anaspidoceras and Sutneria) have penetrated into the Central Russian Sea (Neoburgense Event). At the same time transgressive impulse, followed by the mass spread of the Boreal Pectinatites everywhere in Siberia , fixed in the Arctic region.  





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