Late Sarmatian mammal localities of the Eastern Paratethys: Stratigraphic position,magnetochronology, and correlation with the European continental scale

Analysis of geological sections, paleogeography, and paleomagnetic data is used to reveal succession of the middle to late Sarmatian mammal localities of the Eastern Paratethys and their correlation with the continental stratigraphic scale of Western Europe. Until recently, the late Sarmatian localities were correlated with MN10 and even MN11 zones. As is proved, all the known late Sarmatian localities should be correlated with the upper half of Zone MN9. The terminal late Sarmatian faunas only, which are correlative with the lowermost Chron C4Ar3r and older than 9.6 Ma, can be referred to Zone MN10. According to essential changes in taxonomic composition of faunas from continental localities around the Eastern Paratethys, which are recorded in the mid-late Sarmatian, Zone MN9 can be divided in two subzones MN9a and MN9b separated by boundary at ～10.5 Ma. The refined correlation can be used to establish difference between faunas of the Southeastern, Central, and West European paleozoogeographic provinces and to assess diachronism in dispersal of mammals. In the Southeastern province, many forms characteristic of the Turolian in Central and Western Europe first appeared as early as in the mid-Vallesian. The results obtained indicate that faunal criteria used to define boundaries of MN zones in Western Europe are of a regional importance being inapplicable to the entire North Eurasia and even to Europe as a whole that is unfortunately ignored by many paleontologists. Criteria of distinction should be worked out for each paleozoogeographic province. As geochronological levels of faunal changes are identical throughout the northern Palearctic, they suggest impact of global factors despite variable manifestation in different regions.     

Astronomically-tuned cyclicity in Upper Maeotian deposits of the eastern paratethys (Zheleznyi Rog section,Taman)

Astronomically-tuned cyclicity in Upper Maeotian deposits of the Zheleznyi Rog section (Taman, Eastern Paratethys) was revealed first time using the methods of cyclostratigraphy. According to the spectral analysis of the data on the magnetic susceptibility of rocks and basing on the peaks of Lomb-Scargle and REDFIT periodograms, cyclicity with a length of 7.1–8.9 m was established in studied deposits. These cycles are comparable with the period of oscillations of the Earth’s axis angle to the plane of its orbit, which corresponds to 41000 years. The data we obtained confirm the idea of the correlation of Upper Maeotian deposits to the greater part of the Chron C3An and duration of the late Maeotian no longer than 700000–750000 years.     

Age of the Vallesian lower boundary (Continental Miocene of Europe)

The Vallesian lower boundary and “Hipparion-datum” are estimated as ranging in age from 11.2 to 10.7 Ma in Central to Western Europe and Western Asia. Judging from complete sections of Sarmatian marine sediments in the Tamanskii Peninsula and Transcaucasia with known paleomagnetic characteristics, the above dates correspond to the lower upper Sarmatian (Khersonian) of the Eastern Paratethys, although in Moldova and Ukraine the earliest hipparion remains are associated with the middle Sarmatian (Bessarabian) sediments. The normally magnetized middle Sarmatian deposits in hipparion localities of Moldova are correlative with an upper part of Chron C5An (upper boundary 11.9 Ma old) or, less likely, with Subchron C5r2n (base 11.5 Ma old). Consequently, the first occurrence of hipparions in southeastern Europe is recorded in the Middle Miocene, i.e., 0.7 m.y. (or 0.3 m.y.) earlier than the date of 11.2 Ma formerly accepted for the Vallesian lower boundary in Europe. Possible reasons for disagreements in age determination of the Vallesian base are discussed.     

The upper Bajocian-Lower Bathonian of Pechora River basin and Boreal-Tethyan correlation

Distribution of ammonites in the Bajocian-Bathonian boundary beds of the Izhma River basin is considered. A new scheme of zonal subdivisions suggested for the Pechora basin includes the Arctocephalites arcticus Zone of the upper Bajocian and the Arctocephalites greenlandicus-Arcticoceras ishmae Zone of the lower Bathonian. The Dreshchanka Formation age (late Bajocian-early Bathonian) and the commencement time of the Boreal sea transgression (Late Bajocian) are specified. Correlation of the Bajocian-Bathonian boundary strata of the northern Caucasus, central and northern Russia with stratigraphic scales of Western Europe and East Greenland are discussed. New infrazonal subdivisions, i.e., the faunal horizons, are described. As is shown, the parkinsoni-zigzag zonal boundary accepted to be the Bajocian-Bathonian boundary in standard scale corresponds to boundaries separating the michalskii and besnosovi zones in the Lower Volga region and the arcticus and greenlandicus zones in the Boreal areas.     

欧洲和远东第四纪陆相堆积的生物地层对比(哺乳动物)

在晚第三纪晚期和第四纪时, 欧亚大陆古动物群的面貌受两个陆桥的影响很大, 在尽西边有一个复合陆桥, 即非洲与欧洲相连, 与亚洲沿着非洲西边—伊比利亚半岛连接;中间的非洲—西西里岛陆桥和一个东地中海陆桥(非洲—阿拉伯半岛)连接。     

The Yudomian of Siberia,Vendian and Ediacaran systems of the International stratigraphic scale

In Russia, the terminal Neoproterozoic formally includes the Vendian of western part of the East European platform and the concurrent Yudoma Group of Siberia. As is shown in this work, the designated subdivisions correspond in the stratotypes only to the upper, Yudomian Series of the Vendian. In the Siberian platform, the Ust-Yudoma and Aim horizons of the Yudomian are tightly interrelated. The lower of them, bearing remains of Ediacaran Fauna, represents the Ediacarian Stage, whereas the upper one containing small-shelled fossils (SSF) corresponds to the Nemakit-Daldynian Stage divided into the trisulcatus and antiqua superregional zones. In more complete sections of the platform periphery, sediments of these subdivisions conformably rest on siliciclastic succession that should be ranked as basal subdivision of the Yudomian. The succession is concurrent to the Laplandian Stage of the East European platform. According to geochronological dates obtained recently, the Yudomian Series spans interval of 600–540 Ma. In the East European platform, the Upper Vendian (Yudomian) begins with the Laplandian basal tillites of synonymous stage. In the west of the platform, tillites are dated at 600 Ma like the Upper Vendian base in Siberia. The next Ediacarian Stage of the East European platform is stratigraphic equivalent of the Redkino Horizon, while summary range of the Kotlin and Rovno horizons is concurrent to that of the Nemakit-Daldynian Stage. The Vendian of Russia is conformably overlain by the Tommotian Stage of the Lower Cambrian. Intense pre-Vendian events constrained distribution areas of the Lower Vendian sediments in Russia. The Lower Vendian deposits of the East European platform are most representative and well studied in the central Urals, where they are attributed to the Serebryanka Group. In Siberia, separate subdivisions representing the Lower Vendian are the Maastakh Formation of the Olenek Uplift, two lower members of the Ushakovka Formation in the Baikal region, and the Taseeva Group of the Yenisei Range. Chronological interval of the Lower Vendian corresponds to 650–600 Ma. The Marinoan Glaciation dated in Australia at 650–635 Ma is concurrent to basal part of the pre-Yudomian interval of the Vendian in Russia, whereas the Laplandian Tillite and Gaskiers Glaciation (600–580 Ma) correspond to onset of the Yudomian Epoch. The new Ediacaran System (Knoll et al., 2004) legalized in the International Neoproterozoic scale is close in range to the entire Vendian (635–544 Ma), although without basal beds (Marinoan Tillite) it deprives the terminal Neoproterozoic of its original sense. Inferiority of the system consists also in its indivisibility into stages. Hence, it is clear that the Vendian System subdivided in detail in Russia should be retained in the rank of terminal system of the Precambrian, one of the basic in general scale of the Neoproterozoic.     

Middle-Upper Miocene stratigraphy of the Taman Peninsula, Eastern Paratethys

The stratigraphy of the Taman Peninsula is defined using the sections at Zelensky Hill ?? Panagia, Popov Kamen, Taman and Zheleznyi Rog. The stratigraphy is constructed from distribution of mollusks, foraminifers, nannofossils, diatoms, and organic-walled phytoplankton, as well as incorporating paleomagnetic data. The occurrence of oceanic diatom species in the Middle-Upper Sarmatian, Maeotian and Lower Pontian makes a direct correlation possible between the sections studied, the Mediterranean basin and oceanic zonation. The new data on planktonic and benthic biotic groups suggests a pulsating connection of the Eastern Paratethys with the open marine basins, especially during transitional intervals within constant environments. Comprehensive studies of the Chokrakian-Kimmerian microbiota provide evidence for several levels of marine microbiotic associations that are related to short-term marine invasions. The biotic and paleomagnetic data of the Taman Peninsula sections give a more comprehensive, but sometimes a controversial picture on the Eastern Paratethys history and the nature of its relationship with the adjacent marine basins.     

Origin of gases dissolved in subsurface waters and paragenetic brines associated with saline strata

As a result of examining a large amount of information on stratotype sections of Neogene-Quaternary deposits of the south of Western Siberia, we have compiled a sequence through these deposits in which boundaries between geomagnetic subdivisions are linked with Pliocene-Quaternary biozones.

The Brunhes zone Includes deposits with mammal remains of the Upper Paleolithic, Khazara, and Tiraspol' assemblages. The Gauss-Matuyama inversion has been identified in the upper Pliocene deposits with a Khapry mammal assemblage. The lower boundary of the Gauss zone apparently passes below strata with a Moldavian faunal complex. The data on the biologic linking of the magnetic zones demonstrate the synchronous development of the faunal assemblages of Pliocene-Quaternary time in Western Siberia and in the southwest of European USSR. —Authors.     

A brief review of Agenian rhinocerotids in Western Europe

The Agenian is the earliest Neogene European Land Mammal Age. It encompasses the mammalian zones MN1 (23.03–22.7 Ma) and MN2 (22.7–20.0 Ma) and roughly coincides with the Aquitanian standard age. Agenian mammalian assemblages from Western Europe encompass a mixture of rhinocerotid taxa of Oligocene affinities and of Miocene newcomers, mostly recorded in France, Germany, Switzerland, and to a lesser extent, Spain. Rhinocerotidae are documented by seven species referred to five genera (Pleuroceros pleuroceros, Protaceratherium minutum, Plesiaceratherium aquitanicum, Mesaceratherium paulhiacense, Diaceratherium lemanense, D. asphaltense, and D. aginense), further attesting to a low suprageneric diversity. Their systematics, morphology, ecology, stratigraphical and geographical ranges are detailed in the present article. Occurrences and geographical ranges of all seven rhinocerotid species are illustrated on palaeogeographical maps of the circum-Mediterranean region at 23 Ma (MN1) and 21 Ma (MN2). The richest Agenian localities (Paulhiac, MN1; Laugnac, MN2) record a specific diversity similar to that of Orleanian rhinocerotid assemblages, with up to five/six associated species. All Agenian rhinocerotid species from Western Europe are endemic to the concerned region, which is consistent with the complete geographic isolation of Western Europe by earliest Miocene times. However, all five genera are documented by twin species in coeval localities of South and Central Asia, which implies (1) vicariant speciation events by latest Oligocene times and (2) the existence of intermittent pathways for terrestrial megamammals such as rhinocerotids during the concerned interval.     

New records of Dorcatherium guntianum (Tragulidae), stratigraphical framework, and diphyletic origin of Miocene European tragulids

Seven hitherto unpublished Dorcatherium guntianum teeth from the Early Miocene of Germany are described. Morphology and size of the teeth are documented in detail and taxonomic affiliation is assessed based on comparisons to type materials of European tragulids. The fossils represent one of the earliest European Dorcatherium records and the oldest unequivocal evidence of D. guntianum from Germany. A review of the European Dorcatherium occurrence pattern suggests that a bunoselenodont and a selenodont lineage immigrated into Europe simultaneously from the East or Southeast, and corroborates the interpretation of the genus as being diphyletic. Moreover, our data add support to immigration scenarios that have been linked with the emerging freshwater wetlands, which formed as a result of the regression in the Western Paratethys.     

Lower miocene sediments of the Maikop group in the Central Eastern Paratethys

The composite section of upper Maikop sediments compiled for the central part of the Eastern Paratethys is presented. The section (more than 1000 m) comprises the Karadzhalgan, Sakaraulian, and Kotsakhurian regional stages. The lower boundary of the Miocene drawn at the base of the Karadzhalgan regional stage is unambiguous only in the southern part of the central Ciscaucasia. In most areas of the Ciscaucasia, this boundary is drawn arbitrarily because of uniform lithology in the Oligocene-Miocene boundary interval and poor paleontological substantiation. Generally, the Maikop sequence is insufficiently studied and incomplete in many areas because of a discordant upper boundary of the Maikop Group. Nevertheless, materials presented in the paper characterize for the first time the composition and structure of the Lower Miocene sequence over a vast area of the Eastern Paratethys. The horizonwise reconstruction of Early Miocene basins has made it possible to reveal the major features of final stages in the formation of the Maikop clayey sequence.     

The upper Bathonian ammonite zonation of East Siberia

Modifications to the upper Bathonian zonal scale for northern East Siberia provided by the newly available paleontological record on Middle Jurassic reference sections in the Arctic regions of Yakutia and by the revised earlier collections, are justified. The oldest East Siberian members of Cadoceras are found to be characteristic not of the initial Callovian age as believed by Russian paleontologists, but of the terminal Bathonian age as was previously shown in the biostratigraphic scheme of East Greenland. The succession of zones and index species analogous to that of the latter is revealed in the studied region and the zonal boundaries in Siberia and East Greenland are inferred to be synchronous. Finds of Cadoceras calyx in the upper Bathonian scale permitted, for the first time, the recognition of a corresponding zone. The Bathonian-Callovian boundary is placed between the calyx and anabarense zones. The upper Bathonian zonal scale of northern East Siberia is now in total agreement with the East Greenland zonal scale.     

Upper Oligocene Sediments of the Ciscaucasus,Volga–Don,and Mangyshlak Regions (Central Eastern Paratethys): Communication 1. Main Compositional and Structural Features

Upper Oligocene sediments of the Eastern Paratethys are distinguished in the Maikop Group owing to several characteristic features. They form a thick (1000–1200 m) sequence with specific composition and structure in different structural–facies zones of the basin. The development of fish facies is the most remarkable feature. It includes unique sediments composed of fish bone detritus (FBD) and iron sulfides with high contents of REE, U, Sc, Re, Ni, Co, Mo, and other elements. These elements form commercial uranium–base metal deposits so far unknown in other formations of the Earth. The structure of thick rock sequences in the deepest part of the Eastern Paratethys is also characterized by specific features. Deep-sea clayey fish-facies sediments intercalate with beds of fine-grained sandy and silty material. Their influx into the central part of the basin was responsible for the clinoform structure of the rock sequence revealed by seismostratigraphic studies. This communication presents new data on the distribution of bone detritus deposits, composition and structure of sediments, and summary characteristics of Upper Oligocene sediments that are essential for the further analysis of facies–paleogeographic sedimentation conditions in the central Eastern Paratethys.     

A new magnetostratigraphic framework for the Lower Miocene (Burdigalian/Ottnangian, Karpatian) in the North Alpine Foreland Basin

Oligocene–Miocene chronostratigraphic correlations within the Paratethys domain are still highly controversial. This study focuses on the late Early Miocene of the Swiss and S-German Molasse Basin (Late Burdigalian, Ottnangian–Karpatian). Previous studies have published different chronologies for this time interval that is represented by the biostratigraphically well constrained Upper Marine Molasse (OMM, lower and middle Ottnangian), Upper Brackish Molasse (OBM, Grimmelfingen and Kirchberg Formations, middle and upper Ottnangian to lower Karpatian, MN 4a–MN 4b) and Upper Freshwater Molasse (OSM, Karpatian–Badenian, MN 5). Here, we suggest a new chronostratigraphic framework, based on integrated magneto-litho-biostratigraphic studies on four sections and three boreholes. Our data indicate that the OBM comprises chrons 5D.1r and 5Dn (Grimmelfingen Fm), chron 5Cr (lower Kirchberg Fm) and the oldest part of chron 5Cn.3n (upper Kirchberg Fm). The OSM begins during chron 5Cn.3n, continues through 5Cn, and includes a long reversed segment that can be correlated to chron 5Br. The OMM-OSM transition was completed at 16.0 Ma in the Swiss Molasse Basin, while the OBM-OSM changeover ended at 16.6 Ma in the S-German Molasse Basin. As the lower Kirchberg Fm represents a facies of the Ottnangian, our data suggest that the Ottnangian–Karpatian boundary in the Molasse Basin is approximately at 16.8 Ma, close to the 5Cr–5Cn.3n magnetic reversal, and thus 0.4 Myr younger than the inferred age of 17.2 Ma used in recent Paratethys time scales. Notably, this would not be problematic for the Paratethys stratigraphy, because chron 5Cr is mainly represented by a sedimentation gap in the Central Paratethys. We also realise, however, that additional data is still required to definitely solve the age debate concerning this intriguing time interval in the North Alpine Foreland Basin. We dedicate this work to our dear friend and colleague Jean-Pierre Berger (8 July 1956–18 January 2012).     

Evolution of the Central Asian Orogenic Supercollage since Late Neoproterozoic revised again

Revision of crustal architecture and evolution of the Central Asian Orogenic Supercollage (CAOS) between the breakup of Rodinia and assembly of Pangea shows that its internal pattern cannot be explained via a split of metamorphic terranes from and formation of juvenile magmatic arcs near the East European and Siberian cratons, followed by zone-parallel complex duplication and oroclinal bending of just one or two magmatic arcs/subduction zones against the rotating cratons. Also, it cannot be explained by breakup of multiple cratonic terranes and associated magmatic arcs from Gondwana and their drift across the Paleoasian Ocean towards Siberia. Instead, remnants of early Neoproterozoic oceanic lithosphere at the southern, western and northern periphery of the Siberian craton, as well as Neoproterozoic arc magmatism in terranes, now located in the middle of the CAOS, suggest oceanic spreading and subduction between Eastern Europe and Siberia even before the breakup of Rodinia at 740–720 Ma. Some Precambrian terranes in the western CAOS and Alai-Tarim-North China might have acted as a bridge between Eastern Europe and Siberia.The CAOS evolution can be rather explained by multiple regroupings of old and juvenile crust in eastern Rodinia in response to: 1) 1000–740 Ma propagation of the Taimyr-Paleoasian oceanic spreading centres between Siberian and East European cratons towards Alai-Tarim-North China; 2) 665–540 Ma opening and expansion of the Mongol-Okhotsk Ocean, collision of Siberian and East European cratons with formation of the Timanides and tectonic isolation of the Paleoasian Ocean; 3) 520–450 Ma propagation of the Dzhalair-Naiman and then Transurals-Turkestan oceanic spreading centres, possibly from the Paleotethys Ocean, between Eastern Europe and Alai-Tarim, essentially rearranging all CAOS terranes into a more or less present layout; and 4) middle to late Paleozoic expansion of the Paleotethys Ocean and collision of Alai-Tarim-North China cratons with CAOS terranes and Siberian craton to form the North Asian Paleoplate prior to its collision with Eastern Europe along the Urals to form Laurasia. Two to five subduction zones, some stable long-term and some short-living or radically reorganized in time, can be restored in the CAOS during different phases of its evolution.     

New sedimentological, bio-, and magnetostratigraphic data on the Jurassic-Cretaceous boundary interval of Eastern Crimea (Feodosiya)

The first compiled composite section comprises continuous succession of upper Tithonian-lower Berriasian strata (Jacobi Zone) from different isolated outcrops of the Feodosiya area. Based on new magnetostratigraphic and sedimentological data, the paleomagnetic section is correlated with succession of M20r, M19n, M19r, M18b chrons and M18n.1r Subchron (“Brodno”). The thorough complex bio- and magnetostratigraphic correlation of the upper Tithonian-lower Berriasian interval (Jacobi Zone) carried out through the Western Tethys and Eastern Paratethys provided grounds for first defining age analogs of the Durangites Zone in the Crimean Mountains and specifying location of the boundary between the Jurassic and Cretaceous systems, as well as for determining late Tithonian age of strata in the Dvuyakornaya Bay section barren of fossils.     

Potential field imaging of Palaeozoic orogenic structure in northern and central Europe

The Trans-European Suture Zone (TESZ) is the most fundamental lithospheric boundary in Europe, separating the ancient crust of the Fennoscandian Shield–East European Craton from the younger crust of central Europe, and extending deep into the mantle. Geophysical potential field images provide an overview of the entire Palaeozoic orogenic system of northern and central Europe for the first time. The TESZ is largely concealed by sedimentary basins of Permian–Cenozoic age; geological observations are largely restricted to local basement highs and deep boreholes, and the coverage of deep seismic surveys is widely spaced, despite experiments recently acquired within the EUROPROBE programme. By contrast, the potential field data offer a relatively detailed coverage of standardised observations throughout the TESZ. While some features of the images may be sourced in the near surface, particularly in the gravity image, much of their content reflects the structure of the underlying Palaeozoic basement. At the scale presented, the images highlight the most fundamental features of the crustal structure of the TESZ. These include the strong contrast between the highly magnetic crust of the East European Craton and the less magnetic Palaeozoic-accreted terranes of central Europe; the lateral continuity of terranes and their internal structure, particularly where arc-magmatic complexes are involved; and the location and geometry of the terrane boundaries (oceanic sutures and strike-slip zones) that separate them.     

Problem of the Formation of Eolian Gold Placers on the East European Platform

The distribution of eolian gold in various Proterozoic–Cenozoic sediments on the East European Platform is considered. Eolian placers of the Timan Ridge are characterized by specific features: significant areal distribution and consistent strike of the thin (0–30 cm) productive bed. Prospecting criteria of eolian gold placer in the study territory can be the presence of gold flakes and other minerals with signs of eolian reworking, specific structure of productive bed, deflation structure of relief, and characteristic lithological composition of sediments. It is concluded that since gold flakes with eolian reworking make up high metal concentrations, such as placer deposits in the Timan Ridge, eolian placers of different age may be found on the East European Platform.     

Tectonic differentiation of Precambrian basement formations in East European Platform

Principal unconformities and terminal folding, on the time scale from Belomorian through Caledonian, are correlated tentatively for constituents of the East European Platform (Baltic Shield, Ukrainian Massif, Eastern Margin, and their subordinates), Canadian Shield and Greenland, parts of Great Britain, and northern margin of the African Platform. — IGR Staff.     

Upper carboniferous conodont zones of Russia and their global correlation

The last decade has been marked by significant progress in the study of the stratigraphic ranges of the conodonts characteristic of the Kasimovian and Gzhelian stages in shallow-water sediments of the type sections in the Moscow Basin and the deeper facies of the South Urals. This paper discusses the history of studies of the Upper Carboniferous conodont zonation in Russia and abroad, and proposes a refined zonal conodont scale for the Kasimovian and Gzhelian stages, which may be included, as a standard, into the general Carboniferous scale of Russia. In this scale, the Kasimovian and Gzhelian stages correspond respectively to six (subexcelsus, makhlinae, sagittalis, cancellosus, toretzianus, firmus) and five (simulator, vitali, virgilicus, bellus, wabaunsensis) zones. The proposed scale works for the entire East European Platform and the Urals from the Novaya Zemlya Archipelago in the north to the Mugodzhary Mountains in the south. These regions of Russia are occupied by Upper Carboniferous marine facies. At several levels (especially in the Gzhelian Stage), the scale reliably correlates with zones of the Missourian and Virgilian stages in North America and also Dalaun and Mapingian stages in China.