New stratigraphie and palaeogeographic data on Upper to deposits from the eastern periphery of the Russian Platform (Russia)

Valentina S. VISHNEVSKAYA Institute of the Lithosphère, Russian Academy of Science, ILSAN, 22 Staromonetny, Moscow, 109180 (Russia) [email protected]

Patrick DE WEVER Laboratoire de Géologie, Muséum national d'Histoire naturelle, 43 rue de Buffon, F-75231 Paris cedex 05 (France) [email protected]

Evgeniy Yu. BARABOSHKIN Moscow State University, Geological Faculty, Vorobjovy Gory, 119899 Moscow (Russia) [email protected]

Nikita A. BOGDANOV Institute of the Lithosphère, Russian Academy of Science, ILSAN, 22 Staromonetny, Moscow, 109180 (Russia) [email protected]

Nikita Yu. BRAGIN Geological Institute of Russian Academy of Science, Pyzhevsky per., 7, Moscow, 109017 (Russia) [email protected]

Lubov G. BRAGINA Geological Institute of Russian Academy of Science, Pyzhevsky per., 7, Moscow, 109017 (Russia) [email protected]

Alesia S. KOSTYUCHENKO Technical University, Leningradskoe shosse 112-1-1-211, Moscow, 125445 (Russia) [email protected]

Emmanuelle LAMBERT Laboratoire de Géologie, Muséum national d'Histoire naturelle, 43 rue de Buffon, 75231 Paris cedex 05 (France) [email protected]

• 1999 • 21 (3) 347 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et al.

Yuriy M. MALINOVSKY Institute of the Lithosphère, Russian Academy of Science, ILSAN, 22 Staromonetny, Moscow, 109180 (Russia) [email protected]

Kulyash M. SEDAEVA Moscow State University, Geological Faculty, Vorobjovy Gory, Moscow, 119899 (Russia) [email protected]

Galina A. ZUKOVA Simbirsk Geological Survey, 3a Dovatora, Ulianovsk, 432000 (Russia)

Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. ef a/. 1999. — New stratigraphic and palaeogeographic data on Upper Jurassic to Cretaceous deposits from the eastern peri­ phery of the Russian Platform (Russia), in Crasquin-Soleau S. & De Wever P. (eds), Peri- Tethys: stratigraphic correlations 3, Geodiversitas 21 (3) : 347-363.

ABSTRACT The Late Jurassic and Late Cretaceous were periods when, after prolonged continental erosion, stable marine sedimentation took effect on the Russian Platform. The sediments which accumulated have diverse lithological com­ positions and a mixture of transient and endemic faunas. Lithological diversi­ ty and a wide variety of facies has led to problems in stratigraphical correlation of Late Mesozoic sequences and discrepancies in palaeogeographi­ cal reconstructions. Different faunal groups belonging to a wide variety of palaeozoogeographic provinces exist within these deposits. Therefore, we use all available microfossils (radiolarians, foraminiferas, nannoplankton) and KEYWORDS macrofossil groups (ammonites, buchias, inoceramides) in order to establish Jurassic, the synchronicity of anoxic and other events, to propose biostratigraphic Cretaceous, zonations and model the palaeogeography for Late Jurassic: lower stratigraphy, ammonites, Kimmeridgian and middle Volgian as well as Cretaceous time. We suggest radiolarians, that the Peri-Tethys of Eastern Europe is a unique area in which to solve the foraminifera, problem of stratigraphic correlation as it incorporates both Boreal and nannofossils, palaeogeographical map. Transitional to Tethyan palaeoclimatic provinces.

RESUME Nouvelles données stratigraphiques et paléogéographiques sur les dépôts juras­ siques et crétacés de l'extrémité orientale de la Plate-forme russe (Russie). Le Jurassique supérieur et le Crétacé forment une période où, après une longue érosion continentale, une sédimentation marine stable s'installe sur la plate-forme russe. Les sédiments accumulés ont des lithologies variées et pré­ sentent un mélange de faunes endémiques ou transitionnelles. La diversité lithologique et la grande variété de faciès ont rendu complexes les corréla­ tions stratigraphiques pour ces séries du Mésozoïque tardif et ont même créé des désaccords dans les reconstitutions paléogéographiques. Différents groupes fauniques, appartenant à une grande variété de provinces paléobio-

348 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

géographiques existent dans ces dépôts. De ce fait, nous avons été conduits à utiliser tous les groupes disponibles de microfossiles (radiolaires, foramini­ fères, nannoplancton) et de macrofossiles (ammonites, buchias, inocéra- mides) afin d'établir le synchronisme des événements, anoxiques ou autres, MOTS CLÉS pour proposer des zonations biostratigraphiques et des modèles paléogéogra­ Jurassique, phiques pour le Jurassique supérieur : Kimméridgien inférieur et Volgien Crétacé, moyen ainsi que pour le Crétacé. Nous pensons que la partie péri-téthy- stratigraphie, ammonites, sienne de l'Europe orientale est un endroit unique pour résoudre les pro­ radiolaires, blèmes de corrélation stratigraphique puisqu'il incorpore des éléments fau- foraminifères, niques de provinces boréales et de la transition vers les provinces nannofossiles, carte paléogéographique. paléoclimatiques téthysiennes.

INTRODUCTION MAIN LITHOFACIES AND STRATIGRA­ PHY OF THE KIMMERIDGIAN Our research team has undertaken field work in Volga River Basin (August 1995, members of The lower Kimmeridgian is represented by orga­ field work team were as follow: E. Baraboshkin, nic shale (Fig. 5, borehole 18) with clay (Fig. 5, N. Bragin, E. Lambert, V. Vishnevskaya, boreholes 15-17, 19, 20, 22, 23, 25-27), glauco- G. Zukova; August 1997, V. Vishnevskaya, nitic sandstone, aleurolite (almost equivalent to G. Zukova) and in the Timan-Pechora Basin silt-stone in Russian literature) and clay (Fig. 5, (September 1995, A. Kostyuchenko, G. Sedaeva, boreholes 24, 28), and micrite in the outcrops of V. Vishnevskaya). All previously published and the Ukhta section. Rare phosphatic pebbles and unpublished data concerning of these regions pyritic concretions were also found. were revised and taken into account. The time interval investigated corresponds to the The aim of our field trips was to collect precise early Kimmeridgian in terms of standard ammo­ and well-located samples with fossil material in nite zonation for the Boreal Realm of the order to establish accurate biostratigraphical cor­ Russian Plate. Within the Barents-Pechora area, relations and to propose palaeogeographic the Amoeboceras ravni zone and in the Volga- reconstructions which could provide a basis for Kama-Oka Basin, the A, kitcbini zone are pre­ modelling of palaeogeographic maps. sent. Other characteristic ammonites are Rasenia During the field work, we investigated and sam­ trimera Oppel and R. stephanoides Oppel. pled the following areas in detail: (1) Kim- Kimmeridgian strata, which yielded radiolarians meridgian-Volgian portion of the standard (Kozlova 1994; Vishnevskaya 1997), are well Gorodische Section of Volga River Basin and represented in the Timan-Pechora Basin. The Ukhta outcrop as well as 21 outcrops and Pechora-Volga sedimentary basin was probably 52 boreholes of the Volga-Kama and Timan- produced by a Late Jurassic phase of rifting Pechora Basin (Figs 1-5); (2) middle Volgian- (Kostiuchenko 1993), and was filled with radio- Hauterivian sections near Gorodische and New larian-bearing clay and shale deposits in a sub- Berdianka villages (Figs 2, 3); (3) Aptian-Albian platform environment. sections from boreholes of the Penza region The Kimmeridgian clay of Pechora and Ukhta (10 km of Penza town, west of Volga River); regions is also rich in glauconite and montmo- (4) Barremian-Turonian section to the north of rillonite. Glauconite (15-30%), montmorillonite Ulianovsk city; (5) Cenomanian-Maastrichtian (10-30%), hydromica (10-30%) and chlorite (5- sections near Shilovka settlement (50 km south 10%) are the dominant components in of Uljanovsk city). Kimmeridgian bituminous clay whereas glauco-

GEODIVERSITAS • 1999 • 21 (3) 349 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et al.

FIG. 1. — The location of investigated boreholes and outcrops of Timan-Pechora Basin (the numbers correspond to their official record). nite (30-40%), kaolinite (25-30%), and mont- the total fauna. Practically all taxa present are morillonite (20-30%) predominate in the known in the Boreal province of the Russian organic-rich Volgian shale. Platform and Circum-Pacific Rim. The lower The Kimmeridgian clay (5-45 m) from the Kimmeridgian radiolarian assemblage of the Pechora and Ukhta regions has a conformable Parvicingula vera zone of the Barents-Pechora- stratigraphic contact with the underlying strata Ukhta region includes: Archaeocenosphaera (Fig. 5) and demonstrates a succession of trans- inequalis (Rust), Praeconocaryomma ex gr. sphae- gressive and regressive characters up to Volgian roconus (Rust), Pseudocrucella aff. prava Blome, strata. Crucella crassa (Kozlova), C. squama (Kozlova), Radiolarian taxa make up only a minor part of C. aff. mexicana Yang, Orbiculiforma cf. iniqua

350 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

UPPER ) /""fti 0 km 30 ,—-XDubki / J~\ ' ' HAUTERIVIAN Undory^——J Gorodisçhef J Craspedites Novaya I I nodiger B^dengayruLIANOVSK y

Craspedites subditus

[. t::

LEGEND

Breccia

I I Sands

Sandstones

Siltstones

Clays

Oil shales

Argillites

Marls, clayei marls

Limestones

Carbonate clays

| . . | Phosphorites

$ $ I Bioturbation

5 S I Shell detrite

33371 Erosional surfaces 10 cm /Wy Softgrounds

FIG. 2. — The location of investigated sections of Volga Basin and stratigraphie column of the Volgian stage of the Gorodische Section.

GEODIVERSITAS • 1999 • 21 (3) 351 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et al.

Blome, 0.? retusa (Kozlova), Pantanellium tierra-

e v blankaense Pessagno & McLead, Parvicingula Zones GORODISCHE v^ \v °V> inornata Blome, P. cf. blowi Pessagno, P. haeckeli (Pantanelli), P. burnensis Pessagno & Whalen, P. pizhmica Kozlova, P. pusilla Kozlova, P. papula- HAUTERIV . ta Kozlova, P. santabarbarensis Pessagno, 7?? enor- inversus 4-1 20 mis Yang, /?? blackhornensis Pessagno & Whalen, ET. , Excinguldi bifaria Kozlova. o o — — The lower Kimmeridgian Parvicingula vera zone o —I of the Barents-Timan-Pechora Basin (Vish­ syzranicus o 6- 0.5 nevskaya & De Wever 1996) is probably equiva­ nodiger CO 5 0.1- lent to the lower Kimmeridgian Crucella crassa 0.5 subditus < 8-7 0-0.2 assemblage of Kozlova (1994) and correlates with O i fulgens O io­ 0.5- the Buchia concentrica zone, A. ravni ammonite > li 0.8 zone and Epistomina unzhensis foraminiferal zone nikitini 12- 0.3-

RAS . 17 0.5 as well. This interval probably corresponds to the virgatus 20- 0.8-

Kimmeridge Clay Hydrocarbon Formation of UP.J U e • e • e • 22 1 the North Sea which contains abundant P. jonesi -=—-— (Dyer & Copestake 1989). *

2 58- 6-

A study of Parvicingula distribution shows a pre­ 23 9 deri IA N arajsken: dominance of this genus in the Kimmeridgian of c N CD - _i- 1 the Timan-Pechora and Barents regions. Species CL O £> ti* £> — > 61- 0.5- vlovi of this genus are represented by a wide range of ns Q. 59 2.5 morphotypes. The co-occurrence of Arcto-Boreal pseudo- foraminiferal assemblages together with Jurassic

scvthica IA N 1 73- 3.5- CD radiolarians and Buchias confirms the possibility sokolovi _i ----<£--- 62 6 o of using Parvicingula as palaeoclimatic indicator klimovi •

(Vishnevskaya 1996). For example, the main 2 Kimmeridgian representatives of the Moscow eudoxus 80- 12- region are Parvicingula vera Pessagno & Whalen, KIMM . 72 18 P. inornata Blome, P. elegans Pessagno & Whalen. 1 Parvicingulides prevail, comprising 50% of this cymodoce assemblage and in the middle Volgian of the KIMM . Moscow Basin, are represented by P. haeckeli (Pantanelli), P. hexagonata (Heitzer) (Bragin Sand -cj>- I Radiolaria 1997). Clay © I Nannoplankton In the Gorodische Section (Volga Basin) Parvicingula jonesi (Pessagno) is the dominant Limestone |

352 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

Samples Total amount of samples Species diversity 15 20 I Y 95/11 -7 Y 95/11-8 I Benthos Y 95/11 -9- Y 95/11-11 ~j Necton Y 95/11-20 I os I Oil shales Y 95/11-10-4

Y 95/11-10-2

Y 95/11-22 OS Y 95/11-24, 10- Y 95/11-25

OS Y 95/11 -2i

Y 95/11-31

OS Y 95/11-3

OS Y 95/11-41

Y 95/11-41 Y 95/11-43- Y 95/11-5! Y 95/11-61 Y 95/11-61-1 SIZE-FREQUENCY DISTRIBUTION SIZE-FREQUENCY DISTRIBUTION OFLoripes fischerianus OFLoripes fischerianus (sample Y 95/10-2) (sample Y 95/11-26) Length 5 -| Length 5-| mm mm

4 4

3 3 2H 2 - 1 1 - 0 4, Samples I Li Samples • 1111—11111 0 14

Length 3.0 Diameter s-i mm

2.5

2.0

1.5

1.0

0.5 .Samples Samples 0.0 SIZE-FREQUENCY DISTRIBUTION SIZE-FREQUENCY DISTRIBUTION OFScurria maeotis OF Dorsoplanites sp. (sample Y 95/11-38) (sample Y 95/11-26)

FIG. 4. — The distribution of sampling and percentages of macrofauna in the Gorodische Section.

GEODIVERSITAS • 1999 • 21 (3) 353 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et al.

The upper Kimmeridgian (Eudoxus-Autis- sed by clayey-carbonate succession with thin siodorensis ammonite zones) sequences of the phosphorite and marcasite horizons (Fig. 3). Gorodische Section are represented by clay marl Several erosional surfaces are recognised in the with abundant nannofossils. Tergestiella margereli, subzone. Other ammonites include Zaraiskites Watznaueria communis and W. britannica are the sp., Z. cf. tschernyschovi, Z. cf. michalskii, dominant species. The characteristic species are Dorsoplanites aff. panderi, D. sp., Pavlovia sp., Stephanolithion bigoti, Discorhabdus tubus, numerous rostrums of Lagonibelus (L.) parvula Podorhabdus cylindratus, P. decussatus, P. cuvillieri, together with a benthic faunal assemblage of the as well as the smallest individuals of Nannoconus bivalves Loripes fischerianus, Buchia russiensis, steinmanni (= N. colomi). This nannoplankton Oxytoma sp., Protocardia concinna, Gresslya assemblage is similar to the NW European alduini, gastropods Eucyclus sp., Apporhais sp., Vekshinella stradneri assemblage of Bernard & Hay brachiopods Eingula sp., Rusiella sp., (1974). A more precise Kimmeridgian radiolarian Rhynchonella loxie; scaphopods Laevidentalium, zonation may be developed in the near future. as well as serpulids. These assemblages permit us The North Caucasus Kimmeridgian- to characterise sedimentary conditions as weakly assemblages include only rare P. dhimenaensis anoxic shallow water. (Baumgartner) and Berriassian assemblages in­ A somewhat richer fossil complex is present in clude P. boesii (Parona) (Vishnevskaya et al. 1990). the zarajskensis subzone (layers 58-23). The rocks The content of parvicingulides is less than 5% of of this subzone have rhythmical structure. the total assemblage in the Tethyan Realm. Rhythms usually begin with horizons of rework­ ed and dissolved fauna. They are overlain by car­ bonate clays topped with oil shale. The quantity VOLGIAN BIOSTRATIGRAPHY OF THE of organic matter increases from 1-1.5% up to PECHORA BASIN AND GORODISCHE almost 22% at the background of decrease of STANDARD SECTION carbonate matter (Fig. 3). Rhythmic changes in the benthic assemblage occur from a prevalence Volgian strata have a transgressive character in of benthos to an upsection increase of nekton the Pechora region (Fig. 5). Among radiolarians (Fig. 4). In the oil shales young populations of which occur within the middle Volgian lost Loripes fischerianus and Scurria maeotis usual­ Dorsoplanites panderi ammonite zone, ly prevail, together with nepionic ammonites. Parvicingula papulata Kozlova, P. conica This demonstrates a strong anoxic impulse (Khabakov), P. cristata Kozlova, P. rugosa during the oil shale formation. The following Kozlova, P. simplicim Kozlova are the dominant faunal assemblage was determined from that species. Parvicingulides again comprise up to interval: ammonites Zaraiskites cf. scythicus, 90% of faunas in the Barents-Pechora region. Z. pilicensis, Z. quenstedtii, Z. stchukinensis, Ammonites, buchias and foraminifera are also Dorsoplanites panderi; belemnites Lagonibelus (L.) abundant in these strata. magnifica, L. (Holcobeloides) volgensis, L. (L.) c£ rosanovi; bivalves Astarte sp., Gresslya alduini, The Gorodische Standard Section is the section Buchia mosquensis, B. russiensis, Oxytoma sp., which has been most completely processed for Loripes fischerianus, Nucula sp., Panopea sp., macro- and microfauna (Figs 2-4). Limatula consobrina, Liostrea plastica; gastropods Studies of the macrofaunal assemblage from the Scurria maeotis, Eucyclus sp.; scaphopods Gorodische Section show (cf. Mitta 1993), that Laevidentalium sp.; brachiopods Lingula sp., strata in the section can be confidently assigned Rhynchonella rouillieri and other fauna. to two ammonite subzones of the (middle The radiolarians Orbiculiforma ex gr. mclaughli- Volgian) Dorsoplanites panderi zone: The ni Pessagno, Stichocapsa? devorata (Rust), Pavlovia pavlovi bottom subzone and Zaraiskites Phormocampe favosa Khudyaev, Parvicingula zarajskensis top subzone, which were established hexagonata (Heitzer), P. cristata Kozlova, P. conica by Gerasimov & Michailov (1966). (Khabakov), P. aff. alata Kozlova, P. multipora The pavlovi subzone (layers 61-59) is characteri­

354 GEODIVERSITAS • 1999 • 21 (3) 17 24 25 28 27 19 20 21 15 18 16 23 26 22

|g Q | Ammonites |g^?[ Belemnites \S>^\ Buchia |^ ^| Anceline

|-y->[ Radiolarians | Flora \"Z^,\ Bioturbations

FIG. 5. — The distribution of Jurassic facies within the sections of the north-eastern part of the Russian Platform. For the location of boreholes see in Fig. 1. For legend of columns 1 14 see Vishnevskaya (1998), 29-52 see Vishnevskaya & Sedaeva (1999). P, ; T, ; J, Jurassic; K, Cretaceous; Q, Tertiary; a, Aptian; al, Albian; h-b, Hauterlvian Barremian; bs-v, Berriassian-Valanginian; nc, Neocomian; v, Volgian; ox-km, Oxfordlan-Kimmerldgian; cl, Callovian. Vishnevskaya V. S-, De Wever P., Baraboshkin E. Yu. et al.

(Khudyaev), P. aff. haeckeli (Pantanelli), P. aff. based on existing literature (Mesezhnikov 1984), spinosa (Grill & Kozur), Plathycryphalus? pumilus these strata can be correlated with the upper Rust, Lithocampe cf. terniseriata Rust were reco­ Volgian Craspedites nodiger zone and lower vered from within the Dorsoplanites panderi Valanginian Temnoptychites syzranicus zone. The ammonite zone in the Z. zarajskensis subzone - uppermost part of Volgian stage is characterised the uppermost part of nannofossil Watznaueria by appearance, within the radiolarian microfauna, communis zone of the Gorodische Section, where of the Mediterranean species P. boesii (Parana). dominant species of coccoliths are W. martelae, The appearance of this Mediterranean species W strigosa, W. tubulata, W. ovata. taxon notwithstanding, radiolarian assemblages Higher in the section (layers 22-20) thin mem­ are dominantly Boreal in character and the types bers of quartz-glauconitic sands and sandstones of radiolarian assemblages present have not been build up the succession. They contain horizons described previously. The proposed middle with reworked phosphorites. Faunas are located Volgian Parvicingula haeckeli zone is closely cor­ predominantly in rewashed pebbles. In layer 20, related to the Parvicingula papulata zone of the remains of strongly reworked zonal index Pechora Region (Kozlova 1994). It correlates gerassimovi were found together with with the ammonite Dorsoplanites panderi zone Loripes sp. and dissolved rostrums of Lagonibelus which can, in turn, be correlated with the (H.) volgensis. There are many radiolarians Evolutinella emeljanzevi- Trachammina septentrio- reworked from the Z. zarajskensis subzone within nalis or Saracenaria pravoslavlevi foraminiferal the phosphorite pebbles. zone (Kozlova 1994) in the Pechora Basin, Lenticulina biexcavata zone (Ljurov 1995) in the Ammonites from the succeeding Virgatites virga- Sysola hydrocarbon Basin, and Parhabdolithus tus next zone were not discovered. However, on embergeri nannoplankton zone in Middle Volga the basis of stratigraphic position in a detailed hydrocarbon Basin. We can trace last zone section, this zone most likely occurs between through both Southern England and North layers 18 and 20. France (Vishnevskaya & De Wever 1996). Due The uppermost part of section is comprises to the presence of index species, it is possible to dense thin members of carbonate sandstones correlate this interval with buchias Buchia mos- with huge ammonites Epivirgatites bipliciformis quensis-B. russiensis zone of the Russian Platform and E. nikitini (layers 17-12) from the middle (.Sey & Kalacheva 1993). Volgian E. nikitini zone. Sandstones of the upper Volgian Kachpurites ful- The proposed upper Volgian Parvicingula blowi gens zone lie above an erosional surface. They zone probably corresponds to the Pseudo- contain Craspedites nekrassovi, C. sp. and Kach­ crolanium planocephala assemblage of the purites fulgens associated with Buchia piochii, Pechora and North Siberia regions which was B. sp., belemnites Acroteuthis (A.) russiensis and established by Kozlova (1994) and can be corre­ A. (A.) mosquensis, which were found in layers 11 lated with Buchia piochii-B. terebratuloides zone and 10. of the Russian Platform (Sey & Kalacheva 1993). Overlapping layers 7, 8 also lie above erosional surfaces erosion and are characterised by rework­ ed Craspedites cf. okensis, which is the diagnostic JURASSIC PALAEOGEOGRAPHY form of the upper Volgian Craspedites subditus zone. The belemnites Acroteuthis (A.) mosquensis The Jurassic stratigraphic sequences in the and bivalve Buchia piochii and B. tenuicollis occur Timan-Pechora Basin (Fig. 5) clearly show a together with these ammonites. Radiolarian spe­ transgressive depositional system starting with cies P. cristata Kozlova, P. alata Kozlova, P. blowi Early-Middle Jurassic sands and deepening (Pessagno) and Stichocapsa devorata (Rust) are upward to the accumulation of the higher grade common within these strata in which the parvi- source rocks in the Volgian time. The mass cingulid content is 50-60%. extinction, observed here and especially in the No ammonite fauna was found in layers 6-5 , but Gorodische Section of the Volga-Urals Basin

356 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

FIG. 6. — Schematic palaeofacies location map of the Kimmeridgian time (adopted after Sedaeva & Vishnevskaya 1995). 1, coastal marine sandstone and slltstone; 2, marine clay; 3, anoxic organic shale; 4, lignite coal and organic detritus; 5, phosphate; 6, sup­ posed land; 7, location of sections from Fig. 5 (number in circle); 8, location of the Gorodische outcrops (letter in circle).

GEODIVERSITAS • 1999 • 21 (3) 357 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et ai.

(only about 40 species of ammonites, 20 species assemblages and some morphological peculiari­ of aucellids, 22 species of benthic foraminiferas ties of shells allow us to establish biostratigraphic and 20 species of planktonic foraminiferas, correlations and to reconstruct the possible 10 species of belemnites, 5-40 calcareous nanno- bathymetric and topographic features of sedi­ fossil taxa, 20 species of radiolarians and several mentary basins. One would notice that Jurassic species of algae were recognised within Dorso- radiolarian fauna was firstly found from the planitespanderi zone), probably resulted from the Gorodische Standard Section of the Volga Basin. cumulative effects of a constant alternation of It represents new data on the palaeontological transgressive and regressive episodes. This type of characteristics of the Upper Jurassic Russian sedimentation and palaeoenvironments survived Regional Volgian Stage. The lower Kimmerid­ into late Volgian time, but a change of condi­ gian ammonite Amoeboceras kitchini (Salfeld) is tions had already appeared by the end of Volgian typical of the Arctic (Northern Siberia, Subpolar time. Urals) and Boreal-Atlantic Provinces (European The proposed schematic palaeogeographic maps Russia). Buchia is a characteristic element of of the Kimmeridgian and Volgian time (Figs 7, Arctic and Boreal realms. Foraminiferas are also 8) indicate the location of the eastern rim of typical of the Boreal-Atlantic Province. A typical shallow sea with excellent environments for oil feature of radiolarian assemblages (abundance and fuel-rich organic source rocks (Figs 5, 6). and high taxonomic diversity of the genus Similar to Recent seas and to an ancient sea, for Parvicingula) indicates Boreal affinity. The pre­ example, the Sea (Vishnevskaya 1993), sence of the genus Aspidoceras in the Volga-Oka the maximum concentrations of phytoplankton, Basin, well-known in the Western Europe and siliceous plankton and benthos, carbonaceous Mediterranean Region, is the only indicator of plankton, nekton and benthos were found in the possible Tethyan influence. water immediately bordering the continent. This Some peculiarities were common for sediments type of relative increase in the proportion of lipid of the Pechora and Volga basins: rich organic matter in the bottom sediments and 1. Sedimentary lithologies and their thicknesses its good preservation probably took place in res­ indicate uneven subsidence on the periphery of ponse to the preservative character of phospho­ Russian Platform. rus, the content of which is very high in these 2. Alternation of deep-water and shallow-water strata (Baudin et al. 1996). sediments and numerous gaps indicate eustatic It is well-known that in the Tethyan Realm the variations. genus Parvicingula is rare whereas the content of 3. Geochemical data exhibit enrichment in orga­ this genus in the Boreal (Khydjaev 1931; Sedaeva nic matter. & Vishnevskaya 1995) and Australian provinces New siliceous microfossil radiolarian assemblages (Baumgartner 1993) is much greater. From these have been obtained from the Volgian as dated by data, we can assume that cold water environ­ ammonites and calcareous nannofossils. ments dominated the north-eastern Russian The co-occurrence of radiolarians with calca­ Platform Jurassic oil-shale-bearing basin. The reous nannofossils represents the first well-dated preponderance of parvicingulides possibly indi­ radiolarian assemblage of this age at such a high cates upwelling conditions which have could latitude on the Russian Platform. existed offshore (Figs 6-8). The abundant As might be expected many new radiolarian spe­ remains of sponge spicules, which settled along cies of the Boreal Province are encountered. the shelf edge confirm this conclusion.

LOWER CRETACEOUS STRATIGRAPHY JURASSIC BIOSTRATIGRAPHY AND OF ULJANOVSK-PENZA REGION PALAEOGEOGRAPHY Berriasian strata are probably reworked in the Detailed analysis of taxonomic variety of faunal Gorodische Section, although they were marked

358 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

50° E

10 9 HF1 IT|ii ITT112 fi rl 13 f^ni4 I <& I is I o [is

FIG. 7. — A detail palaeogeographic map of the Volglan time. 1, marl; 2, sand; 3, clay; 4, limestone; 5, oil shale; 6, land; 7, sponge; 8, aucelllne; 9, ammonite; 10, foramlnifera; 11, radiolaria; 12, bivalve; 13, glauconlte; 14, phosphate; 15, buchia; 16, gypsum.

GEODIVERSITAS • 1999 • 21 (3) 359 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et al.

(?mapped) according to Mesezhnikov (1984). Between 123.45 and 123.50 m, the radiolarians From our point of view, the presence of Berria- Porodiscus inflatus Smirnova & Aliev, Obeliscoites sian deposits here is improbable because the sec­ turris (Squinabol) are present. tion is strongly condensed. Most probably, Ber- At a depth of 133.15 to 133.25 m the radiola­ riasian ammonites which are present in these rians Dictyomitra ferosia angusta Smirnova and strata were reworked into the base of Valanginian. Stichomitra communis Squinabol were recovered. The section is terminated by black clays Within the interval 129.75 to 129.90 m, Albian (layers 4-1) with siderite and limonite concre­ species Crolanium cuneatum (Smirnova & Aliev), tions, containing large weathered ammonites C. triquetrum Pessagno, Porodiscus inflatus Speetoniceras (S.) versicolor and S. (S.) subinver- Smirnova & Aliev were met. sum, which are ascribed to the Speetoniceras At a depth of 136 m, the only species recovered inversum zone of the top Hauterivian. was Orbiculiforma multangula Pessagno occurred. An anoxic event occurred within the lower From the above data we consider that the Aptian Deshayesites desbayesi zone. The remainder Aptian-Albian Crolanium cuneatum zone can be of the lower and middle Aptian is characterised recognised in the Uljanovsk-Penza Region. by anaerobic conditions. A late Albian radiola- rian assemblage was found amongst the Albian black clay of Uljanovsk Section. It is represented UPPER CRETACEOUS BIOSTRATIGRAPHY by Orbiculiforma multangula Pessagno, Theo- OF VOLGA BASIN campe cylindrica Smirnova & Aliev, Obeliscoites turris (Squinabol). Upper Cretaceous radiolarians were studied from The Barremian-AIbian intervals were also investi­ the Shilovka Section in the Uljanovsk Region gated in two (7, 10) boreholes in the Penza area. and from core sections of boreholes (28, 502) At a depth of 89 m in borehole 10, the radiola- from the Volgograd Region. Three radiolarian rians Orbiculiforma maxima Pessagno, Distylo- assemblages were determined: Archaeospongo- capsa micropora (Squinabol), similar to late prunum bipartitum-Alievium superbum Albian Tethyan forms (C Dogherty 1995); (Turonian-Coniacian), Pseudoaulophacus floresen- Dictyomitra communis (Squinabol) and Obesa- sis-Euchitonia santonica (late Coniacian- capsula sp. cf. O. zamoraensis Pessagno were reco­ Santonian or Santonian) and Amphipyndax vered. At a depth of 105.5 m in the same tylotus-Patellula planoconvexa (late Campanian). borehole, typical late Albian radiolarian species Age data were supported by foraminiferal and Porodiscus kavilkinensis Aliev, Archaeodictyomitra nannoplankton assemblages, which have affinity simplex Pessagno, Dictyomitra gracilis (Squi­ with European ones. These assemblages are simi­ nabol), Dictyomitra ferosia augusta Smirnova, lar to Western Siberian Boreal associations, but Theocampe cylindrica Smirnova & Aliev were include some Tethyan taxa. recognised. At a depth of 106.8 m within bore­ The early Santonian Euchitonia santonica- hole 10, the radiolarian fauna is characterised by Alievium praegallowayi zone was established by Spumellaria only. Vishnevskaya (1997). It is a characteristic Boreal zone and is widespread both in Siberian, Russian Within borehole 7, at a depth of 113.3 m, radio- platforms and in the Pre-Caucasus. Within the larians Orbiculiforma nevadaensis Pessagno, Shilovka Section, it corresponds to the foramini­ Obeliscoites perspicuus Squinabol, O. cf. vinassai feral Gavelinella infrasantonica zone or nanno­ (Squinabol), Xitus antelopensis Pessagno, plankton Marthasterites furcatus zone. The late X.1 asymbatos Foreman, which are characteristic Santonian-early Campanian foraminiferal species of the Albian to early Cenomanian, were Gavelinella stelligera zone can be correlated with found. At a depth of 120 m (borehole 7) radiola- the Orbiculiforma quadrata-Lith ostro bus rostovze- rians are represented by the species Orbiculi­ vi zone. The upper part of this zone may be cali­ forma nevadaensis Pessagno and typical late brated with the nannoplankton Arkhangelskiella Albian Theocampe cylindrica Smirnova & Aliev, specillata zone in the Shilovka and Tushna sec- T. simplex Smirnova & Aliev.

360 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

65° N

H 3

8 © 9 ? 10 \ -if- 11 12 If f I 13 I f 114

FIG. 8. — A detail palaeogeographlcal map of Kimmeridgian time. Legend: see on Fig. 7, only 1, gravellite.

GEODIVERSITAS • 1999 • 21 (3) 361 Vishnevskaya V. S., De Wever P., Baraboshkin E. Yu. et ai

tions. Campanian Prunobrachium articulatum REFERENCES zone (Lipman 1952) or Amphibrachium siberi- cum zone and Spongoprunum angustum zones Anion E. & De Wever P. 1994. — Upper Cretaceous biostratigraphy of the borders of the Ural belts: (Amon & De Wever 1994) have no analogues in Western Siberian and Eastern Volga-Ural Basins: the Tethyan Region. Nevertheless, the Tethyan 229-262, in Roure F. (ed.), Peri-Tethyan Platforms. species Afens liriodes Riedel & Sanfdippo was Technip ed., Paris. found in the interval of this zone within the Baudin F., Hantzpergue P., Mitta V., Olferiev A. & Shilovka Section. Zakharov V. 1996. — Biostratigraphic correlations and black shale deposits of the Upper Jurassic from the Russian Platform. Abstracts of Peri-Tethys Conference, Amsterdam: 7, 8. CONCLUSION Baumgartner P. O. 1993. — Lower Cretaceous radio­ larian biostratigraphy and biogeography of north­ western Australian (ODP sites 765 and 766 and The proposed biostratigraphic subdivisions based DSDP site 261), Argo Abyssal Plain and lower on new palaeontological data are clearly defi­ Exmouth Plateau. Proceedings of the ODP, Scientific nable. They have a proven wide geographic dis­ Results, Washington 123: 299-342. tribution and can be useful for correlation of Bernard T. & Hay W. 1974. — On Jurassic cocco- sedimentary sequences as well as biotic and abio­ liths; tentative zonation of the Jurassic of Southern tic events. England and North France. Eclogae geologicea helve- ticae, Basel 67 (3): 563-585. The direct correlation of Peri-Tethyan radiolarian Bragin N. Y. 1997. — Radiolaria from the phospho­ zonations with oceanic ones and those of the rites basal horizons of the Volgian Stage in the Tethyan region is very difficult owing to provin­ Moscow region. Revue de Micropaleontologie, Paris ciality of species. Only one Jurassic zone, the 40 (4) : 285-296. upper Volgian-lower Berriasian Parvicingula Dyer R. & Copestake P. 1989. — A review of latest Jurassic to earliest Cretaceous Radiolaria and their blowi zone, can probably be compared with biostratigraphic potential to petroleum exploration zonations of Baumgartner (1993) for the Argo in the North Sea. Northwest European Micro- Basin. The upper Berriasian-lower Valanginian paleontology and Palynology, London: 214-235. Parvicingula khabakovi- Williriedellum salumicum Gerasimov P. A. & Mikhailov N. P. 1966. — Volgian zone (Vishnevskaya 1996), which is widespread Stage and the geostratigraphical scale for the Upper Series of the Jurassic System. Proceeding of Academy in the Russian and Siberian platforms within the of Sciences USSR, ser. geol., Moscow, No. 2: 118- ammonite Bojarkia mesezhnikovi zone, can be 138 [in Russian]. compare with some Tethyan ones owing to the Khudyaev J. 1931. — On the Radiolaria in phos­ presence of numerous Parvicingula boesii. phates in the region of the Syssola River. Biostratigraphic correlations of microfossils Transactions of the Geological and Prospecting Service ofU.S.S.R., Moscow, Fascicle 46: 1-48. (radiolarians, foraminiferas and nannoplankton) Kostiuchenko S. L. 1993. — The continental plate and macrofossils (ammonites, buchias) is propo­ tectonic model of the Timan-Pechora province sed in order to establish the synchronicity of based on integrated deep geophysical study. events and consequently of more general geologi­ Zonenshain memorial Conference on Plate Tectonics, cal processes. GEOMAR, Kiel: 85, 86. Kozlova G. E. 1994. — Mesozoic radiolarian assem­ blage of the Timan-Pechora oil field. Proceeding of Acknowledgements Sankt-Petersburg International Conference, St- We express our gratitude to Professor Petersburg: 60-75. Lipman R. X. 1952. — Materials on monographic A. Nikishin and anonymous reviewers for their study of Upper Cretaceous radiolarians from stimulating comments and criticism on the Russian platform. Paleontology and Stratigraphy, paper. We are grateful to J. Aitchison who helped Gosgeolisdat, Moscow: 24-51 [in Russian]. us to improve the English. Special thanks are due Ljurov S. B. 1994. — Division of Jurassic sequences to Peri-Tethys Programme (grants 9518 and 95- of the Middle Vichegda. Abstracts of International Symposium "Biostratigraphy of oil fields", December 96/18) and Russian Foundation for Basic 1994, St-Petersburg: 59, 60. Research for financial support (Grant RFFI 97- Mesezhnikov M. S. 1984. — Excursion 060. 05-65566) and to CNRS-ESA 7073. Boundary beds of Jurassic and Cretaceous in the

362 GEODIVERSITAS • 1999 • 21 (3) Upper Jurassic-Cretaceous of eastern Russian Platform

Middle Povolzhie and Riazanian region: 38-49, in Tethys. Abstracts of Moscow Peri-Tethys Workshop, The Central regions of European part of the Moscow: 30, 31. RSFSR. The summary guidebook of excursions 059, — 1998. — The domanikoid facies of the Russian 060, 066 XXVII International Geological Congress. platform and basin paleogeography, in Crasquin- Nauka, Moscow. Soleau S. & Barrier E. (eds), Peri-Tethys memoir 3: Mina V. V. 1993. — Ammonites and zonal stratigra­ Stratigraphy and evolution of Peri-Tethyan phy of the Middle Volgian of Central Russia. Platforms, Mémoires du Museum national d'Histoire Naukova Dumka, Kiev, 132 p. [in Russian]. naturelle, Paris, 177 : 45-69. O'Dogherty L. 1995. — Biochronology and paleon­ Vishnevskaya V. S., Agarkov Yu. V., Zakariadze G. S. tology of Mid-Cretaceous radiolarians from & Sedaeva K. M. 1990. — Late Jurassic- Northern Apennines (Italy) and Betic Cordillera Cretaceous radiolarians of the Great Caucasus as (Spain). Mémoires de Géologie, Lausanne, n° 21, key to determine age and paleoenvironment of the 415 p. Lesser Caucasus ophiolites. Reports of Russian Sedaeva G. M. & Vishnevskaya V. S. 1995. — Academy of Science, Moscow 310 (6): 1417-1421. Jurassic paleoenvironments of the North-Eastern Vishnevskaya V. S. & De Wever P. 1996. — About European platform. Zonenshain Conference on Plate possibility to correlate North Peri-Tethyan radiola- Tectonics, GEOMAR, Kiel: 205. rian events with others zonations. Abstracts of Sey I. I. & Kalacheva E. D. 1993. — Buchiids and Moscow Peri-Tethys Workshop, Moscow: 31, 32. zonal stratigraphy of the Upper Jurassic deposits of Vishnevskaya V. S. & Sedaeva K. M. 1999. — the northern Far East of Russia. Geologia and Reconstructions of sedimentary paleoenvironments Geofizica, Novosibirsk, 34 (8), 12 p. [in Russian]. of the north-eastern European platform and adjoi­ Vishnevskaya V. S. 1993. — Model of sedimentary ning areas for some intervals of Jurassic: 94-98, in basin for the Domanik-type deposits: new version. Geology and mineral resources of European North- Zonenshain memorial Conference on Plate Tectonics, Eastern Russia: New results and new perspectives, GEOMAR, Kiel: 151-152. Proceeding of XIII Geological Congress of Komi — 1996. — Parvicingula as indicator of Jurassic to Respublica. Volume 2. Geological Institute of Early Cretaceous paleogeographical and sedimento- Uralian Branch of Russian Academy of Sciences, logical paleoenvironments within North Peri- Siktivkar.

Submitted for publication on 22 April 1997; accepted on 30 June 1998.

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