An essay on regional geology and stratigraphy of the Upper Cretaceous deposits of southern Urals territories

Edward O. AMON Institute of Geology and Geochemistry, Urals-branch of Russian Academy of Sciences, 620219 Ekaterinburg, Pochtovyi per. 7 (Russia)

Joyce R. BLUEFORD Math/Science Nucleus, 4009 Pestana Place, Fremont, California 94538 (USA)

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

Victor I. ZHELEZKO Institute of Geology and Geochemistry, Urals-branch of Russian Academy of Sciences, 620219 Ekaterinburg, Pochtovyi per. 7 (Russia)

Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I. 1997. — An essay on regional geology and stratigraphy of the Upper Cretaceous deposits of southern Urals territories, in Crasquin-Soleau S. & De Wever P. (eds), Peri-Tethys: stratigraphie correlations, Geodiversitas 19 (2) : 293-317.

ABSTRACT The Turgay region is considered as the north-eastetn botdet of the Peri-Tethyan basins during the Cretaceous. This area contained elements of each atea's faunas; the relatively warm Peri-Tethys faunas with the cooler West Siberia faunas. Cretaceous deposits are found throughout the southern Urals, especially in the western and southern Primugodzharie, Aktyubinskian Priuralie, and Pri-Irgizsky areas. Cretaceous deposits are coveted by Cenozoic rocks, shown from well cores of the south-eastern border of Mugodzhar mountains, Turgay and northern PriAralie. The Lower Cretaceous in the sou­ thern Utals was predominately continental. In the western Primugodzharie and Aktyubinskian Priuralie region, marine sediments of Neocomian, Aptian and Albian age were deposited. Red continental sedimentary rocks were depo­ sited during the Neocomian. Coal and bauxite were deposited during Aptian and Albian. The Lower Cretaceous boundary was marked by a marine regres­ KEYWORDS stratigraphy, sion, while the Aptian and late Albian-early Cenomanian are characterized by correlation, extensive continental rocks on the entite territory, with the exception of the Cretaceous, Tutgay region. A widespread marine transgression is evident during the South Ural, paleontology. Cenomanian.

1997 • 19(2) 293 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

This transgression influenced the sedimentation in the southern Urals, East European, Scythian, Turan and West Siberian platforms. Upper Cretaceous was dominated by shallow marine facies, coastal and shore deposits. Marine transgression continued until late Maastrichtian. The end of the Late Maastrichtian was characterized by the appearance of very shallow water and lagoonal regressive facies. The Cretaceous/Paleogene boundary was marked by a pause of sedimentation with erosional unconformities in the boundary bet­ ween the Maastrichtian and Danian. Foraminifera, radiolaria, belemnites, sela­ chians, mollusca, pollen, and spore reveal the timing of events and suggest the paleoenvironment of this region during the Upper Cretaceous.

RÉSUMÉ La région de Turgay représente la bordure nord-orientale de l'ensemble Péri-Téthysien au Crétacé. Cette région comprend des éléments des diverses provinces fauniques; des faunes Péri-Téthysiennes relativement chaudes et des faunes froides Sibériennes. Des dépôts Crétacés existent partout dans l'Oural méridional, et particulièrement dans les zones occidentales et méri­ dionales de Prémugodzharie, du PériOural Aktyubinskien, et les zones de Péri-Irgizsky. Des forages de la bordure sud-orientale des monts Mugodzhar, Turgay et de PériAralie septentrionale ont révélé que les sédiments Crétacés sont recouverts de roches Cénozoiques. Le Crétacé inférieur de l'Oural sep­ tentrional est essentiellement continental. Dans le Primugodzharie occidental et la région du PériOural d'Aktyubinsk, des sédiments marins du Néocomien, de l'Aptien et de l'Albien existent. Des roches sédimentaires continentales rouges se sont déposées au cours du Néocomien, puis du char­ bon et de la bauxite à l'Aptien et à l'Albien. La limite inférieure du Crétacé est marquée par une régression marine alors que l'Aptien et l'Albien supé- rieur-Cénomanien inférieur est caractérisé par une grande extension des dépôts continentaux, sur l'ensemble du territoire, sauf dans la région de Turgay. Une large transgression marine se manifeste au Cénomanien. Cette transgression a influencé la sédimentation dans l'Oural méridional, l'Europe orientale, et les plates-formes Scythienne, de Turan et de Sibérie occidentale. Le Crétacé supérieur fut dominé par des faciès de mer peu profonde, et des dépôts côtiers et de rivage. La transgression marine a continué jusqu'au Maastrichtien supérieur qui s'est terminé par des faciès très peu profonds et régressifs lagunaires. La limite Crétacé/Paléogène fut marquée par une pause MOTS CLES de sédimentation et des discontinuités érosives à la limite Maastrichtien- stratigraphie, corrélation, Danien. Les foraminifères, radiolaires, bélemnites, sélachians, mollusques, Crétacé, pollens, et spores indiquent la chronologie des événements et révèlent les Oural méridional, types de paléoenvironment de cette région au cours du Crétacé. paléontologie.

INTRODUCTION evolve. During the Late Jurassic-Lower Paleogene, the Uralian epihercynian platform was generally Tectonic activity in the Uralian mobile belt cea­ uplifted. Mountain building coupled with ero­ sed at the beginning of the Mesozoic, completing sion were the predominate mechanisms during the suturing of the Russian platform and West this time. Thin beds of continental sediments Siberian plate. A new tectonic regime began to were accumulating in the surrounding basins.

294 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

During the early part of the Cretaceous, the northern portion of the Urals downwarped at a faster rate. A transgressive cycle flooded this region with northern boreal waters. This epicon­ tinental sea was a mixture of waters from the Polar, North Atlantic and North Pacific paleoba- sins. The southern portion of the basin was not invaded, as there is only evidence of continental sedimentation in local depressions. During the later part of the Cretaceous, the sou­ thern portion of West Siberia was tectonically downwarped allowing the transgressions to fully invade the Russian Platform, West Siberian Basin and Peri-Tethyan basins of the Turanian Plate. The Turgay trough allowed the north-western portion of central Asia and north-western Kazakhstan to experience marine conditions (Papulov 1974). This connection influenced the microbiota of West Siberian during the Late Cretaceous. Elements of the Tethyan fauna are found in semi-isolated marine basins. Components of foraminifera, radiolarian and mollusca of the West Siberian region can be correlated to the fauna of the Peri-Tethyan region. The Turgay Trough records this mixed fauna. The Turgay Trough is situated between the east­ ern slope of southern part of the Ural Mountains and the Kazakh Shield. The northern Turgay 0 35 70 105km area has well preserved Upper Cretaceous assem­ I I I I blages and is a reference section for foraminifera Fig. 1. — Location map. 1a, Or'-llek Hills area; 1b, Mugodzhar and radiolaria for Cenomanian, Conacian, Mountains; 1c, eastern Mugodzhar Mountains; 2a, Santonian, Campanian, and Maastfichtian. Aktyublnsklan Priuralle; 2b, western Primugodzharie; 2c, south­ Upwarping in the north near Kustanay City, ern Prlmugodzharie; 3a, north-eastern Usturt; 3b, northern PriAralle; 4a, western side of Turgay Trough; 4b, south-western Kazakhstan, was the southern limit between the Turgay; 4c, Turgay Trough; 4d, eastern side of Turgay Trough. West Siberian basin. South of this area marked the area of the Peri-Tethyan basins, where arctic- boreal waters of West Siberia mixed with the STUDY AREA warm waters of the Peri-Tethys. This basin has faunal representatives of the warm waters of Peri- This area encompasses a vast region (Fig. 1), with Tethyan basins with the arctic-boreal faunas of few outcrops. The termination of the Urals in West Siberian basins. These assemblages are key the south is bordered by the Or'-llek Hills and to understand the interaction of the West Mugodzhar Mountains. The Or'-llek Hills (alti­ Siberian, European, and Peri-Tethyan basins. tude 30-509 m) represents the divide between Understanding the biostratigraphy in the the Or' and Ilek Rivers basins. The Or'-llek Hills Cretaceous of the southern Urals will help to are approximately 100 km wide, ranging from correlate timing of events of the Peri-Tethys and Orsk City on the east to Aktyubinsk City on the West Siberia. west; and 200 km long, extending from the Ural River Valley on the north, to Kandagach in the

GEODI VERSIT AS • 1997 • 19(2) 295 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

south. The Mugodzhar Mountains are low moun­ tains south of the Or' River. The Mugodzhar Mountains consist in several ranges and groups of low mountains and hills. The highest peaks are approximately 650 metets. The Shoshkakolian Range (altitude 274-408 m) is the most southern extension of the Mugodzharian Range. The Poduralian area (Embian Plateau) is south­ west of the Or'-Ilek Hills, Mugodzhar Mountains and Shoshkakolian Range. The Embian Plateau is an etosional surface draining toward the PriCaspian lowland. The East Mugodzharian plateau is north-east of the Mugodzhar mountains and south of the Or' River. The East Mugodzharian plateau drains toward the Turgay plateau. The south-western portion is formed by the north-eastern frame of the Ustyurt Plateau (100-200 m) and the Shagray Plateau (100-150 m) and the Shoshkakolian Range in the south. The PriAralian Plain (150 m) is the territory north of Aral Lake. It contains the sandy Bolshie, Malye Barsuki, Barshakum and PriAralian Karakum Deserts. The eastern portion of Turgay Trough is the Turgay Plateau. It is spread between the massifs of the southern Ural mountains, east of the Mugodzhar Mountains and west of the low lying Kazakh Melkosopoch- nik Hills, Central Kazakh. The length is around 800 km (north-south), and width (east-west) is 300-450 km. The south-western part of Turgay Plateau, adjoin­ ing to the East Mugodzhar Plateau, is called the Pri-Irgiz Plain (150 m). The western part of the Turgay plain is the eastern border of Zauralian Plateau (altitude 250-350 m). The Turgay Plain in the north is called the Kustanay Plain (altitude 170-220 m); the central part is called the Aday-Ul'kayak plateau (altitude 220-300 m); the east is called the East Turgay Plateau (200-400 m) and the south is called the South Turgay Plain (altitude 150-180 m) (Miletsky, 1981; Ozhiganov 1964; Zakhatov & Udri 1971; Vereschagin et al. 1975; GerasimoveW. 1968; Yanshin 1953).

FIG. 2. — Scheme of structural-facies subdivision of the Urals during the Cretaceous. 1, Preduralie: 1a, Polar, Pripolar and northern Preduralie; 1b, middle and southern. 2, Zauralie: 2a, STRUCTURAL OVERVIEW OF AREA Pripolar and north-western Zauralie; 2b, Pripolar and north; 2c, middle and south-west; 2d, middle and south. 3, Predmugodzharie: 3a, Orsky area; 3b, Khobdinsky, lleksky, and The Urals are divided into areas that reflect dif- Zhurunsky area; 3c, north-west Turgay; 3d, north-east Turgay.

296 GEODIVERSITAS • 1997 • 19 (2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

ferences in structure and depositional environ­ The PriAralie Zone is located in the southern ments. The Russians refer to these as structural- adjoining plains (Fig. 1: 3a, b) The western por­ facies divisions. Figure 2 shows the genetal tion is referred to the north-eastern Ustyurt scheme of the structural-facies divisions of the region. It is formed by horizontally bedded Urals during the Cretaceous. This paper empha­ Neogene, Oligocene, Eocene, and Cretaceous sizes the Upper Cretaceous events that occurred deposits. This area is equivalent to the eastern in the southern termination of the Urals and part of the PriUstyurt area. The northern adjacent territories (Fig. 2: 3a-d)) PriAralie adjoins the North Aral Lake and is cha­ The southern Urals is subdivided into four main racterized by a Paleozoic geosyncline basement structural-facial zones (Fig. 1): (1) southern ter­ and thick Mesozoic-Cenozoic sedimentary cover. mination of the Utal Zone; (2) western adjoining The Turgay zone (Fig. 1: 4a-c) includes the plains or Primugodzharie and north-eastern Tutgay Plateau from the West Siberian plain in Pricaspian Zones; (3) southern adjoining plains the north to the PriAralian Karakum Desert in or PriAralie and north-eastern Ustyurt Zones; the south. There are several fold systems identi­ and (4) eastern adjoining plains or Turgay Zone. fied in this area, including the Kustanayan syn­ The Or'-Ilek Hills area corresponds to the clinorium, Ubaganian anticlinorium, Aksuat- Central Uralian anticlinorium and includes the skian synclinorium, and Esilskian synclinorium. area west of the Kosisteksky region (the southern In the eastern slope of the Urals, the Zauralian continuation of the Sakmarian Zone of southern anticlinotium is the western border of the Turgay Urals), and the area east of the Kempitsaysky trough. The south-western Turgay region is region (continuation of South Uralian Zone). situated between the Mugodzhar mountains and The Mugodzhar Mountain area (Fig. 1: la-c) the northern PriAralie. This area has a deeply fol­ includes the southern terminations of three ded basement with a well developed sediment widespread Uralian regional sttuctutal units: cover. In the southern portion is the boundary Tagil-Magnitogorskian synclinorium, East between the Central Kazakhstan fold system, Uralian anticlinotium, and portions of the PteCambrian and Early Paleozoic rocks outcrop Zauralian anticlinorium. in the Ulytauskian anticlinorium and form the The Primugdozharie Zone (Fig. 1: 2a) includes eastern frame of Turgay trough. This region is the area west of the Mugodzhar Mountains and is referred to as the eastern border of Turgay trough referred to as the Aktyubinskian Priuralie area. or eastern Turgay. These boundaries are well This corresponds to Aktyubinskian pericline documented in the literature (Miletsky 1981; trough of the Ural fold system, which is partly Ozhiganov 1964; Zakharov & Udris 1971; covered by Mesozoic-Cenozoic blanket deposits. Yanshin 1971; Vereschagin et al. 1975; Moskvin The western Primugodzharie (Fig. 1: 2b) is a 1986, 1987; Naidin et al. 1986; Papulov 1974). broad belt west of the Mugodzhar Mountains. This area corresponds to the Kempirsayskian Zone of Central-Uralian anticlinorium and to the STRATIGRAPHY OF CRETACEOUS eastern botdet of Pri-Caspian depression of East DEPOSITS European platform. The western portion of the western Primugodzharie and southern Primugod­ CENOMANIAN (Figs 3-5) zharie areas are similar to the east-north-eastern During the Cenomanian, the southern Urals parts of the PriCaspian lowland area. In the south­ range from continental to marine. Continental west area of the Mugodzhar Mountains, the and semi-marine (lagoonal lacustrine) rocks of region referred to the southern Primugodzharie is upper Albian to lower Cenomanian (Altykuduk- located (Fig. 1: 2c). The Shoshkakolian Range is skaya Formation). Coastal marine rocks are cha­ located in this region and is considered as a conti­ racteristic of the Nogaytinskaya Formation nuation of the Mugodzhar Mountains, which is (Primugodzharie and PtiAralie) in rhe equivalent to the eastern part of south Emba area Primugodzharie and PriAralie regions. Semi- (Zakharov & Udris 1971; Sobetski 1982). marine and continental rocks of Cenomanian-

GEODIVERSITAS • 1997 • 19(2) 297 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

Turonian age (Shetiregizskaya and Novoko- Albian Karashataukskaya and Kysylshenskaya zyrevskaya Formation) are located in Turgay. Formation. In the western area the Lower-middle Cenomanian coastal marine depo­ Altykudukskaya Formation has surface outcrops. sits are found in the western Primugod- Throughout the rest of the region, the depth has zharie and Aktyubinskian Priuralie. Upper been determined by boreholes (Zhelezko & Cenomanian deposits in the western areas are Segedin 1972; Miletsky 1981). absent. The Altykudukskaya Formation mainly consists The late Albian - early Cenomanian Altykuduk- of white to yellow, siltstones to conglomerates, skaya Formation occurs on marine deposits of unconsolidated clays to gravel, with sandy the Aptian-Albian Bogdanovskaya Formation in concretions and plant debris. Two sections can the Aktyubinskian Priuralie region. The be recognized. The lower unit contains light grey Altykudukskaya Formation in western to yellow-grey, poorly sorted, quartz rich sands in Primugodzharie and Or'-Ilek Hills is unconform- horizontal or slanting beds. Gravel and pebbles are ably laid on Paleozoic rocks. In the southern found in the sand layers with kaolinite. The total Primugodzharie, north-eastern Ustyurt and thickness of the lower unit ranges from 20-120 m. northern PriAralie, the Altykuduskaya Formation Spores and pollen (SPA IV. 1) from early lies on the continental deposits of the Aptian- Cenomanian age are found in the lower units.

FIG. 3. — Correlation of Upper Cretaceous deposits of eastern PriCaspian, Aktyubinskian Priuralie, and western Primugodzharie.

900 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

The upper portion of the Altykudukskaya Palaeoanacorax obliquus Zone (early-middle Formation is found in the western areas and has Cenomanian); mollusca of Oxytoma pectinata well preserved selachia (shark teeth) which are Zone (early Cenomanian); and foraminifers of from the Palaeoanacorax volgensis Zone of AJbian- the Gavelinella cenomanica Zone (early-middle early Cenomanian age (Zhelezko & Segedin Cenomanian) are found. The total thickness 1972). Flora from the Koldenen-Temirskian ranges from 20-40 m (Nevesskaya 1985; Azbel paleoflota (LFA 1) of late Albian-Cenomanian &Grigyalis 1991). age is found in sandy horizons (Shilin 1986). The western Primugodzharie, transgressive depo­ In the eastern PriCaspian region, transgressive sits of marine quartz sands, siltstones and clayey Cenomanian coastal and deeper marine deposits siltstones of the Nogaytinskaya Formation over­ are found on continental Albian rocks. The lies continental deposits of the Altykudukskaya Cenomanian rocks in this area consist of yellow- Formation. The total thickness of the grey, green-grey, yellow, quartz rich glauconite Nogaytinskaya Formation is 5-10 m. Typically sands, gtey sandy clays, and sandstones. clayey siltstones are in the upper portion, with Ammonites of the Kamaroites grossouvrei Zone beds of mollusca and selachians of the (early-middle Cenomanian); selachians of the Palaeoanacorax obliquus Zone towatd the middle

Southern Primugodzharie Or'-llek Hills North-eastern Ustyurt Turgay Northern PriAralie

marly, chalky, clayey, sandy Zhuravlevsakya Formation sandy, clayey, marly, siliceous marine coastal rocks marine coastal, marine rocks

20-170 m i 5-65 m clayey, marly, sandy marine o sandy, coastal rocks, marine rocks sandy, silty, « clayey clayey / 0> ^continental | 110 m siliceous marine 4; coastal- coastal, clayey, marly clayey, sandy, marine rocks marine coastal, marine coastal, marine rocks marine rocks 87 m 20 m

clayey, sandy marine coastal, marine rocks

c/ 15m

sandy, clayey continental, clayey, sandy, sandy, clayey, .marine rocks

coastal marine rocks silty continental silty I 30 m rocks marine rocks |— 'continentaI co l sandy, 70 m _ 80 m _ I rocks 30 m sandy, silty clayey continental, contin­ semi-marine Altykudukskaya Formation ental rocks sandy, clayey continental, coastal-marine, rocks

lagoonal rocks 25 m 0-100 m 20-160 m

FIG. 4. — Correlation of the Or'-llek Hills, southern Primugodzharie, and Turgay.

GEODIVERSITAS • 1997 • 19(2) 299 Anion E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

to lower portion of the section. Conglomerates lower coarse grained sandstone, a middle bauxite and sandstones are in the bottom of the section bearing layers, and an upper kaolinite clay with (Zhelezko & Segedin 1972). plant remains. The lower part usually contains spores/pollen association of early Cenomanian CENOMANIAN-TURONIAN (Figs 3-5) age, with the middle and upper layers containing The Cenomanian-Turonian rocks are widespread late Cenomanian-early Turonian age (Papulov et in the Turgay trough and represented by the al. 1990). Shetirgizskaya Formation (continental to semi- There are other Cenomanian-Turonian deposits marine) and Novokozyrevskaya Formation in the western side of the Turgay trough, deposi­ (continental). Surface outcrops are only found in ted in a lacusttine/continental environment. It erosional and karst deptessions. outcrops in karst depression and othet erosional Composition of the Shetirgirzkaya Formation regions. Near the Ayat River, an outcrop of varies with the area. In the northern part of the approximately 16 m is found. The base of the Turgay trough, the Shetirgirzkaya Formation is section has sandstones with Paleozoic weathering about 10 m thick, composed of green-green debris. Kaolinite clays with lignite overly grade monmorillonite-beidellite sandy silty clay to kao- into quartz rich sands toward the top of the sec­ linite clays with lignite, coal and pyrite. This sec­ tion. Santonian oolitic bearing sands are found tion lies unconformably on Carbonifereous lying conformably on the top of the section. This limestones, with Santonian marine deposits lying deposit contains spores/pollen of late Cenoma­ on top of the section (Papulov et al. 1990). nian-early Turonian age, with a flora assemblage In the southern part on the Kazakh Republic, the of Turonian age called the Ayatskian- deposits are thicker (up to 60 m) and range from Kazakhstanian flora (Shilin 1986). coarse grained sandstones to silty claystones, with In the north-eastern corner of the Turgay region, some plant debris. The lower portion of the the Upper Cretaceous sedimentary sequence of Shetirgizkaya Formation contains spores/pollen Turgay, is replaced by West Siberian sequences. of early Cenomanian age, while the upper por­ The semi-marine deposits of Shetirgizskaya tion corresponds to late Cenomanian-early Formation is gradually replaced by the semi- Turanian. Flora of Cenomanian-Turonian age is marine West Siberian Uvatskaya Formation, also found of the Ayatskian regional flora (Shilin which contains the Trochammina wetteri- 1986). Marine deposits of the Santonian age lie Trochammina subbotinae Zone of late Cenoma­ on top, while Albian grey clays are at the base of nian. The radiolarian zonation also correlates a the section. late Cenomanian age (Cenodiscus cenomanicus- Stichocapsa ferosia uvatica Zone). The Novokozyrevskaya Formation lies on wea­ thered Paleozoic rocks throughout the region. Overlying disconformably varies from Santonian, TURONIAN (Figs 3-6) Campanian, Maastrichtian or Paleogene, depen­ Continental, marine, and coastal-marine deposits ding on the location. A 43 m section is found in of Turonian age are widespread in southern the Novokozyrevsky quarry, near the Tobol River Primugodzharie, northern PriAralie, and Turgay near the town of Oktyabrsky. The bottom of the Trough in subsection. The thickness of Turonian section contains kaolinite-hydromica clays with deposits ranges from several meters in the north clasts of Paleozoic rocks. A 15 m layer of bauxite, to 80 m in the south in the southern Primugod­ which is commercially mined, is present up in zharie, and increases to 300 m in the PriAralie the section. The top of the section is approxima­ region. tely 15 m of kaolinite-gibbsite dark clay with In the Aktyubinskian Priuralie, deposits of lignite and coaly plant deposit, with the upper­ Turonian age are found on Cenomanian sand­ most containing bauxite with plant remains. stones along the Ilek River. Marine clay rich The Novokozyrevskaya Formation throughout quartz sandstones and clays (up to 12 m) are this region ranges in thickness from 0-100 m. It found with Inoceramus and ammonites of the late can be characterized by three parts including a Turonian Inoceramus labiatus Zone and foramini-

300 GEODIVERSITAS • 1997 • 19(2) Foram inifera Radiolaria Belemnites Selachians Mollusca

Hanzawaia ekblomi Spiroplectammina Neobelemnella Oxyotoma danica kasanzevi kazimiroviensis Brotzenella praeacuta Squalicorax Belemnella sum. sumensis pristodontus / Orbiculitorma Gaudryina rugosa spinulosa Belemnelia lanceoiata Oxyotoma uralica renillaeformis Belemnella licharevi

Bolivina kalinini - Brotzenella taylorensis Amphipyndax Belemnitella ex gr. langei Squalicorax ex gr. Inoceramus balticus Belemnitella mucronata Spiroplectammina optata stocki mucronata pristodontus Belemnellocamax mammilatus / Squalicorax plicatus Belemnitella mucronata alpha Prunobrachium Spiroplectammina senonana pocurica crassum Actinocamax laevigatas / Belemnitella praecursor Squalicorax lindstromi mucronatitormis

Belemnitella praecursor Oxyotoma praecursor Squalicorax kaupi Ammobaculites dignus tenuicostata / Pseudoclavulina hastata admota Squalicorax papulovi Goniocamax lundgreni Inoceramus uillcus Squalicorax santonicus cardissoides

Goniocamax lundgreni Haplophragmium chapmani lundgreni Squalicorax falcatus Inoceramus Ammoscalaria antis / schloenbachi Reussella kelleri

Goniocamax intermedius Squalicorax sagiscus Inoceramus Palaeonacorax / intermediumus labiatus

Trochammina wetteri 'rochammina subbotinae Stichocaspa Ligulogavelinella globosa Rotalipora ferosia utavica cushmani

Gavelinella Thalmanninnella Palaeonacorax Kamaroites baltica deeckei / Gavelinella obliquus grossouvrei cenomanica c? Hoeglundina Thalmanninnella Palaeonacorax postdorsoplana Oxytoma pectinata appenninica volgensis

FIG. 5. — Correlation of foraminlferans, radiolarlans, belemnites, selachians, and mollusca In the southern Urals region (adapted from Naidln era/. 1984a, b; Naidln & Kopaevlch 1977; Azbel & Grigyalis 1991). Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

fers of the late Turonian Gavelinella moniliformis The Turonian deposits of the southern Zone. Santonian rocks are found conformably Primugodzharie outcrop near the flanks of the on top of this section. Shoshkakolian anticlinorium. In the northern In the Kazakh Republic, near Novofedorovsky, a portion of this area the deposits are continental, 13 m section lies on Cenomanian sandstones. but become more influenced by marine sedimen­ The section contains a phosphoritic horizon of tation in the south of the Shoshkakolian Range concretions in quartz-glauconite sandstone. Dark area. On the Ustyurt plateau and in the grey to green grey clayey marls are found in the north-western pan of the PriAralie (Kulandy rest of the section. The section is overlain by Peninsula of the Aral Lake), the Turonian depo­ Santonian phosphoritic layer. sits are matine. In the south-eastern Turgay area, In the Or'-Ilek Hills area, in the Kirgeldinsky the Turonian rocks range from continental (earl­ graben on the Ural River, the Turonian is repre­ iest sedimentation) to coastal-marine (latest). sented by micaceous quartz rich sandstones and Continental deposits of kaolinite clays, sand­ siltstones. Inoceramus lamarcki park can be found stones, and siltstones are called the Zhirkindek- in this region. skaya Formation in the southern Primugod-

Russian Platform Western Kazakhstan Crimea, Caucasus, Carpathians

Pseudotextularia varians Abathomphalus mayaroensis »? Hanzawaia ekblomi / Brotzenella praeculata Bolivinoides draco draco Brotzenella complanata Globotruncana stuarti / Brotzenella complanata Angulogavelinella gracilis Brotzenella tayiorensis -e. Globorotalites embdyensis Bolivina kalinini Globotruncanita morozovae V* Cibicidoides voltzianus Brotzenella monterelensls / Cibicidoides Cibicidoides / Cibicidoides termirensis termirensis aktulagayensis

Bolivinoides strigillatus »? Gavelinella stelligera Globotruncana fornicata / Osangularia whitei whitei / Stensioeina granulata perfecta <** Gavelinella infrasantonica Globotruncana concavata

Stensioeina exculpta granulata »? Gavelinella costulata Globotruncana primitiva / Stensioeina granulata granulata / Gavelinella kelleri Globotruncana angusticarinata

Gavelinella moniliformis »? Ga velinella praeinfrasantonica Globotruncana lapparenti Gavelinella ammonoides Gavelinella moniliformis / Gavelinella nana Globorotalites hangensis Helvetoglobotruncata helvetica 4 Hedbergella holtzi

FIG. 6. — Correlation of foraminifera zones from the Russian Platform, western Kazakhstan and Crimea, Caucasus, and Carpathians (western part of the west European Paleobiogeographic provinces).

302 GEODI VERS ITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

zharie, northern PriAralie, and south-western Stensioeina granulata granulata Zone. Turgay. In western Primugodzharie and Aktyubinskian Marine deposits of Turonian-Coniacian age com­ Priuralie, the upper Coniacian deposits are repre­ posed of greenish monmorillonite with admixtu­ sented by the lower portion of the Kubleyskie re of kaolinite, with interlayers of glauconite beds, which is found in the basal section of the quartz rich siltstones, clayey siltstones, and fine Koldenen-Temirskaya Formation. It is light grained sandstones are found in Northern green, fine grained sandstones and siltstones with PriAralie. The total thickness of these deposits a phosphoritic unit (Zhelezko & Segedin 1972; ate approximately 100 m. These deposits contain Zhelezko 1987, 1988). Upper Coniacian belem- macrofossils of the late Turonian Inoceramus nites of the Goniocamax lundgreni lundgreni labiatus Zone and Coniacian Inoceramus schloen- Zone and selachians of the Squalicorax falcatus bachi Zone (Yanshin 1953). Zone are found in this horizon. These are ttans- In the eastern PriCaspian region, late Turonian gressive deposits found on Cenomanian sand­ deposits are light grey - grey sandy limestones, stones of the Altykudukskaya Formation; on carbonate sands, with a phosphoritic horizon in marls of Turonian age; and/or on deposits of the the base. The total thickness ranges from Zhirkindekskaya Formation. In the Turgay 2-25 m. These marine deposits contain macro- Trough, Coniacian intervals are not found. fossils of the late Turonian Inoceramus labiatus Sedimentological evidence shows that they were Zone, Squalicorax sagisicus Zone and the forami- probably eroded. It has been suggested that por­ niferal Gavelinella moniliformis Zones. Conti­ tions of the Eginsayskaya Formation, in the nental deposits contain spore/pollen in the northern part of Turgay, is Coniacian. This cor­ SPA IV.3 Zone. relation is only possible because the Eginsayskaya The Ayatskaya Formation in Turgay, was former­ Formation in West Siberia contains Coniacian ly considered Turonian deposits, but is not consi­ foraminifers of the Haplophragmium chapmani- dered Turonian in this study. In the Ammoscalaria antis-Reusella kelleri Zone and north-eastern region of the Turgay region near Coniacian radiolarians of the Ommatodiscus the boundary of the West Siberian platform, the mobilis Zone (Amon 1988, 1990). Turgay faunas are replaced by West Siberian fau­ nas. The foraminifera and radiolaria indicate SANTONIAN-CAMPANIAN (Figs 3-6) Tutonian age in the West Siberian Uvatskaya and Marine deposits of Santonian-Campanian age Kuznetsovskaya Formations (Amon 1988, 1990). are found in the western Primugodzharie and Aktyubinskian Priuralie. Upper Coniacian-lower CONIACIAN (Figs 3-6) Campanian deposits of the Koldenen-Temitskaya Coniacian deposits ate absent from the majority Formation includes two lithologic units. The of the tegion, but are found in the extreme west, lower unit is sandy-phosphoritic Kubleskie Beds south, and east. These deposits may have been and is 9 m thick. The uppet unit is a phosphori­ eroded during a very dynamic transgression tic siltstone, 17 m thick, called the Zhurunskie during the Santonian-Campanian. Beds. Lower-upper Campanian Zharykskaya In the Western Primugodzharie region, marine Formation and upper Campanian Kursayskaya rocks of Coniacian age are present. They are Formation are also found in these regions. chalky marls, marls and clays with a thickness of Outcrops of the Koldenen-Temirskaya and approximately 5 m. In the south-western to Zharykskaya Formation on the Temir, Koldenen- southern Primugodzharie, 15 to 20 m of marine Temir, and Kubley Rivers have provided a conti­ blue-grey sandy limestones with phosphoritic nuous section. This sequence contains late concretions and sandy carbonate claystones are Coniacian, Santonian and early Campanian Coniacian. This deposit contains the molluscan deposits. Inoceramus schloenbachi Zone and the foraminife- Light green, fine grained sandstones and silt­ ral Gavelinella kelleri Zone (early Coniacian) and stones with a phosphoritic horizon make up the late Coniacian Gavelinella costulata and Coniacian interval. Lower Santonian intervals,

GEODIVERSITAS • 1997 • 19 (2) 303 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

ranging from siltstones to fine grained sand­ pristodontus Zone, foraminifers of the Bolivina stones, contain two phosphoritic horizons. Early kalinini Zone and Brotzenella taylorensis Zone are Santonian belemnites of the Goniocamax lund- found in this area (Zhelezko & Segedin 1972; greni uilicus 'Lone, and selachians of Squalicorax Zhelezko 1988; Naidin et al. 1991). santonicus Zone and Squalicorax paulovi Zone are In the eastern margin of the PriCaspian Zone, helpful to define this layer. Foraminifers of the Santonian marine deposits, mixed with Stensioeina exculpta exculpta Zone and Stensioeina Campanian deposits, ate widespread. The granulata perfecta Zone indicate an early Santo­ Santonian deposits can be divided into lower and nian age. The late Santonian interval contains upper units. The lower Santonian sediments are belemnites of the Belemnitella praecursor praecur- 10-50 m of light grey, green-grey, blue grey sor Zone, bivalves of the Oxytoma tenuicostata sandy limestones, with rare phosphoritic concre­ Zone, selachians of the Squalicorax kaupi Zone, tions. Interlayers of calcareous sands and chalk­ and foraminifers of the Gavelinella stelligera like, clayey limestones are also present. There are Zone. Early Campanian contains belemnites of belemnites of the Goniocamax lundgreni uilicus Actinocamaax laevigatus-Belemnitella praecursor Zone (early Santonian), selachians of Squali­ mucronatiformis Zone, selachians of Squalicorax corax santonicus Zone (early Santonian), sela­ lindstromi Zone, fotaminifers of Gavelinella cle- chians of Squalicorax papulovi Zone mentiana clementiana Zone and Bolivinoides (early-middle Santonian); foraminifers of decoratus decoratus Zone. Stensioeina exculpta exculpta Zone (early Zharykskaya Formation in western Primugod- Santonian or late Coniacian-Early Santonian). zharie and Aktyubinskaian Priuralie, was deposi­ The upper Santonian sediments range in thick­ ted transgressively over the Koldenen-Temirskaya ness from 5-35 m and are light grey, green-grey, Formation. Rhythmically alternating layers blue-grey sandy clays and limestones, with rare (5-7 m thick) of silty, marly, dark grey to green- phosphatic and pyritic conctetions. There are grey clays, and glauconite light grey, yellow grey belemnites of Belemnitella praecursor praecursor siltstones with phosphoritic concretions, reach a Zone (late Santonian); mollusca of the Oxytoma thickness of 40 m in the Zharyskaya Formation tenuicostata Zone (late Santonian); selachians of (Zhelezko & Segedin 1972; Zhekezko 1988; the Late Santonian Squalicorax kaupi Zone; fora­ Naidin et al. 1991). Rocks in the lower portion minifers of Gavelinella stelligera Zone (late contain early Campanian belemnites of the Santonian or late Santonian-eatly Campanian). Belemnellocamax mammilatus-Belemnitella The Campanian deposits of the Eastern mucronata alpha Zone; selachians of the PriCaspian Zone are divided into lower and Squalicorax plicatus Zone and foraminifers of the upper sedimentary units. Lower Campanian Cibicidoides temirensis Zone. The upper portion sediments (5-30 m) are light grey, chalk-like of the formation contains late Campanian limestones, marls, calcareous clays with belem­ belemnites of the Belemnitella mucronata mucro­ nites of Actinocamax laevigtus-Belemnitella prae­ nata Zone, foraminifers of Brotzenella montere- cursor mucronatiformis Zone (early Campanian), lensis Zone and Cibicidoides voltzianus Zone. Belemnellocamax mammilatus-Belemnitella The late Campanian Kursayskaya Formation in mucronata alpha Zone (early Campanian); sela­ the western Primugodzharie and Aktyubinskian chians of Squalicorax lindstromi Zone (early Priuralie transgressively lies on the Zharykskaya Campanian), Squalicorax plicatus Zone (early Formation. The Kursayskaya Formation is com­ Campanian); and foraminifers of Gavelinella cle­ posed of calcareous light-yellow-grey siltstones, mentiana clementiana Zone (early Campanian), silty marls with isolated phosphoritic concre­ Bolivinoides decoratus decoratus Zone (early tions, as well as phosphoritic horizon toward the Campanian), Cibicidoides temirensis Zone (early base of the formation, with a thickness of 15 m. Campanian). Upper Campanian sediments are Late Campanian belemnites of the Belemnitella light green to grey, sandy marls, clayey chalk and ex gr. langei Zone, mollusca of the Inoceramus range in thickness 5-30 m. There are belemnites balticus Zone, selachians of the Squalicorax ex gr. of Belemnitella mucronata mucronata Zone (late

304 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

Campanian), Belemnitella ex gr. langei Zone (late the Kuznetsovskaya Formation of West Siberia. Campanian), foraminifers of Brotzenella montere- Spores and pollen give this group an age of lensis Zone (late Campanian), Cibici-doides volt- Turonian. The sedimentary rocks include lami­ zianus Zone (late Campanian), Bolivina kalinini nated, yellow-grey, quartz rich medium grained Zone (late Campanian), and Brotzenella tayloren- sandstones and yellow-grey silty clays. This sis Zone (late Campanian) (Naidin et al. 1991) group is terminated by a stratigraphic unconfor­ Santonian-Campanian marine rocks in the nor­ mity. thern portion of PriAralie and southern Tutgay The Eginsayskaya Formation is composed of are transgressively laid on continental Tutonian- both Santonian and Campanian rocks. The Coniacian deposits (Papulov & Naidin 1979). Santonian Eginsayskaya Formation is confirmed The lower units have a thin layer (1-2 m) of by several fossil groups. A 5.3 m thick horizon of conglomerate which contains sands, phosphoritic dark-grey platy clays with interlayering of glau- conctetions, pebbles of argillites, mollusca, shark conite quartzeous siltstones and conctetions of teeth, silicified wood, cemented with calcateous siderite uses pollen and spotes. A 3.3 m horizon clay. Santonian deposits include marine sands of green-grey siltstones and sandstones has evi­ with gravel and phosphoritic concretions. dence from cephalopods (Baculites), bivalves Mollusca of the late Santonian age, Oxytoma (Trigonia), selachian, spores and pollen. Spores tenuicostata Zone; selachians of Squalicorax kaupi and pollen are used in a 3.1 m thick horizon of Zone. Campanian deposits are represented by the dark-grey, black solid silty clays. A 4.1 m thick calcareous clays and marls with belemnites of horizon of gteen-grey clayey quartz-glauconite Belemnitella mucronata Schloth., sJ.; foraminifers sandstones and siltstones, with interlayers of of Early Campanian Cibicidoides temirensis Zone sandy dark-grey clays, are in the Ammobaculites which resembles the Early Campanian Zones of dignus-Pseudoclavulina hasttata admota foramini- the Mangyshlak and PriCaspian depressions. fer Zone and are found along with selachian, In the Turgay Trough, the Santonian-Campanian spores and pollen. sediments are represented by the Eginsayskaya In the Maastrichtian Zhuravlevskaya Formation and Ayatkaya Formations. Thickness and posi­ cephalopods (belemnites) and foraminifera tion of these deposits are dependant on the telief (Gaudryina rugosa spinulosa assemblage) are pre­ on which they were lain and the dynamics of sent. Interlayering of silicified calcareous silt­ coastal marine deposition. The Eginsayskaya stones and opokas (siliceous mudstones) are Formation tanges, in thickness from 5-150 m, is found thtoughout its thickness of 6.0 m. A sandy widespread reflecting coastal, shoreline and marl with a thickness of 5.0 m contain cephalo­ lagoonal deposits. The Ayatskaya Formation is pods (belemnites) and foraminifera of found only in isolated ateas (Ayat river near Spiroplectammina kasanzevi assemblage. Marine Taranovskoe, Sokolovsky and Sarbaysky quarries Paleogene deposits lie conformably above the near Rudnyi city in Kustanay area) and reflects Zhuravlevskaya Formation. lagoonal sediments that are gradually replaced by the marine rocks of the Eginsayskaya Formation. The Ayatskaya Formation lies on 0.6-3 m of The Eginsayskaya Formation is best exposed in conglomerates and sandstones. Deposits up to the Kachar quarry (Fig. 6). The Novokozyrev- 7 m are dark-grey, green-grey glauconite quartz skaya Formation overlies continental Jurassic rich siltstones with spotes and pollen, indicating deposits. The formation is Ceno-manian in age, an early Santonian age. Mollusca from the determined by spores and pollen. The sedimen­ Inoceramus cardissoides Zone (early Santonian) tary rocks include interlayering of grey-pink are found in coarse glauconite sandstones with clays, multicoloted silty clays, silty bauxite, black beidellite-montmorillonite-halloysite clays with and brown lignite, and viscous grey clays. The sideritic and iron-ore concretions (1.5-5 m). This total thickness is 11.3 m. is followed by 2 m of green grey to yellow siltstones and fine grained poorly cemented An unnamed 15.8 m group of rocks overlies the sandstones and 1.5 m of dark beidellite- Novokozyrevskaya Formation. It is analogous to montmorillonite-halloysite clays with gypsum,

GEODIVERSITAS • 1997 • 19(2) 305 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

siderite and iron ore concretions. A red to yellow In the eastern margin of the eastern PriCaspian brown, yellow green oolitic iron ores in sands Zone, Maastrichitian deposits are widespread. and clays is approximately 1-2 m just before a The early Maastrichtian sediments are transgres- stratigraphic unconformity. Campanian sedi­ sively occurring on Campanian rocks and com­ ments of fine to medium grained diagonally bed­ posed of chalk, chalky limestone with belemnites ded sandstones with mollusca make up 2 m. It of Belemnella lanceolata Zone, Belemnella sumen­ contains late Campanian fossils of Pyconodonta sis sumensis Zone; foraminifers of Angulo- sp., P. cf. hippopodium, Acutostrea cf. acutirositris, Inoceramus sp., /. cf. balticus and foraminifers of Spiroplec-tammina optata Zone. Santonian interval contains the spores and pollen of SPA IV; foraminifers of Ammobaculites dignus- Pseudoclavulina hastata admota Zone, as well as the bivalves of Turgayan Inoceramus cardissoides Zone (early Santonian) and selachians of Squalicorax santonicus Zone and Squalicorax papulovi Zone (early Santonian), selachians of Squalicorax kaupi Zone. Campanian interval contains the spores and pollen association SPA IV.5; selachians of Squalicorax lindstromi Zone (early Campanian); Squalicorax plicatus Zone (early Campanian); Squalicorax ex gr. pris- todontus Zone (late Campanian); radiolarians of Prunobrachium crassum Zone (early Campanian), Amphipyndax stocki Zone (late Campanian); fora­ minifers of Spiroplectammina senonana pocurica Zone (early Campanian); Spiroplectammina opta­ ta Zone (late Campanian), Bolivina kalinini- Brotzenella taylorensis Zone (late Campanian) (Amon 1987).

MAASTRICHTIAN (Figs 3-6) The western portion of the Primugodzharie and Aktyubinskian Priuralie marine deposits of Maastrichtian age are represented by a calcareous clay marl of the Zharskaya Formation. A total thickness of 15 m of light grey siltstones and marls contain phosphoritic concretions throu­ ghout the deposit. Marls in the lower part of the section contain belemnites of Belemnella lanceo- lata Zone, Belemnella sumensis sumensis Zone, Belemnella sumensis pristodontus Zone; it contains also foraminifers of Angulogavelinella gracilis Zone, Brotzenella complanata Zone and Bolivinoides draco draco Zone. Marls of the upper I Siliceous Sandy Claystone part of the formation contain belemnites of Clay Si listone Neobelemnella kazimiroviensis Zone; mollusca of Oxytoma danica Zone and Pseudotextularia ele- FIG. 7. - Columnar section of the Kachar quarry reference sec- gans Zone. lion.

GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

gavelinella gracilis Zone, Brotzenella complanata fers of Brotzenella praeacuta Zone and Zone and Bolivinoides draco draco Zone; thick­ Hanzawaia ekblomi Zone (late Maastrichtian) ness is 30-60 m. Upper Maastrichtian sediments, (Amon 1987). ranging from 12-80 m thick, are represented by the same rocks with belemnites of Neobelemnella kazimiroviensis Zone; mollusca of Oxytoma dani- SUMMARY ca Zone; foraminifers of Brotzenella praeacuta 'Lone, Pseudotextularia elegans Zone (Naidin et al. During the Ctetaceous, microfossils are impor­ 1991). tant to correlate on a global and intetregional In northern PriAralie and south-western Turgay, scale, especially in the Peri-Tethys atea (Amon & Maastrichtian deposits are transgressively deposi­ De Wever 1994). The correlation proposed by ted on Santonian-Campanian rocks or Paleozoic Koch (1977) is mainly valid for western and rocks. They are represented by marls, chalks, north-western Europe. The zonal scale based on clayey siltstones, calcareous siltstones, sands and ammonite and belemnite zonation is only valid sandstones, cemented by calcareous clay. for European Russia, Ukraine, Byelorussia, Mollusca, belemnites and btachiopods can be Moldavia, and southern adjacent countries found within the 30-50 m thick formation. Early (Zhamoida 1989, 1994). The zonation shown in Maastrichtian deposits contain belemnites of figures 5 and 6 can be used in the southern Urals Belemnella lanceolata and fotaminifers of to help correlate to the East European platform Gaudryina rugosa spinulosa Zone. The foramini- during the Cretaceous. The regional stratigraphy fera zone can be correlated to deposits in the and correlation are summarized in figures 3 and 4. Magyshlak and PriCaspian depression. The Late Maastrichtian deposits contain belemnites of the Neobelemnella kazimiroviensis Zone and forami­ Acknowledgments nifers of Spiroplectammina kasanzevi Zone, This work has been supported by the Peri-Tethys which can also be correlated to the Magyshlak ptogramme (projects No. 95-10, 95-18 and and PriCaspian depression. 95-19). We are gratefull to Dt. Jean-Pierre In the Turgay area, the Maastrichtian deposits Bellier, Université Paris VII, France and Sylvie include calcareous sandstones and silty clays, cal­ Crasquin-Soleau, CNRS, UPMC Paris VI, careous siltstones, marl, quartz-glauconite sands France, who helped us to improve the manus­ and sandstones of the Zhuravlevskaya cript. Formation. This formation ranges in thickness from 5-85 m and is rarely found in outcrops except in the river valleys of the western portion of the Turgay trough. The Kachar quarry (Fig. 7) and Ayat River sections are the best reference sec­ REFERENCES tions. Thick Paleogene deposits cover most of Amon E. O. 1987. — The association of bivalves the Zhuravlevskaya Formation. ftom Late Maastrichtian deposits of Zhuravlev­ The Zhutavlevskskaya Formation contains early skaya Formation of Ayat River area (North- Maastrichtian spores and pollen of the SPA IV.6 Western margin of Turgay trough), in Puchkov and rare belemnites of the early Maastrichtian V. N. (ed.), New data on geology of the Urals, Belemnella sumensis Zone. Mollusca of the Urals Scientific Center of USSR, Academy of Sciences Publications, Sverdlovsk: 105-109 [in Oxytoma uralica Zone is found in the north-eas­ Russian]. tern portion of the Turgay trough. Radiolarians — 1988. — New data on sttatigraphy of Upper of the Orbiculiforma renillaeformis Zone and Cretaceous deposits of the north-eastern part of foraminifers of the Gaudryina rugosa Zone reflect Turgay trough. Geology and geophysics Dep. early Maastrichtian. VINITI, N8516-V88, Novosibirsk: 2-13 [in Russian]. Late Maastrichtian intervals contain belemnites — 1990. — Stratigtaphy of Ctetaceous deposits of of Neobelemnella kazimiroviensis Zone, foramini­ the Zautalie based on radiolarians. Geology andgeo-

GEODIVERSITAS • 1997 • 19(2) 307 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

physics Dep. VINITI, N6456-V90, Novosibirsk: Nauka Publication, Moscow, 202 p. [in Russian]. 2-12 [in Russian]. Papulov G. N. & Naidin D. P. 1979. — Boundary Amon E. O. & De Wever P. 1994. — Upper between Santonian and Campanian on Cretaceous biostratigraphy of the borders of the East-European platform, Transactions of Inst. Ural Belt: Western Siberian and Eastern Geol. Geochem. of the Urals Scientific Center of Volga-Ural basins: 299-262, in Roure F. (ed.), USSR Acad. Sci., volume 148. Urals Scientific Peri-Tethyanplatforms. Edition Technip, Paris. Center of USSR Academy of Science Publication, Azbel A. Y. & Grigyalis A. A. 1991. — Practical Sverdlovsk: 3-117 [in Russian]. manual on microfauna of the USSR, volume 5. Papulov G. N., Zhelezko V. I. & Levina A. P. Mesozoic foraminifers. 1991. Nedra Publication, 1990. — Upper Cretaceous deposits of Southern Leningrad, 375 p. [in Russian]. Zauralie (the Verkhnee Pritobolie area). Urals Gerasimov I. P., Koma A. R & Chikishev A. G. Branch USSR Academy of Science Publication, 1968. — Urals and the Cis-Urals. Nauka Sverdlovsk: 83-106 [in Russian]. Publication, Moscow: 5-460 [in Russian]. Shilin P. V. 1986. — Late Cretaceous floras of the Koch W. 1977. — Biostratigraphie in der Oberkreide Kazakhstan, systematic content, history of evolution, und Taxonomie von Foraminiferen. Geologisches stratigraphie significance. 3-136 [in Russian]. Nauka Jahrbuch, Reiche A, Heft 38: S.l 1-123. Publication, Alma-Ata. Miletsky B. E. 1981. — Geologic map of the-Kazakh Sobetski V. A. 1982. — Atlas on the invertebrates of SSR scale 1:500,000. Series Turgay-Mugodzharian. Late Cretaceous seas of PriCaspian depression, Explication note: 3-227 [in Russian]. Alma-Ata. Transactions of Paleont. Inst, of USSR Acad. Sci., Moskvin M. M. 1986. — Stratigraphy of the USSR. volume 187: 3-252 [in Russian]. Nauka Cretaceous System, semi-volume 1: 5-339 [in Publication, Moscow. Russian]. Nedra Publication, Moscow. Vereschagin V. N., Ronov A. B. & Tazikhin N. N. — 1987. — Stratigraphy of the USSR. Cretaceous 1975. — Paleogeography of the USSR. Explication System, semi-volume 2: 5-326 [in Russian]. Nedra note to the Atlas of lithologic-paleogeographic Publication, Moscow. maps of the USSR. Volume 3. Triassic, Jurassic Naidin D. P. & Kopaevitch L. F. 1977. — To zonal and Cretaceous periods: 5-200 [in Russian]. Nedra dividing of Upper Cretaceous of European Paleo- Publication, Moscow. biogeographic Belt. Bulletin of Moscow Society of Yanshin A. L. 1953. — Geology of the Northern Naturalists, Moscow, volume 52, No. 5: 92-112 [in PriAralie. Materials of Moscow Society of Russian]. Naturalists, new series, volume 15 (19): 3-736 [in Naidin D. P., Benjamovsky V. N. & Kopaevitch L. F. Russian]. Moscow University Publication, Moscow. 1984a. — Scheme of biostratigraphie dividing of — 1971. — Geology of the USSR. Volume XXI. Upper Cretaceous of European Paleobiogeographic Western Kazakhstan- Part 1. Geologic description, Belt. Bulletin of Moscow State University, Moscow, book 1: 7-879 [in Russian]. Nedra Publication, section 4 geology, No. 5: 3-15. [in Russian]. Moscow. — 1984b. — Methods of study of transgressions and Zakharov A. M. & Udris K. P. 1971. — Geology of regressions on example of Late Cretaceous basins of the USSR. Volume XXXIV. Turgay trough. the Western Kazakhstan Moscow State University Geologic description, book 1: 7-534 [in Russian]. Publication, Moscow, 162 p. [in Russian]. Nedra Publication, Moscow. Naidin D. P., Benjamovsky V. N., Segedin R. A., Zhamoida A. I. 1989. — Decisions of the Akopov T. R., Chen Len Son B. I. & Gorovoy Interdepartmental Stratigraphie Committee and it I. N. 1991. — Upper Cretaceous suites in permanent commissions, volume 24, VSEGEI East-Caspian and Cis-Mugodzharian. Bulletin of Publication, Leningrad: 5-74 [in Russian]. Moscow Society of Naturalists, Moscow, volume 86, — 1994. — Decisions of the Interdepartmental No. 1: 46-60 [in Russian]. Stratigraphie Committee and it permanent com­ Naidin D. P., Pokhialaynen V. P., Katz Yu. I. & missions, volume 27, VSEGÈI Publication, Krasilov V. A., 1986. — Cretaceous Period. Saint-Petersburg: 5-67 [in Russian]. Paleogeography and paleoceanology. Nauka Zhelezko V. I. 1987. — An Aktyubinskian phospho­ Publication, Moscow, 260 p. [in Russian]. rite-bearing basin. Urals scientific Center of USSR Nevesskaya L. A. 1985. — Bionomy of Late Creta­ Academy of Science Publication, Sverdlovsk: 3-51 [in ceous seas of Eastern part of PriCaspian depression: Russian]. 3-224 [in Russian]. Nauka Publication, Moscow. — 1988. — Selachiazones of the Santonian and Ozhiganov D. F. 1964. — Geology of the USSR. Campanian of South Urals and Mugodzhary, in Volume XIII. Bashkirian ASSR and Orienburg Chuvashov B. I. (ed.), Biostratigraphy and Iitholo- region. Part I, geologic description: 7-652 [in gy of the Upper Paleozoic of Urals, Urals Branch of Russian]. Nedra Publication, Moscow. USSR Academy of Science Publication, Sverdlovsk: Papulov G. N. 1974. — Cretaceous deposits of the 117-131 [in Russian]. Urals (stratigraphy, paleogeography, paleotectonics). Zhelezko V. I. & Segedin R. A. 1972. — New data

308 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

on stratigraphy of Cretaceous deposits of the Transactions of Inst. Geol. Geochem. of Urals Aktyubinskian-Primugodzharian area of Western Scientific Centet of USSR Acad. Sei., volume 96. Kazakhstan, in Papulov G. N. & Sitnikova. Z. I. Urals Scientific Center of USSR Academy of Science, (eds), Platformic formations of the Urals, Publication, Sverdlovsk: 18-28 [in Russian],

Submitted for publication on 15 December 1995; accepted on 15 September 1996.

APPENDIX

CONTENT OF BIOSTRATIGRAPHIC Actinocamax sp., A. ex gr. verus Mill., A. verus ZONES fragilis Arkh., Belemnitella sp, B. ex gr. praecur­ sor Stoll., B. praecursor praepraecursor Naid., B. praecursor media Jel. BELEMNITES Goniocamax lundgreni uilicus Zone: Actinocamax sp., A. ex gr. verus Mill., A. verus • Neobelemnella kazimiroviensis Zone: fragilis Arkh., Goniocamax ap., G. lundgreni Neobelemnella kazimiroviensis (Skolozdr.), uilicus (Kolt.). Belemnella sp., B. sumensis sumensis Jel., B. Goniocamax lundgreni lundgreni Zone: sumensis praearkhangelskii Naid. Goniocamax sp., G. intermedius (Arkh.), G. ex • Belemnella sumensis sumensis Zone: Belemnella gr. lundgreni (Stoll.), G. lundgreni lundgreni sp., B. ex gr. sumensis Jel., B. sumensis sumensis (Stoll.). Jel., B. ex gr. lanceolata (Schiodi.). Goniocamax intermedius Zone: Goniocamax • Belemnella lanceolata Zone: Belemnella sp, sp., G intermedius (Arkh.). B. ex.gr. lanceolata (Schloth.), B. lanceolata (Schiodi.), B. ex gr. sumensis Jel. • Belemnella licharevi Zone: Belemnella sp., MOLLUSCA B. licharevi Jel. • Belemnitella ex gr. langei Zone: Belemnitella • Oxytoma danica Zone: Teniupteria argentea ap., B. langei langei Schatsk., B. langei minor (Conrad), Oxytomadanica (Ravn). Jel., B. langei najdini Kon. • Oxytoma uralica Zone: Chlamys pulchellus • Belemnitella mucronata mucronata Zone: (Nilss.), Pycnodontevesiculare (Lam.), Oxytoma Belemnitella sp., B. ex gr. mucronata (Schloth.), uralica Glazun. B. mucronata mucronata (Schloth.) Aridi. • Inoceramus balticus Zone: Inoceramus balticus • Belemnellocamax mammilatus-Belemnitella Boehm., Pycnodontehippopodium (Nilss.), mucronata alpha Zone: Actinocamax sp., Acutostrea aff. acutirostris (Nilss.), Chlamys Belemnellocamax mammilatus (Nilss.), Paracti- spp., Dianchora labiata (Wahl.) nocamax ex gr. grossouvrei (Janet.), Belemnitella ' • Inoceramus azerbaidjanensis Zone: Inoceramus sp., B. mucronata mucronata (Schloth.), sp., In. azerbaidjanensis Aliev. B. mucronata alpha Schatsk. • Oxytoma tenuicostata Zone: Sphenoceramus • Actinocamax laevigatus-Belemnitella praecursor angustus (Beyenburg), S. papulovi Atabekjan, mucronatiformis Zone: Actinocamax sp., S. cf. lingua (Goldf.), Inoceramus cycloides A. laelligatus Arkh., Paractinocamax ex gr. gros­ Wegner, Oxytoma tenuicostata (Roem.), souvrei (Janet.), Belemnitella sp., B. praecursor Pycnodonte vesiculare (Lam.), Gryphaeostrea media Jel., B. praecursor mucronatiformis Jel. lateralis (Nilss.), Lopha semiplana (Sow.), • Belemnitella praecursor praepraecursor Zone: Acutostrea curvirotris (Nilss.).

GEODIVERSITAS • 1997 • 19(2) 309 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

• Inoceramus cardissoides Zone: Inoceramus car- vi Zhel., Eostriatolamia aktobensis Zhel., dissoides Gold-E, /. pachti Arkh., Korobkovi- Scapanorhynchus temirensis Zhel., Ptichocorax trigonia amudariensis (Arkh.), K. tobolica dolloi (Leriche), Ptychodus deccurrens Ag. Pojark., Cblamys faujasi (Deft.). • Squalicorax santonicus Zone: Squalicorax santo- • Inoceramus schloenbachi Zone: Inoceramus sp., nicus Glueck. et Zhel., Ptychocorax dolloi /. ex gr. kleini Muell., I. shloenbachi Boehm. (Leriche), Microanacorax praeyangaensis • Inoceramus labiatus Zone: Inoceramus cuvieri Glueck., Eostriatolamia ex gr. venusta Sow., /. labiatus Schloth., /. lamarcki Park., (Leriche), Cretoxyrhina mantelli (Ag.), /. websteri Mant., Piacenti cerasplacenta Dekay, Pseudocorax laevis Leriche. P. arkhangelskii Iljin, Collignoniceras woolgari • Squalicorax falcatus Zone: Squalicorax falcatus Mant. (Ag.), Microanacorax ex gr. praeyangaensis • Kamaroites grossouvrei Zone: Kamaroites sp., Glueck., Eostriatolamia ex gr. venusta K. aff. subtilis (Iljin), K. grossouvrei (Sem.), (Leriche), Ptychodus ex gr. venusta Dixon. K. mediasiaticum (Luppov), Schloenbachia • Squalicorax sagisicus Zone: Cretilamna appen- varians (Sow.), S. varians cf. fi'bramata (SowJ, diculata (Ag.), Squalicorax sagisicus Glueck., S. subvarians Spath., S. ventricosa Stieler, Acrolamna ex gr. crassicornis Zhel. Sciponoceras baculoides (Mant.), Mantelliceras • Palaeoanacorax intermedius Zone: Paleoana- mantelli (Sow.). corax intermedius Glueck., Eostriatolamia ex gr. • Oxytoma pectinata Zone: Inoceramus crippsi angustidens (Ag.), Scapanorhynchus ex gr. Mant., /. orbicularis Muenst., I. pictus Sow., raphiodon (Ag.). /. orbicularis Muenst., Oxytoma pectinata • Palaeoanacorax obliquus Zone: Paleoanacorax (Sow.), Entoliuri orbiculare (Sow.), E. noetlingi obliquus (Reuss.), Pseudoisurus semiplicatus (Sob.), Acutostrea delettrei (Coq.), Amphiodonte (Ag.), Eostriatolamia ex gr. subulata (Ag.), conicum (Sow.). Cretoxyrhina basalis (Giebel.). • Palaeoanacorax volgensis Zone: Paraisurus macrorhizus (Pict. et Camp.), Cretodus suloatus SELACHIANS (Gein.), Cretoxyrhina denticulata Glueck., Palaeoanaeorax volgensis Glueck., Hispidaspis • Squalicoraxpristodontus Zone: Squalicoraxpris- gigas (Woodw.). todontus (Ag.), Pseudocorax affinis (Ag.), Cretolamna borealis Prim. • Squalicorax ex gr. pristodontus Zone: FORAMINIFERA Squalicorax ex gr. pristodontus (Ag.), Pseudoisurus ex gr. laevis Leriche. Maastrichtian, Late 2 • Squalicorax plicatus Zone: Squalicorax plicatus • Pseudotextularia elegans Zone: Cibicidoides cli- (Priem.), Paraanacorax ex gr. obruchevi peatus (Vass.), Gavelinella danica (Brotz.), Glueck., Scapanorhynchus ex gr. raphiodon Hanzawaia ekblomi (Brotz.), Pseudotextularia (Ag.), Rbapbiodiscus texanus (Roem.). elegans Rzeh., Pseudotextularia varians Rzeh. • Squalicorax lindstromi Zone: Acrolamna acu­ minata dilatata Zhel., Protolamna arcuata Maastrichtian, Late 1 (Woodw.), Squalicorax lindstromi (David), • Brotzenella praeacuta Zone: Anomalinoides pin- Paraanacorax obruchevi Glueck., Eostriato- guis (Jenn.), Brotzenella praeacuta (Vass.), lamia lericbei Glueck. et Zhel. Cibicides kurganicus Neck., Gavelinella mid- • Squalicorax kaupi Zone: Acrolamna acuminata wayensis (Plumm.), Gavelinella pertusa (Ag.), Protolamna aduncata suberecta Zhell., (Marss.), Gavelinella welleri (Plumm.), Squalicorax kaupi (Ag.), Eostriatolemia segedini Globigerinelloides subcarinatus (Bronn.), Glueck. et Zhel., E. venusta (Leriche), Gyroidinoides giobosus (Hag.), Pseudouvigerina Scapanorhynchus raphiodon (Ag.). cristata (Marss.), Tappania seulmensis • Squalicorax papulovi Zone: Squalicorax papulo- (Cushm.).

310 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

Maastrichtian, Late, PriAralie Maastrichtian, Early 1 • Spiroplectammina kasanzevi Zone: Anomalin- • Angulogavelinella gracilis Zone: Angulogave­ bides Justus Podob., Brotzenella pseudopapilosa linella gracilis stellaria (Vass.), Bolivina decur- (Cars.), Bulimina rosenkrantzi Brotz., Hetero- rens (Ehr.), Bolivinoides delicatulus Cushm., stomella foveolata (Marss.), Quinqueloculina Bolivinoides peterssoni Brotz., Brotzenella taylo- fusiformis Putrja, Spiroplectammina kasanzevi rensis (Cars.), Cibicidoides bembix (Marss.), Dain. Gyroidinoides globosas (Hag.), Neflabellina praereticulata Hilt., Neflabellina reticulata Maastrichtian, Late 2, Turgay (Reuss), Osangularia navarroana (Cushm.). • Hanzawaia ekblomi Zone: Spiroplectinella sen- gibabensis (Bala-khm.), Gaudryina gigantica Maastrichtian, Early, PriAralie Subb., Angulogavelinella caucasica (Subb.), • Gaudryina rugosa spinulosa Zone: Ataxophrag- Hanzawaia ekblomi (Brotz.), Karreria fallax mium rimosum (Marss.), Bulimina quadrata Rzeh., Bulimina eminenta Ehtem., Gueblerina Plumm., Cibicidoides aktulagayensis (Vass.), robusta De Klasz. C. spiropunctatus (Gall, et Morr.), C. bembix bembix (Marss.), Dorothia pupoides ovata Maastrichtian, Late 1, Turgay Podobina, Gaudryina rugosa spinulosa Neck., • Brotzenella praeacuta Zone: Spiroplectammina Siphogaudryina stephensoni distincta Podobina, kasanzevi Dain, Arenobulimina oblique (Orb.), Spiroplectammina kelleri Dain, Spiroplectam­ A. presli (Reuss), Gaudryina rugosa rossica mina variabilis Neck., S. kelleri Dairi, Balakhm., Gaudryinopsis subbotinae (Kypr.), Valvulineria imitata Olss. Neoflabellina reticulata (Reuss), Valvulineria procera Podobina, V. imitata Olss., Gavelinella Maasttichtian, Early, Turgay midwayensis (Plumm.), Cibicidoides bembix • Gaudryina rugosa spinulosa Zone: Spiroplec­ kazakbstanica Neck., Brotzenella praeacuta tammina brevis modesta Kiss., Spiroplectinella (Vass.), Anomalinoides pinguis pinguis (Jenn.), variaspera (Kiss.), S. baudouiniana (Orb.), Nonionella kalinini Volosh., Reussella cimbrica Gaudryina rugosa spinulosa Neck., Siphogau­ (Troels.), R. bacilluma Ehrem., Bolivina incras- dryina stephensoni Cushm., Quinqueloculina sata gigantea Wicher, Bolivinoides peterssoni stolley Brotz., Lagena spp., Guttulina spp., (Brotz.), Rugoglobigerina rugosa (Plumm.), Discorbis parvus Ehrem., Angulogavelinella gra- R. macrocephala Btoun., Globotruncana hava- cilisstellaria Vass., A. praecaucasica (Vass.), nensis (Voorw.), Tritinella scotti Bronn., Hete- Valvulineria lenticula (Reuss), Stensioeinapom- rohelix navarroensis Loebl., Pseudoguem-bellina merana Brotz., Gyroidinoides turgidus (Hag.), kempensis Esker, P. palperba Bronn. et Brown. G. beresoviensis (Balakhm.), Osangularia nava- roana (Cushm.), Gavelinella welleri (Plumm.), Maastrichtian, Early 3 G. mira Podob., Cibicidoides voltzianus (Otb.), • Bolivinoides draco draco Zone: Bolivinoides C. spiropunctatus (Gall, et Morr.), C. bembix draco draco (Marss.),Coleites crispus Vass., (Marss.), Brotzenella complanata (Reuss.), Gavelinella midwayensis (Plumm.), Rugoglobi­ B. menneri (Kell.), Heterolepa orcina (Vass.), gerina rugosa (Plumm.), Spiroplectammina Cibicides globigeriniformis Neck., C. gankinoen- suturalis Kal. sis Neck., C. kurganicus Neck., Nonionellina spp., Rheinholdella brotzeni Olss., Epistomina Maastrichtian, Eatly 2 fax Nauss, Praebulimina carseyae (Plumm.), Bulimina spp., Bolivina incrassataincrassata • Brotzenella complanata Zone: Angulogavelinella Reuss, B. decurrens (Ehrenb.), Bolivinoides deco- ex gr. caucasica (Subb.), Anomalinoides ukrai- ratusdracoformis Vass., B. draco miliaris Hilt, et nious (Wolosch.), Bigiobigerinella biforaminata Koch., B. senonicus Dain, Pullenia kazakbsta­ (Hofk.), Bolivina inorassata crassa Vass., nica Dain, P. americana Cushm., Quadri- Brotzenella complanata (Reuss), Gavelinella morphina allomorphinoides (Reuss). welleri (Plumm.).

GEODIVERSITAS • 1997 • 19(2) 311 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

Campanian, Late 4 rina kelleri (Subb.), Bolivina kalinini Vass. • Brotzenella taylorensis Zone: Bolivina incrassata incrassata Reuss, Bolivinoides giganteus Hilt, et Campanian, Late 2, Turgay Koch, Brotzenella taylorensis (Cars.), Globo- • Bolivina kalinini-Brotzenella taylorensis Zone: truncana area (Cushm.), G. morozovae Vass., Spiroplectammina variabilis (Neck.), Plectina Gyroidinoides turgidus (Hag.), Heterostomella ruthenica (Reuss), Ataxophragirium compactum praefoveolata Mjatl., Orbignyna inflata (Reuss), Brotz., A. spongiosum Kriv. A. crassum caspium 0. acheri (Reuss), Pseudouvigerina cristata Vass., Orbignyna inflata (Reuss), 0. sacheri (Marss.), Rugoglobigerina kelleri (Subb.). (Reuss), Arenogaudryina granosa Podobina, Stensioeina pommerana Brotz. Nodosaria spp., Dentalina spp., Valvulinoides umovae (Kypr.), Globorotalites emdyensis Vass., Campanian, Late 3 G. michelinianus (Orb.), Gyroidinoides obli- • Bolivina kalinini Zone: Bolivina kalinini Vass., quaseptatus (Mjatl.), Eponides biconvexus Bolivinoides decoratus dracoformis Vass., Marie, Eoponidella linki Wick., Gavelinella cle­ B. miliaris Hilt, et Koch, Eponides frankei mentiana (Orb.) s.L, Brotzenella taylorensis Brotz., Gavelinella cayeuxi mangyschlakensis (Carsey), Anomalinoides falsiplanctonicus (Vass.), Gemelliides orcinus (Vass.), Globotrun- (Balakhm.), Bolivina kalinini Vass., B. plaita cana majzoni Sig. etDch., G. ventricosa White, Carsey, Bolivinoides decoratus decoratus (Jones), Rugoglobigerina rugosa (Plumm). B. laevigatas Marie, Globigerinelloides asper (Ehrenb.), Heterohelix globulosa (Ehrenb.). Campanian, Late 2 • Cibicidoides voltzianus Zone: Cibicidoides volt- Campanian, Late 1, Turgay zianus (Orb.), Gavelinella clementiana laeviga­ • Spiroplectammina optata Zone: Bathysiphon ta (Marie), Globorotalites emdyensis Vass., vitta Nauss, Thurammina papillata Brady, Globotruncana morozovae Vass., Heterostomella Ammodiscus giabratus Cushm. et Jarv., Haplo- praefoveolata Mjatl., Plectina ruthenica (Reuss), phragmoides ruidus crispus Podobina, H. cf. Sitella laevis (Beiss.) idonensis Podobina, Haplophragmium planum (Belous.), Spiroplectammina brevis Kiss., Campanian, Late 1 S. multiversurata Kiss., S. kelleri Dain, S. opta­ • Brotzenella monterelensis Zone: Ataxophrag- ta Kiss., Bolivinopsis rosula (Ehrenb.), Dorothia mium crassum caspiumVuss., Brotzenella men- pupoides (Orb.), Ataxophragmium rimosum neri (Kell.), Brotzenella monterelensis (Marie), (Marss.), Valvulineria laevie Brotz., Cibicidoides aktulagayensis (Vass.), Globotrun­ Gyroidinoides umbilicatulus (Orb.), Osangu- cana linneiana (Orb.), Haterostomella praefo­ laria cordieriana (Orb.), Eponides sibiricus veolata Mjatl., Orbignyna sacheri (Reuss), Neck., Cibicidoides eriksdalensis Brotz., Sitella carseyae (Plumm.), Voloshinovella lafittei C. aktulagayensis (Vass.), Brotzenella montere­ (Marie). lensis (Marie), Anomalinoides pinguis neckayae Vass., Allomorphina nonioninoides Dain. Campanian, Late, PriAralie • Cibicidoides aktulagayensis Zone: Ataxophrag- Campanian, Early 3 mium crassum caspium Vass., Orbignyna ovata • Cibicidoides temirensis Zone: Bolivinitella galea- Hag., Voloshinovella laffittei (Marie), ta Vass., Bolivinoides decoratus decoratus Jon., Heterostomella praefoveolata Mjatl., Eponides Bolivinoides 1 aevigatus laevigatas Marie, biconvexus Mane, E. frankei Brotz., Gavelinella Cibicidoides aktulagayensis (Vass.), Cibicidoides clementiana laevigata (Marie), Brotzenella montanus (Dol.), Cibicidoides temirensis (Vass.), monterelensis (Marie), B. taylorensis (Cars.), Eponides biconvexus Marie, Gavelinella dainae Cibicidoides aktulagayensis (Vass.), Globotrun­ (Mjatl.), Gavelinella stelligera Marie, cana area (Cushm.), G. morozovae Vass., Osangularia cordieriana (Orb.), Plectina. conver- Pseudcuvigerina cristata (Marss.), Rugoglobige­ gens (Kell.), Stensioeina pommerana Brotz.

312 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

Campanian, Early 2 Santonian, Late • Bolivinoides decoratus decoratus Zone: • Gavelinella stelligera Zone: Ataxophragmium Biglobigerinella algeriana Sig. et Ten Dam, orbignynaeformis Mjatl., Bolivinoides strigillatus Bolivinoides decoratus decoratus Jon., (Chapm.), Cibicides excavatus Brotz., Cibici­ Bolivinoides granulatus Hofk., Eponides mosk- doides eriksdalensis (Brotz.), Gavelinella costulata vini (Kell.), Gavelinella clementiana pseudoex- (Marie), G. ex gr. stelligera (Marie), G. stelligera colata (Kal.), Globigerinalloides volutus (Marie), G. umbilicatula (Mjatl.), Globorotalites (White), Orbignyna irreperta Wolosch. michelinianus (Orb.), Globotruncana bulloides Vogl., Osangularia whitei crassa (Vass.), 0. whi- Campanian, Early 1 tei polycamerata (Vass.), 0. whitei praeceps • Gavelinella clementiana clementiana Zone: (Brotz.), 0. whitei whitei (Brotz.), Praebulimina Bolivinoides laevigatas finitimus Vass., Dorothia ventricosa Brotz., Spiroplectam-mina rosala pupoides (Orb.), Neoflabellina rugosa (Orb.), (Ehr.), Stensioeina exculpta exculpta (Reuss), Gavelinella clementiana clementiana (Orb.), Stensioeina exculpta gracilis Brotz., S. granulata Gavelinella dainae (Mjatl.), Globigerinelloides perfecta Koch, Valvulineria mariei Vass. asper (Ehr.), Globigerinelloides clavatus Bronn., Globotruncana area (Cushm.), Neoflabellina Santonian, Turgay rugosa (Orb.), Reussellapseudospinulosa Troels., • Ammobaculites dignus-Pseudoclavulina hastata Stensioeina pommerana Brotz. admota Zone: Rhizammina sp., Bathysiphon vitta Nauss, Psammosphaera laevigata White, Campanian, Early PriAralie Saccammina spp., Ammodiscus cretaceus • Cibicidoides temirensis Zone: Ataxophragmium (Reuss), Reophax inordinatus Young, R. gutti- orbignynaeformis Mjatl., Stensioeina mursataen- formis Podob., Haplophragmoides tumidus sis Vass., S. pommerana Brotz, Eponides mosk- Podob., H. eggeri Cushm., Cyclammina flexuo- vini (Keller), Osangularia cordieriana (Orb.), sa Podob., Labrospira spp., Ammobaculites Gavelinella costulata (Marie), G. dainae dignus Podob., Ammosealaria incultus (Mjatl.), G. clementiana pseudoexcolata Kalin., (Ehrenb.), Pseudoclavulina sp., P. hastata Cibicidoides temirensis (Vass.), Bolivinoides admota Podob. decoratus decoratus Jon., B. laevigatas laevigatas Marie, Bolivinitella galeata Vass. Santonian, Early 2 • Stensioeina granulata perfecta Zone: Cibicides Campanian, Early Turgay excavatus Brotz., Cibicidoides eriksdalensis • Spiroplectammina senonana pocurica Zone: (Brotz.), Prkebulimina ventricosa (Brotz.), Rhabdammina cylindrica (Glaessn.), Bathy- Spiroplectammina rosala (Ehr.), Stensioeina gra­ siphon nodosariaformis Subb., Thurammina nulata incondita Koch, Stensioeina granulata splendens Egger, T. porosa Egger, Glomospira perfecta Koch, Valvulineria mariei Vass. corona Cushm. et ]&rv., G. gordialiformis Podob., Reophax proprius Podob., R. angustus Santonian, Early 1, upper part of late Coniacian - Belous., Adercotryma glomeratoformis (Zasp.), lower part of early Santonian Haplophragmoides giganteus Belous., Cribro- • Stensioeina exculpta exculpta Zone: Cibicidoides stomoides cretaceus exploratus Podob., C. trini- erikedalensis (Btotz.), Gaudryina laevigata tatensis sibiricus Podob., Labrospira fraseri Franke, Gavelinella infrasantonica (Balakhm.), propensa Podob., Ammobaculites fragmentarius Gavelinella umbilicatula (Mjatl.), Spiroplectam­ Cushm., Ammomarginulina crispa (Kypr.), mina rosala (Ehr.), Stensioeina exculpta exculp­ Spiroplectammina senonana pocurica Balakhm., ta (Reuss), Stensioeina granulata granulata Trochammina boehmi Franke, Gaudryinopsis (Orb.). vulgaris (Kypr.), Pseudoclavulinia hastata admota Podob. Coniacian, Late 2 • Stensioeina granulata granulata Zone: Eponides

GEODIVERSITAS • 1997 • 19(2) 313 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

concinnus planus Vass., Gavelinella costulata kelleri Vass., Praebulimina sp., Heterohelix spp. (Marie), G. infrasantonica (Balakhm.), G. thal- manni (Brotz.), Globorotalites michelinianus Coniacian, Eatly W Siberia (Orb.), Osangularia whitei whitei (Brotz.), • Haplophragmium chapmani-Ammoscalaria Spiroplectammina embaensis Mjatl., Stensioeina antis Zone: Ammobaculites dignus Podob., granulata granulata (Orb.), Valvulineria laevis A. fragmentarius agglutinans Podob., Ammoba­ Brotz. culoides unicus Tanach., Ammoscalaria antis Podob., Haplophragmium chapmani (Tapp.), Coniacian, Late 1 Spiroplectammina senonana orientalis Kiss. • Gavelinella costulata Zone: Gavelinella costula­ ta (Marie), G. infrasantonica (Balakhm.), Turonian, Late G. thalmanni (Brotz.), Osangularia whitei whi­ • Gavelinella moniliformis Zone: Ataxophrag- tei (Brotz.), Bolivinita eleyi (Cushm.), mium compactum Brotz., Gaudryina variabilis Spiroplectammina embaensis Mjatl., Stensioeina Mjatl., Gavelinella moniliformis (Reuss), granulata granulata (Orb.) Globorotalites multiseptus (Brotz.), Globotrun­ cana lapparenti Brotz., G. marginata (Reuss), Coniacian, Early Hedbergella agalarovae (Voss.), Reussella cari- • Gavelinella kelleri Zone: Bolivinita eleyi nata Vass., Spiroplectammina praelonga (Cushm.), Eponides concinnus Brotz., (Reuss.). Gavelinella kelleri (Mjatl.), G. praeinfrasanto- nica (Mjatl.), Globotruncana renzi Gand., Turonian, Late, W Siberia Gyroidinoides turgidus (Hag.), Reussella kelleri • Pseudoolavulina bastata bastata Zone: Vass., Stensioeina granulata kelleri Koch, Ammoscalaria antis Podob., Haplophragmoides Verneuilina muensteri Reuss. crikmayi Stelk et Wall., H. rota sibiricus Zasp., Pseudoclavulina bastata bastata Cushm., Coniacian, Turgay Textularia anceps Reuss, Trochammina arguta • Haplophragmium chapmani-Ammoscalaria Podob. antis-Reussella kelleri Zone: Ammobaculites dignus Podob., Ammobaculoides unicus Turonian, Early, W Siberia Tanach., Ammoscalaria antis Podob., Haplo­ • Gaudryinopsis filiformis angusta Zone: phragmium chapmani (Tapp.), Spiroplectam­ Ammobaculites tuaevi Zasp., Ammomarginu- mina senonana orientalis Kiss., Trochammina lina haplophargoidaeformis (Balakhm.), boehmi Franke, T. arguta Podob., Discorbis Gaudryinopsis filiformis angusta Podob., sibiricus Dain, Reussella kelleri Vass., Eponides Haplophragmium incomprehensis (Ehrem.), concinnus planus Vass., Gavelinella costulata Labrospira collyra (Nauss.), Lituotuba confusa (Marie), G. infrasantonica (Balakhm.), Zasp., Trochammina subbotinae Zasp., Heterohelix spp. Uvigerinammina manitobensis (Wiek.).

Coniacian, Zauralie Cenomanian, Upper, W Siberia • Discorbis sibiricus Zone: Arenobulimina sp., • Trochammina wetteri-Trocbammina subbotinae Nodosaria sp., N. zippei Reuss, N. bastata Zone: Ammobaculites tuaevi Zasp., Neobu- Schar., Dentalina sp., D. basiplanata Cushm., limina subcretacea (Cushm.), Reophax inordi- D. tineaformis Schar., Discorbis sp., D. sibiricus natus Young, Saccammina scruposum Berth., Dain, Stensioeina emscherica Baryschn., Thurammina papillata Brady, Trochammina Valvulineria lentioula (Reuss), Eponides sp., subbotinae Zasp., T. wetteri Stelk & Wall, E. incognitus Kypr., E. karsteni (Reuss), Uvigerinammina manitobensis (Wiek.). Gavelinella infrasantonica (Balakhm.), G. praeinfrasantonica (Mjatl.), G. sibirica Cenomanian, Lower and Middle Dain, Cymbalopora martini (Brotz.), Reussella • Gavelinella cenomanica Zone: Gavelinella bai-

314 GEODIVERSITAS • 1997 • 19(2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

tica (Brotz.), G. cenomanica cenomanica tica Lone: Cenodiscus cenomanious Aliev, (Brotz.), G. cenomanica concava (Vass.), Triadiscus lozyniaki Amon, Pentinastrum kur- Globigerinelloides bentonensis (Morr.), G. ultra- ganicum Amon, Spongotripus aculeatus Lipm., micrus (Subb.), Gyroidinoides nitidus (Reuss), Stichocapsa sp., St. ferosia uvatica Amon, G. subconicus (Vass.), Hagenowella chapmani Cryptamphorella conara (Forem.), Holocrypto- (Cushm.), Hedbergella caspia (Vass.), canium barbui Dumitrica. Hoeglundina postdorsoplana (Vass.), Lingulogavelinella bilamellosa (Balakhm.), Valvulineria lenticula lenticula (Reuss), V. len- SPORES-POLLENS ASSOCIATIONS ticula plummerae Loett. Maastrichtian, SPA IV.6: • dominants: Pinaceae, Taxodiaceae, Nermapolles RADIOLARIA Pf., Trudopollis Pf., T. nonperfectus Pf., T. spe- ciosus Pf.; Turgay • subdominants: Gleichenidites sp., Pinus sp., • Orbiculiforma renillaeforniis Zone: Orbiculi- P. aralica Bolch., Concavisporites sp., Mato- forma renillaeformis (Camp, et Clark), 0. aus- nisporites spp., Polypodiisporites Ep., Laevi- tralis Pess., 0. regis Pess., Crucella espartoensis gatosporites sp., Cyathidites sp., Cedrus sp., Pess., Tholodiscus fresnoensis (Forem.), Sticho- Casuarinidites sp., Priorités sp., Triporopol- capsa asymbatos (Forem.), Dictyomitra spp. lenites sp., Betulaepollenites sp., Kuprianipollis • Amphipyndax stocki Zone: Spongotrochus more- sp., Oculopollis sp., Plicapollis sp.; noensis Camp, et Clark, Orbiculiforma maxima • attendants: Classopollis sp., Gnetaceapollenites (Lipm.), Phaseliforma subcarinata Pess., sp., Ephedrites sp., Triporopollenites mutabilis Patellula verteroensis (Pess.), Ampbibracbium (N. Mtch.) Bratz., T. radiatostriatus (N. mucronatum Lipm., Prunobracchium articula- Mtch.), Triatriopollenites exelsus (R. Pot.), tum (Lipm.), Ampbimenium sibiricum Lipm., T rurensis Pf, Subtriporopollenites anulatus Pf., Theocampe sibirica Lipm., Amphipyndax stocki Vacuopollis spp., Nudopollis Pf., Extratriporo- (Camp, et Clark), Dictyomitra spp., Lithos- pollenites Pf, Mancicorpus N. Mtch., Aquila- trobus rostovzevi Lipm. pollenites Rouse et N. Mtch., Proteacidites • Prunobracbium crassum Zone: Spongopyle inso- Cook. rtCoup., TriprojectusN. Mtch.; lita insolita Kozur., Spongotrochus polygonatus • microphytoplankton abundant. (Camp, et Clark), Prunobracbium crassum (Lipm.), Ampbibracbium ornatum Lipm., Campanian, SPA IV. 5: Porodiscus cretaceus. Camp, et Clark, Botryo- • dominants: Gleicheniidites senonicus Ross., metra amazon (Forem), Theocampe animula G. laetus (Bolch.) Bolch., Plicifera delicata (Gorb.), Immersothorax marinas (Gorb.), (Bolch.) Bolch., Pinus sp., P. aralica Bolch.; Dictyomitra spp., Lithostrobus rostovzevi Lipm. • subdominants: Concavisporites sp., Matonispo- • Ommatodiscus mobilis 'Lone: Phaseliforma rites sp., Polypodiisporites sp., Laevigatosporites concentrica (Lipm.), Ommatodiscus mobilis sp., Cyathidites sp., Ariadnaesporites verrucatus Kozl., Spongodiscus spp., Orbiculiforma spp., (Elsik) Hills., Cedrus .sp., Casuarinidites sp., O. multa (Kozl.), Stylarta longispina Squin., Triorites sp., Triporopollenites sp.l Betulaepol­ Dictyomitra striata Lipm., D. torquata Forem. lenites sp., Kuprianipollis sp., Trudopollis rector • Stichocapsa pyramidata Lone: Cenosphaera sp., Pf, T. hemiperfectus Pf., T. parvotrudens Pf., C. magna Grig., Ellipsoxiphus asper Ruest, T. sp., Oculopollis sp., Plicapollis serta Pf., Trochodiscus spiniger Lipm., Spongodiscus spp. P. conserta Pf, P. sp.; Orbiculiforma spp. Stylotrochus dolichacantus • attendants: Appendicisporites sp., Cicatricosi- Lipm., Stichocapsa sp., St. pyramidata (Grig.), sporites sp., Hemitelia sp., Balmeisporites sp., Dictyomitra spp. Vacuopollis spp., Nudopollis Pf., Extratripo- • Cenodisous cenomanicus-Stichocapsa ferosia uva- ropollenites Pf., Postnormapolles Pf., Manci-

GEODIVERSITAS • 1997 • 19(2) 315 Amon E. O., Blueford J. R., De Wever P. & Zhelezko V. I.

corpus N. Mtch., Aquilapollenites Rouse et et Webst., Polypodiisporites flexus Chi., N. Mtch.; Retitricolpites spp., Tricolpites cf. reticulatus • rare: Camarozonosporites Kr., Taurocusporìtes Cook., T. erugatus Hedl. et Norris, Quercites reduncus (Boich.) Stover, Stenozonotriles radia- sparsus (Mart.) Samoil., Araliaceae, Rutaceae, tus Chi., Divisisporites eukirchenensis Th., Nyssapollenites sp., Polyporites clarus N. Mtch., Foraminisporis barangaensis (Nagy) Paci.; Monocolpites bisulcus Mart., Liliacidites sp., • microphytoplankton abundant. Disulcites reticulatus Pot., Ericipites sp.; • attendants: Camarozonnsporites ratus Kr., Santonian, SPA IV.4: C. spp., Concavisporites kainophyticus Voron., • dominants: Gleicheniidites senonicus Ross., C. junctum (K.-M.) Semenova, Kornilovites G. laetus (Boich.) Boich., Plicifera delicata crispus Kalm., K. trisegmentatus Kalm., (Boich.) Boich., Pinus sp., P. aralica Boich., Cicatricosisporites perforatus (Mart.) Voror., Cedrus parvisaccata Sauer, C. pisilla Sauer; C. exilioides (Mal.) Voron., C. dorogensis Pot. • subdominants: Concavisporites spp., Matoni- et Cell., Appendicisporites sp., Anemia sp., sporites spp., Polypodiisporites flexus Chi., Complexiopollis Pf., Kuprianipollis Kom., Laevigatosporites ovatus Wils, et Webst., Turonipollis Ameron, Tricolporopollenites Pf, Cyathidites australis Coup., C. minor Coup., Triantes; C. punctatus Dele, et Sprum., Cedrus pachider­ • microphytoplankton rare. ma. Sauer, Taxodiaceae, Casuarinidites cainozoi- cus Cook, et Rike, Triorites harrisii Coup., Late Cenomanian-early Turonian, SPA IV.2: Triporopollenites plieoides Zakl., Betulaepol- • dominants: Gleiheniidites sp., G. senonicus lenites microexelsus P. Rot., Scabratricolpites legi- Ross., G. laetus (Bolch.) Bolch., G. stellatus bilis Samoil., Kuprianipollis santaloides (Stelm.) (Bolch.), Plicifera delicata (Bolch.) Bolch., Kom., K. elegans (Zakl.) Kom., Complexiopollis Pinaceae, spp., Vacuopollis spp., V. pyramis Pf.; • subdominants: Cyathidites australis Coup., • attendants: Appendicisporites sp., Cicatricosi- C. spp., Hemitelia maxonii Ros., Matonia- sporites sp., Hemitelia mirabilis Boich., H. sepa­ sporites spp., Lygodium sp., L. japoniciforme rata Chi., H. sp., Balmeisporites rarus Kond., E. Iv., L. granulatum E. Iv., Contignisporites B. striatus Kond., B. sp., Thomsonipollis perplexus Sing., Laevigatosporites ovatus Wils. magnificus (Th. et Pf.) Kr., Concavipollis Pf., et Webst., Polypodiisporites flexus Chl., Multiporopollenites sp., Bombacacidites sp., Retitricolpites vermimurus Btenn., R. granosus Liliacidites sp., Monocolpites sp., Symplocacites Hedl. et Norris, R. vulgaris Pierce, Tricolpites sp., Proteacidites sp., Triporopollenites sp., cf. reticulatus Cook., T. erugatus Hedl. et Trudopollis sp.; Norris, Rousea micilipollis Srivast., Viburnum • rare: Camarozonosporites Kr., Taurocusporites sp., Quercites sparsus (Mart.) Samoil., Aralia­ reduncus (Boich.) Stover, Stenozonotriletes ceae, Rutaceae, Nyssapollenites sp., Polyporites radiatus Chi., Divisisporites eukirchenensis Th., clarus N. Mtch., Monocolpites bisulcus Matt., Foraminisporis barangaensis (Nagy) Pack; Liliacidites sp., Disulcites reticulatus Pot., • microphytoplankton abundant. Ericipites sp.; • attendants: Camarozonosporites ratus Kr., Turonian, SPA IV.3: C. spp., Concavisporites kainophyticus Voron., • dominants: Gleiheniidites spp., Selaginella C. junctum (K.-M.) Semenova, Kornilovites spp., Plicifera delicata (Boich.) Boich., crispus Kalm., K. trisegmentatus Kalrm., Pinaceae, Cicatricosisporites perforatus (Mart.) Voron., • subdominants: Taurocusporites reduncus C. exilioides (Mal.) Voron., C. dorogensis Pot. (Boich.) Stover, Cyathidites australis Coup., et Cell., Appendicisporites sp., Anemia sp., C. spp., Hemitelia maxonii Ros., Matonia- Complexiopollis Pf., Kuprianipollis Kom., sporites spp., Lygodium. spp., Contignisporites Turenipollis Ameron, Tricolporopollenites Pf., perplexus Sind., Laevigatosporites ovatus Wils. Triantes sp.;

316 GEODIVERSITAS • 1997 • 19 (2) Regional geology and stratigraphy, U. Cretaceous of southern Urals territories

• rare: Taurocusporites reduncus (Boich.) Stover, Cladophlebis foergeissenii (Heer) Vachr., C. kul- T. segmentatus Stover, Foraminisporis wontha- densis Vachr., Sphenopteris sp., Nissonia giensis (Cook. e^Dettm.) Dettm.; kazachstanica Vachr., Otozamites jarmolenkoi • microphytoplankton rare. Vachr., Zamites ? sp., Podosamites ellipsoides Sap., Sequoia beterophylla Velen., S. fastigata Early-middle Cenomanian, SPA IV. 1: Heer, Magnolia sp., Menispermites kryschtofovi- • dominants: Gleiheniidites sp., G. senonicus chii Vachr., Myrica ? kuldensis Vachr., M. zen- Ross., G. laetus (Boich.) Boich., Pinus, Cedrus, keri (Ett.) Heet., Platanus pseudoguillelmae Podocarpus, Dacridium., Phyllocladites; Krass., P. cuneiformis Krass, P. golenkinii, • subdominants: Dicksoniaceae, Cyatheaceae, Vachr., P. primaeva Lesq., P. newberryana Matoniaceae, Polypodiaceae, Lygodium sp., Heer., Dalbergites sewardiana (Shap.) Vachr., L. japoniciforme E. Iv.; D. simplex (Newb.) Sew., Leguminosites ovalifo- • attendants: Lophotriletes, Hymenozonotriletes, lius Heer, Acer janschinii (Vachr.) Vachr., Camarozonosporites, Concavisporites, Cicatri- Ziziphus menneri Vachr., Vitts cretacea Vachr., cosisporites sp., Appendicisporites sp., Anemia Cissites uralensis Krysht., Aralia formosa Heer, sp., Castanea vakhraneevi Boich., Tricolpites Diospyros primaeva Heer, Dicotylophyllum sagax Norris, T. albiensis Kemp., Cipuliferoi- rhomboidale Vachr. daepollenites minutus (Brenner) Sing., Platanus Aktyubinskian Priuralie, Western Primugod- orientaliformis Samoil., Menispermum turoni- zharie, Upper Albian-Cenomanian. cum N. Mtch., Quercites sparsus (Mart.) f. ves- So called Koldenen-Temirskian flora (according cus Samoil., Rhamnaceae; to Shilin, 1986). • rare: Cinguulatisporites eukirchensoides Dele, et Sprum., Taurocusporites reduncus (Boich.) Leafy flora assemblage LFA II: Stover, Peromonolites reticulatus Brenner, • Regnellidium sp., Taxites kasachstanica Shilin, Typha sp. Magnollia alternans Heer, M. amplifolia Heer, Laurophyllum sp., Platanus sp., P. pseudoguillel­ mae Krass., P. cuneiformis Krass., Celtidophyl- FLORA lum praeustrale Krass., Dalbergites simplex (Newb.) Sew., Ilex sp., Ziziphus ajatensis Leafy flora assemblage LFA I: Vachr., Diospyros primaeva Heer, Eucalyptus • Asplenium dicksonianum Heer, Onychiopsis psi- uralensis Vachr. lotoides (St. et Webb) Ward, Gleichenia sp., Turgay trough, Cenomanian-Turonian.

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