Stratigraphie correlation of the Upper Permian deposits from the south of the Cis-Ural marginal Trough and the adjacent areas of the Russian Plate

Ijia I. MOLOSTOVSKAYA Institute of Geology, Saratov State University, Moskovskaja street, 161, 410750 Saratov, (Russia)

Molostovskaya I. I. 1997. — Stratigraphie correlation of the Upper Permian deposits from the south of the Cis-Ural marginal Trough and the adjacent areas of the Russian Plate, in Crasquin-Soleau S. & De Wever P. (eds), Peri-Tethys: stratigraphie correlations, Geodiversitas 19 (2) : 247-259.

ABSTRACT Studied in detail were about 100 sections of the Upper Permian marine and continental deposits from the South Cis-Urals: from the south-eastern edge of the Russian Plate and the Cis-Ural Trough. Characteristic complexes of marine and non-marine ostracodes were distinguished. All the regional strati- KEYWORDS graphic units of the Upper Permian were characterized in detail from micro- Upper Permian, stratigraphy, paleontologic point of view. Associated organic remains were specified: correlation, tetrapods, bivalves, miospores. Brief lithologo-facies descriptions of the sec­ South Cis-Urals, tions from various structural zones are presented. Detailed correlations of the Cis-Ural Trough, Russian Plate. Upper Permian sections from the South Cis-Urals were carried out.

RESUME Une centaine de coupes dans les dépôts marins et continentaux du Permien supérieur du Cis-Oural sont étudiées en détail : de l'extrémité sud orientale de la plate-forme jusqu'à la dépression du Cis-Oural. Des assemblages d'ostracodes marins et continentaux sont distingués. Toutes les unités strati- MOTS CLÉS graphiques régionales sont caractérisées en détail du point de vue micropa- Permien supérieur, stratigraphie, léontologique. Les bio-restes associés sont spécifiés : tétrapodes, bivalves, corrélations, miospores. De brèves descriptions des faciès et de la lithologie sont présentées Sud Oural, pour les différentes zones structurales. Des corrélations détaillées pour les Cis-Oural, plate-forme russe. coupes du Permien supérieur sont conduites.

GEODIVERSITAS • 1997 • 19(2) 247 Molostovskaya I. I.

INTRODUCTION The present paper deals with stratigraphic corre­ lations and complex biostratigraphic description The Permian system is distinguished for the of the Upper Permian deposits from the southern wide-scale distribution of continental deposits in Cis-Urals, one of the most complicated geologic Gondwana and Laurasia. It is extremely difficult regions embtacing the junction zone of the to divide or correlate these deposits due to their south-east of the Russian Plate, Cis-Ural facial variations and scarcity of organic remains. Marginal Trough and Peri-Caspian Depression. The Upper Permian continental formations from Special attention was paid to ostracodes, which the east of European Russia are exceptional in formed the basis for section divisions and corre­ the respect, because diverse fossils have been lations. The research was founded on well and found and studied there: ostracodes, bivalves, natural section descriptions made by the authot conchostracans, tetrapods, fishes, flora and mio- in the process of geologic survey and thematic spores. Tetrapods and ostracodes are among wotks, and on the materials presented in the those most studied. Due to their common occur­ papers by Kuleva (1975) and Kochetkova rence and fast evolutionary variability, ostracodes (1970). Ostracode studies were performed by the have become the leading fauna in regional corre­ author. Besides the original material, definitions lations. They may prove to be important for dis­ by Kochetkova & Spirina (in Kuleva 1975) were tant stratigtaphic correlations as well. used, in some cases provided with new sttati-

FlG. 1. — The Upper Permian sections from the South-East of the Yergabusha River (P2t,). 47, Oslpovka, the Budenya the Russian Plate and Cis-Ural marginal deflection. P2u, (P2kz2). 48, Karatalka, the Teiryuk River (P2kz2). 49,

Uflmian; P2kz, Lower Kazanian; P2kz2, Upper Kazanian; P2t,, Rodnikovsk, the Teiryuk River (P2kz2). 50, Verkhotor, the Tor

sd Lower Tatariari; P2t2 , Upper Tatarlan (North Dvina horizon); River (P2kz2). 51, Voskresenskoye, the Tor River (P2t,). 52,

vl sd vl P2t2 , Upper Tatarlan (Vyatka horizon); T,, Lower Trlassic. Vesyoly, the Nugush River (P2t,, P2t2 , P2t2 ). 53, Krasnogorka, vl 1, Novo-Kandaurovka, the Chekushu - the Sukhalya River tribu­ the Nugush River (P2t2 ). 54, Lipovka (P2t2). 55, Alexandrovka, tary (P2u, P2kz,, P2kz2). 2, Korneyevka, the Sukhalya River the Nugush river (P2kz,, P2kz2, P2t,). 56, Yumaguzlno, the sd vl (P2kz2). 3, Yumaty, the Sukhalya River (P2kz,, P2kz2). 3", Meleuz (P2t2 , P2t2 ). 57, Kadyrovo, the Menyu River (P2t,). 58,

Talmasovo, the Bol. Kuyurgara River (P2kz,, P2kz2). 4, Malakanovo (P2kz,). 59, Sergeyevsklj, the Chukur - Bulyak

Yalchlkayevo, the Shaltanka River (P2u, P2kz,). 5, Well 104, River - the Bolshoj Yushatur tributary (P2t,). 60, Chernigovskij sd Byelozyorka, the Salmysh River (P2u, P2kz,, P2kz2). 6, (P2t2 ). 61, Bekechevo, the Nakuz River (P2kz,, P2kz2, P2t,). v1 Karmalka, the Salmysh River (P2kz,, P2kz2). 7, Well 124, 62, Savelyevsklj (P2t2 )- 63, Sankinskij (P2t2»'). 64, sd Petrovka (P2u, P2kz,, P2kz2, P2t,). 8, Well 122, Verkhni Gumbet Raznomolka, the Tugostemir River (P2t2 ). 65, Slavyanka

(P2u, P2kz,, P2kz2, P2t,). 9, Well 123, Voskresenskoye (P2u, (P2kz2, P2t,). 66, Allaberdlno (P2kz2). 67, Davletkulovo, the

sh P2kz,, P2kz2, P2t,). 10, Well 13 , the Shestimlr River (P2kz2, Yaman-Yushatyr River (P2kz2, P2t,). 68, Well 28 and well 43,

sh P2t,). 11, Well 12 , the Shestlmir River (P2u, P2kz,, P2kz2). 12, Davletkulovo (P2kz,, P2kz2, P2t,). 69, the Tashla River (P2kz2, sd Nizhni Babalar (P2kz,). 13, Well 388, Yanglz (P2u, P2kz,, P2kz2, P2t,). 70, Alexandrovka, the Kuplya River (P2t2 ). 71, Urman-

k sd P2t,). 14, the Shestimlr River (P2kz2, P2t,). 15, Well 152 , Tashla (P2t2 ). 72, Kastehnsklj, the Bolshol Yushatur River

Maryevka, the Salmysh River (P2u, P2kz,, P2kz2, P2t,). 16, basin (P2V). 73, Maslovsklj, the Bolshol Yushatur River basin k Well 157 , Maryevka (P2u, P2kz,, P2kz2). 17, Brody Spring (P2t2»'). 74, Smlrnovka (P2t2"). 75, Alebastrovaya (P2y). 76, k vl (P2kz2, P2t,). 18, Well 3, Brody (P2u, P2kz,). 19, Well 43 , Cherepanovka, the Burunchar River (P2t2 ). 77, Well 41,

Tiryak-Lizyak (P2u, P2kz,, P2kz2). 20, Well 48\ (State farm) Staroseika, the Bolshoi Ik River (P2kz,, P2kz2). 78, Staroseika sd Oktyabrsklj (P2kz2, P2t,). 21, Well 55, Budyonnovsklj (P2t,, (P2kz2). 79, Dmltriyevskij (P2t,, P2t2 ). 80, Well 4> and 5',

sd k sd P2t2 ). 22, Well 52 , Anatolyevka, the Salmysh River (P2u, Dmltriyevsklj (P2kz2, P2t,, P2t2 ). 81, Stary Kazlair, the Chena

k P2kz,, P2kz2). 23, Well 2 , Sakmara (P2u, P2kz,, P2kz2, P2t,). 24, River (P2kz2). 82, Novosyolki, the Chena River (P2t,). 83,

k k Well 1 , Sakmara (P2kz,, P2kz2). 25, Well 31 , Grebenl (P2kz,, Kholmogory, the Bolshoi Ik River (P2t,). 84, Novokulchumovo, sd P2kz2, P2t,). 26, Krasny Gully, Grebenl (P2u, P2kz,, P2kz2, P2t,j. the Sakmara River (P2t2 , P2t2»<). 85, Well 121,

k k 27, Well 5 , Grebeni (P2u, P2kz,, P2kz2). 28, Well 7 , Grebenl Novokulchumovo (P2kz2, P2t,). 86, Vyazovka, the Ural River

k sd (P2kz,, P2kz2). 29, Well 39 , Grebeni (P2kz,, P2kz2, P2t,). 30, (P2t2 , P2t2»'). 87, Well 102, Vyazovka, (P2kz2, P2t,). 88,

Well 6», Chebenki (P2kz2, P2t,). 31, Well 30, Nezhenka (P2u, Well 19«, Ostrovnoye, the Ural River (P2kz,, P2kz2, P2t,). 89,

k P2kz,, P2kz2, P2t,). 32, Orenburg (P2kz,). 33, Well 70 , Bolshoj Blumental Gully, the Burtya river (P2y, T,). 90, Zholtoye, the

k sd Sulak (P2kz,, P2kz2). 34, Well 94 , Bolshoj Sulak (P2u, P2kz,, Sakmara River (P2kz2). 91, Glryal, the Ural River (P2t2»", P2t2 ).

sd P2kz2, P2t,, P2t2 ). 35, Well 80, Dzhuan-Tyublnskaya (P2kz,, 92, Well 73, Actlvny (P2kz2, P2t,). 93, Well 44,

k P2kz2, P2t,). 36, Well 79 , Dzhuan-Tyubinskaya (P2u, P2kz,, Verkhneozernoye, the Ural River (P2kz,). 94, Verkhneozernoye

sd k P2kz2, P2t,, P2t2 , P2t2>«). 37, Well 98 , Karavanny (P,k2, T,). 38, (P2kz2, P2t,). 95, Wells profile 5-22, the Burly River (P2t„ PJtf,

1 1 Well 59 , Boyevaya Mt. (P2kz2). 39, Well 60 , Boyevaya Mt. P2t2v). (P kz,, P kz ). 40, Well 531, Boyevaya Mt. (P kz , P t,). 41, 2 2 2 2 2 2 a, outcrop exposure, b, well. C, boundary of the Cis-Ural margi­ Wells 61k-67k, Krasnoyarka (P kz,, P kz , P t,). 42, Well 73k, 2 2 2 2 nal deflection, d, boundary of Peh-Casplan Depression. A-B, Kamennaya (P u, P kz,, P kz , P t,, P t sd, P t vl). 43, 2 2 2 2 2 2 2 2 2 the line of the sections studied In Fig. 2. C-D, the line of the

Yelshanka (P \ *, T,). 44, Korneyevka, the Yarykly River (P2kz). 2 2 sections studied In Fig. 3. E-F, the line of the sections studied in 45, Yeldashevo, the Yurgashka River (P t,). 46, Skvorchlkha, 2 Fig. 4.

248 GEODIVERSITAS • 1997 • 19(2) Stratigraphie correlation of the Upper Permian, South Ural

GEODIVERSITAS • 1997 • 19(2) 249 Molostovskaya 1.1.

graphic interpretations. dominate in the section, marl, limestone and Bivalve complexes were studied by Kuleva dolomite interlayers are rare. Rock gypsification (1975), fish by Minikh & Minikh {in Ochev et is characteristically observed, significant in the al. 1979), conchostracans by Lopato {in Kuleva lower portion (Fig. 2). The thickness varies from 1975), miospores by Shatkinskaya (Efremov & 75 to 190 m. Diverse organic remains occur: Shatkinskaya 1972). Tetrapod definitions belong ostracodes, bivalves, conchostracans, miospores. to Tverdokhlebova, Chudinov & Ochev {in Ostracodes. Paleodarwinula abunda Ochev et al. 1979). The data on marine macro- (Mandelstam), P. angusta (Mandelstam), P. par- fauna was taken from the works by Kochetkova phenovae (Belousova), P. procera (Mandelstam), (1979) and Romanov (1972). P. lancetiformis (Kashevarova), P. trita (Palant), The wells were drilled by the Orenburg P. burjevoensis (Palant), P. lubimovae Territorial Geologic Service from I960 to 1985. (Kashevarova), Garjainovula lija (Spirina et Molostovskaya), G. kulevae (Spirina et Molostovskaya), G. gracilis (Spirina et UPPER PERMIAN DEPOSITS Molostovskaya), Prasuchonella stelmarta (Kashevarova), Pr. kargalensis (Kotshetkova), The upper section of the Permian system in the Pr. kamyschencaensis (Palant), Darwinuloides south of the Cis-Ural marginal bend and the djurtjuliensis Palant, Sinusuella pergrapbica adjacent region of the Russian plate is represen­ Mandelstam. ted by the Ufimian, Kazanian and Tatarian Bivalves. Palaeomutela attenuata Gusev, P. ova- stages. The Kazanian and Tatarian stages are each taeformis Gusev, P. sintasensis Gusev. represented by two substages: the lower and the Conchostracans. Hemicyeloleaia baentschiana upper ones. The lower substage of the Tatatian (Beyrich), Limnadia (Paleolimnadia) rossica consists of the Urzhum horizon, the upper one Molin. of the North Dvina and Vyatka horizons. Miospores. They are represented by two com­ According to the features of the Late Permian plexes: the early (Miospores HI) and the late sedimentogenesis, this territory is divided ones (Miospores H2) (Efremov & Shatkinskaja (Fig. 1) into three structural-facial zones: the 1972). Within the HI miospore complex domi­ western (Novo, Kandaurovka, Grebeni and nate Zonotriletes, significantly Disaccites, associa­ Yelshanka settlements), the axial (Raznomoika, ted Vittatina, characteristic Lycospora variabilis Vyazovka, Blumental) and the eastern (Tor, (Jansonius), Cirratriradites procumbens (Luber), Kholmogory, Burly). The principal stratigraphic Striatopodocarpites tojmensis Sedova, units from each zone possess lithologic composi­ Striatoidiplopinites elongaus (Luber), Vittatina tions, thicknesses and mineral complexes that striata Luber, Granisporites osmundae differ to various extents (Figs 1-4). (Samoilovich), Granulatisporites resistens (Luber), Cirratriradites procumbens (Luber), Platysaccus

THE UFIMIAN STAGE alatus (Luber), Striatohaplopinites perfectus The Ufimian stage from the western zone is stu­ (Naumova). died in exposures and cores from numerous The Ufimian beds are poorly studied in the cen­ mapping and pioneer wells (Fig. 1, Kandau­ tral zone due to little outcropping and the lack of rovka, Shestimir, Yangiz, Urnyak, Brody, core materials. A 180 m thick sequence of red Sakmara, Grebeni, etc.). gypsified clays, marls, sandstones with gypsum The stage is composed predominantly of red ter­ interlayers, situated a bit to the north of the area rigenous rocks that are replaced by halogenic concerned, near the village of Yar-Bishkadak Kungurian structures downwards along the sec­ (Kotschetkova 1970), has been assigned to the tion. The boundary between the Ufimian and Ufimian. The confirmed Ufimian beds to the Kungurian beds is conventionally drawn over the south, were penetrated by well 79 in the left- roof of the last more or less thick interlayer of bank region of the Ural River. They are represen­ chemogenic rocks. Clays, aleurolites, sandstones ted by red clays, aleurolites and sandstones.

250 GEODIVERSITAS • 1997 • 19(2)

Molostovskaya I.I.

Wells show the Ufimian beds to be up to 360 m The upper third of the sequence is built of clays, thick. In the eastern zone, the Ufimian deposits aleurolites and sandstones, the latter ones often occur along the Nugushu River (Vishnevskaya constituting up to 50-70% of its volume. The and Alexandrovka villages). They are represented substage thickness varies from 60 to 200 m. by a thick (about 700 m) sequence of red conglo­ Diverse organic remains occur within the lower merates with flint pebbles, sandstones, aleurolites Kazanian deposits: ostracodes, corals, bryozoans, and marls with rare thin limestone interlayers. crinoids. Coarse elastics are characteristic of the middle Ostracodes. Ostracodes are represented by the portion. Along the Nakyz river near the marine species: the guide fossil Amphissites tscher- Ryazansky Farm and the basins of the Bolshoj Ik dynzevi Posner and Pseudoparaparchites formida- and Bolshoj Syuren Rivers, the Ufimian deposits hilis Schneider, Aecuminella bella Khivintseva, are represented by thick pebble conglomerates Cornigella valosa Khivintseva, Kirkbya rara often changed by boulder ones. These conglome­ Khivintseva, Moorea facilis Schneider, Cavellina rates consist of coarse pebbles of diverse meta­ grandis Schneider, Cavellina unica Kotschetkova, morphosed and igneous rocks, limestones with Healdia postcornuta Schneider, H. oblonga Carboniferous faunal remains, quartz and flint. Kotschetkova, Healdia simplex Roundy, H. pseu- Sandstone lenses occur among conglomerates, disimplex Kotschetkova, H. subtriangula Kots­ and very seldom interlayers of marls and sulfur chetkova, H. reniformis Schneider, Healdianella silicified limestone (Kotchetkova 1970). vulgata Kotschetkova, Cribroconcha urschakensis In the vicinity of Zalair-Ilyinskoye and Starosejka Kotschetkova, Bairdia beedei Ulrich et Bassler, villages, the Ufimian deposits are represented by B. garrisonensis Upson, B. pompilioides Harlton, 68 m thick teddish-brown argillites with inter­ Acratia baschkirica Kotschetkova, Fabalicypris cre- layers of brownish-grey sandstones and grey pidalis Kotschetkova, Actuaria diffusa Schneider, limestones. The age of the sequence is establi­ A. secunda Kotschetkova, Monoceratina fastigiata shed according to ostracode complex: the zonal Kotschetkova, M. faveolata Kotschetkova, guide fossil Paleodarwinula abunda M. parvula Kotschetkova, M. exilis Schneider, (Mandelstam) and P. angusta Mandelstam, Fascianella notabilis Schneider. P. lancetiformis Kashevarova, etc. Foraminifers. Glomospira sp., Ammodiscus cf. bradynus Pandel, Verneuilinoides kasanica

THE KAZANIAN STAGE Ucharskaya, Cornuspira megasphaerica Gerke, The Kazanian stage according to its lithologic- C. microsphaerica K. M. Maclay, Calcivertella facial features is divided into two substages: the kasanica K. M. Maclay, Nodosaria cushmani lower and the upper ones. Paalzov, A', forcimeniformis K. M. Maclay, N. hexagona (Tscherdynzev), A^. aff. noinskyi The lower Kazanian stage Tscherdynzev, N. krotovi Tscherdynzev, Pseudo- The lower Kazanian stage has a complicated nodosaria lata K. M. Maclay, Frondicularia lon- structure within the area considered. In the west, gissima (K. M. Maclay), Fr. geinitzinaeformis it is represented by marine facies substituted by (K. M. Maclay), Geinitzina spandeli Tscher­ lagoonal-continental ones farther eastward, dynzev, Tetrataxis sp., Tristispermiana Gerke, etc. mainly in the axial zone; this reflects the trans- Brachiopods. Cleiothyridina pectinifera Sowerby, gressive-regressive cycle of the Kazanian sea CI. semiconcava Waagen, CI. reyssiana Keyserling, (Fig. 1, Urnyak, Brody, Sakmara, Grebeni, Stepanoviella hemisphaerium Kutorga, Nezhenka, etc.). Pr. (Cancrinella) cancrini Verneuil, Pr. konincki- Within the western zone, the lower Kazanian anus Keyserling, Licharewia rugulatia Kutorga, substage is composed of grey sandstones, aleuro­ L. curvirostris Verneuil, Dielasma elongata lites, clays and limestones. Clays and aleurolites Schlotheim, D. elliptica Netschajev, D. angusta dominate in the lowermost of the section; the Netschajev, Lingula orientalis Golowkinsky, Aulosteges horrescens Verneuil. middle part is represented mainly by limestones, marls and clays. Bivalves. Leibea hausmanni Goldfuss, Allorisma

252 GEODIVERSITAS • 1997 • 19(2) Stratigraphie correlation of the Upper Permian, South Ural

elegans King, Pseudobakewellia sulcata (Geinitz), limestones and marls. Within the section near Ps. ceratopbragaeformis Noinski, S. tutchburia Davletkulovo village, scattered small flint and tschernyschevi Licharev. marl pebbles occur as well as small lenses of fine- In the central and eastern zones, the lower pebble conglomerates. The substage is up to Kazanian comprises a sequence of grey-colored 600 m thick thete. The section near Ostrovnoye sandstones, aleurolites, clays, marls, limestones village is distinguished for thiner rocks; it is and dolomites of lagoonal-deltaic and littotal- 250 m thick. marine genesis (Figs 1, 2, 3, Davletkulovo, The upper Kazanian substage has a somewhat Bekeshevo, Starosejka, Ostrovnoye, Verkhneo- uneven structure in the eastern zone. At the Tor zernoye). The sequence contains the Kazanian River (Kotchetkova 1970), this is represented by complex of non-marine ostracodes: guide zonal a thick (556 m) catbonate-terrigenous sequence fossil Paleodarwinula fainae (Belousova) and composed of interlaid brown, lilac and grey P. cuneata (Kotschetkova), P. irinae (Belousova), clays, aleurolites, marls, limestones, sandstones. Prasuchonella belebeica (Belousova), Darwinu- The Kazanian is not divided into substages loides cf. sentjakensis (Sharapova). within the section along the Nugush River. Non-marine bivalves. Paleomutela sintasensis Assigned to it is a thick (over 700 m) sequence of Gusev, P. ovataeformis Gusev, characteristic of the brown, lilac, grey marls and aleurolites with Ufimian and Lower Kazanian deposits. sandstone interlayers; this sequence overlies a Flora. Pecopteris anthriscifolia Meyen, sand-conglomerate one, that is conventionally Sphenophyllum, Asterodiscus. considered to belong to the Ufimian stage. Pollen of cordaites: Cordaitina uralensis (Luber) Coarse elastics are rather significant near Samoilovich, C. cubrotata (Luber) Samoilovich. Zhyoltoye village: sandstones, gravelstones and Ginkgos: Ginkgocycadophytus erosus (Luber) conglomerates. The section near Novokul- Samoilovich. chimovo is represented by a rather monotonous Conifers: Protodiploxypinus elongatus interlayers of concretionary and bedded brown Samoilovich, Protopodocarpus alatus Samoilovich. limestones. Diverse organic remains occur within the upper Kazanian deposits ovet the whole of Some pollen of obscure systematic affiliation: the territory: ostracodes, bivalves, conchostra- Azonalites [Rugosind) tenuis Luber, A. (Tenuella) cans, tetrapods, flora and miospores. levis Luber. Ostracodes. Ostracodes are represented by the Fern-like spores: Azonotriletes cf. resistens Luber, following species: Paleodarwinula fainae A. osmundes Samoilovich (Kuleva 1975). (Belousova), P. alexandrinae (Belousova), P. ire- nae (Belousova), P. cuneata (Kotschetkova), The upper Kazanian substage P. tichonovichi (Belousova), P. tuimazensis The upper Kazanian substage in the western (Kotschetkova), P. varsanofievae (Belousova), zone is represented by lagoonal-continental for­ P. inornatinaeformis (Belousova), P. chramovella mations: red, less frequently grey clays, aleuro­ (Belousova), P. aronovae (Belousova), P. persim- lites, sandstones, and, to a smaller extent, by plex Kotschetkova, P. procurva (Kotschetkova), limestones, marls, dolomites (Yalchekayevo, the Garjainowula lija (Spirina et Molostovskaja), Shestemir Rivet, Shestemir, the Karmalka Spring, G. ex gr. gracilis (Spirina et Molostovskaja), Tashla-Urnyak, Sakmara, Grebeni, Nezhenka, Prasuchonella tichwinskaja (Belousova), P. bele­ etc.). The lower boundary of the late Kazanian beica (Belousova), Darwinuloides sentjakensis deposits is clear, drawn over the roof of marine (Scharapova), Placidea ex gr. lutkevichi sandstones, overlain by clays with the zonal guide (Spizharskyi). Schneideria kazanica Kotschetkova fossil Paleodarwinula fainae (Belousova). Its occurs only in the lower part of the section. thickness varies from 110 to 140 m. Bivalves. Bivalves are represented by the Belebej Within the axial zone (Davletkulovo, Slavyanka, complex : Palaeanodonta rhomboidea (Net- Islayevka, Ostrovnoye), the upper Kazanian sub- schaev), Palaemutela celebrata Gusev, P. quadrata stage is composed of non-marine interlaid clays, Kuleva, P. novalis Netschaev, P. umbonata aleurolites and sandstones with rare interlayers of

GEODIVERSITAS • 1997 • 19(2) 253 Molostovskaya I. I.

FIG. 3. — Correlations of the sections of the Upper Permian deposits in central part of Cis-Ural marginal deflection. 1, conglome­ rates. 2, Ural rocks pebbles. 3, local rocks pebbles. 4, sandstones. 5, aleurolites (siltstones). 6, clays. 7, marls. 8, limestones. 9, organogenic-clastic limestones. 10, nodular limestones. 11, dolomites. 12, gypsum. 13, anhydrites. 14, salts. 15, ostracodes. 16, bivalves. 17, conchostraceans. 18, brachiopods. 19, foraminifers. 20, gasteropods. 21, tetrapods. 22, fishes. 23, flora. 24, mio- spores.

254 GEODIVERSITAS • 1997 • 19(2) Stratigraphie correlation of the Upper Permian, South Ural

(Fischer), P. krotovi Netschaev, P. olgae Gusev, increases. The section near Davletkulovo village P. doratiformis Gusev. is composed of red interlaid clays and aleurolites, Conchostracans. Palaeolimnadiopsis eichwaldi sandstone, limestone and marl interlayers, thin (Netschaev), Clyptoasmussia exiqua (Eichwald), lenticular interlayers of fine-pebble conglomerates Cyclotungusites kazanensis Molin, Ulugkemia and gravelstones with their elastics consisting borisi Novojilov, U. orengurgiana Molin, U. petri mainly of flints. Unevenly scattered flint pebbles Novojilov, Sphaerestheria ikensis Molin, and gravels occur in some aleurolite intetlayers. A Pseudestheria kaslanica Molin. thick (6 m) interlayer of coarse-pebble conglome­ Tetrapods. Platyaps sp., Deuterosaurus sp., rate lies in the base of the section. The boundary Tapinocephalidae, similar in dimensions to between the Kazanian and Tatarian deposits is Deuterosaurus gigas Efremov. drawn over its rugged lower surface. The appa­ Miospores. Characteristic Cordaitina, Limiti- rent thickness - 430 m. The Urzhum horizon sec­ sporites leschikii Klaus, Gigantosporites hallsta- tion near the villages of Ostrovnoye and Vyazovka tbensis Klaus, Striatites marginalis Klaus, looks more monotonous and consists of finer Striatohaplopinites latissimus (Luber), Striato- rocks. It is over 550 m thick. The Urzhum hori­ piceites suchinensis Sedova, Vittatina striata Luber, zon is unevenly structured within the eastern associated Cyclogranisporites, Acanthotriletes, zone (Fig. 4). It is characterized by binary structu­ re in the north of the zone, in the sections along Azonaletes. the Tor, Yergabusha and Yurgashi rivers. Its lower Flora. Carpolithes sp., Phyllododerma sp., half consists of a conglomerate-sandstone sequen­ Noeggerathiopsis sp., Lepeophyllum sp., Samaropsis ce with rare interlayers of red-brown clays and sp., Paracalamites sp., Odontopteris sp., Equisetina marls. The upper one is represented by a sp., Rufloria sp., Taeniopteris sp., Recopteris sp., marl-clay-sandstone sequence with intetlayers of Voltzia mamadyschensis Zalessky, Samaropsis irre­ grey clayey limestones and aleurolites. The hori­ gularis Neuburg, Psygmophylum expansum zon is 780 m thick. Brongniart, Odontopteris cf. rossica Zalessky, Ullmannia biarmica Eichwald. Southwards, near the villages of Bekechevo, Dmitriyevo, Kholmogory, the Urzhum horizon

THE TATARIAN STAGE is dominated by interlaid clays, aleurolites, inter­ The Urzhum horizon layers of fine-grained sandstones and brown The lower Tatarian substage (Utzhumsky in concretionary limestones. Fine and coarse-pebble figures 2-4) in the western zone discontinuously and even boulder conglomerates are also impor­ overlies the Kazanian beds and is characterized tant. Their clastic material is poorly sorted. The by binary structure (Shestemir, Sakmara, pebble sizes vary from 1 to 10 cm, the boulders Grebeni, Nezhenka, Boyevaya Mt.). Its lowet are up to 20-25 across. Large pebbles and boul­ part is composed of obliquely layered red sand­ ders are represented by the Lower Permian and stones, aleurolites, clays and fine-pebble conglo­ Middle Carboniferous limestones and sand­ merates of local-rock pebbles. The upper half is stones; fine pebbles by flints. Conglomerates are built of red aleurolites, clays, fine and more sel­ usually found within the bases of sedimentation dom coarse-grained sandstones. The horizon is rhythms which are closed by clays with nodular up to 200 m thick. limestones. Conglomerate members in the lower This division in two parts becomes progressively part of the section are up to 8-10 m thick. less vivid eastwards (Kamennaya, Dzhuan- Upwards along the section, conglomerate mem­ Tyubinskaya). bers become thinnet and the sizes of clastic mate­ rials decrease (Kuleva 1975). The axial zone of the Urzhum horizon is distin­ Farthet south, towards the Peri-Caspian guished for high thicknesses, aleurolite-clayey Depression (Burly), and to the west of the Urals composition, conglomerate-lens occurrence and forefolds (Novokulchumovo), the sizes of clastic widely spread nodular limestones. The number material and the share of coarse-clastic rocks in of conglomerate interlayers reduces southwards the section decrease. The principal position in its (Fig. 3), the number of nodular limestones

GEODIVERSITAS • 1997 • 19(2) 255 Molostovskaya I. I.

structure is occupied by clays, aleurolites and rimus (Sauer), Striatoleachites, Jugasporites, fine-grained sandstones. The following features Faunipollenites, Jaeniasporites albertal Jansonis, are characteristic of these sections: rather mono­ Vittatina striata Luber; associated Platysaccus sp., tonous brown color of the rocks, scattered lime­ Alisporites striatohaplopinites. stone nodules, aleurolite predominance within the lower part of the section and that of clays in its The North Dvina horizon upper part. The apparent thickness of the Ur- The North Dvina horizon (Severodvinsky in zhum horizon section at Burly constitutes 960 m. Figs 2-4) in the western zone is represented by Ostracodes. The paleontologic description of interlaid red clays, aleurolites, sandstones, rare the Urzhum horizon is complete and involves lenses of fine-pebble conglomerates of mostly large variety of forms. Ostracodes are represented local rocks and isolated interlayers of brown by a rich complex consisting of the following clayey limestones (Budyonovsky, Ostrovnoye, species: zonal guide fossil Paleodarwinula fragili- Kamenny). formis (Kashevarova) and P. elongata (Lunjak), As in the western zone, the North Dvina horizon P. fragilis var. angusta (Schneider), P. inornatinae section in the south of the central zone is charac­ (Lunjak), P. chramovi (Glebovskaya), P. torensis terized by rather fine terrigenous composition (Kotschetkova), P. fab a (Mischina), P. impostor and red rock-color (well 73k Dzhuan- (Mischina), P. defluxa (Mischina), P. arida Tyubinskaya, Vyazovka). (Molostovskaya), P. obvia (Molostovskaya), The North Dvina horizon is ununiform in its P. gariainovi (Molostovskaya), Prasuchonella structure in the north of the central zone and in nasalis (Shatapova), Darwinuloides bugurusla- the eastern zone. It is variegated and characteri­ nicus Kashevarova, Sinusuella ignota Spizharskyi, zed by carbonate-clayey composition, being for­ Placidea lutkevichi (Spizharskyi). med of redrown, lilac, grey clays, aleurolites, All the species listed above are rather widely dis­ sandstones, limestones and marls. The interlayers tributed within the Urzhum horizon rocks over of grey rocks generally contain large amounts of the whole of the Russian Platform (Molostovsky charred plant detritus (Gumaguzino, Vesyoly, & Molostovskaya 1967; Molostovskaya 1974, Raznomoika, Chernigovsky, Alexandrovka on 1993). Besides, the upper part of the Urzhum the Kuplya River, Uman-Tashla, Dmitrovsky, horizon in the territory considered is characte­ Novokulchumovo, Giryal, Burly). In some sec­ rized by isolated localities of endemic cytherides: tions (Chernigovsky, Raznomoika, Dmitri- Tscherdynzeviana squamosa Kotschetkova, yevsky), coarse elastics (sandstones and conglo­ Wetluginella (?) tatarica Molostovskaya in press, merates) are rather significant in the horizon Kaschevaroviana delicata Molostovskaya in press, structure. They are generally associated with the K. pectunata Molostovskaya in press. lower half of the section, sometimes forming a Bivalves. Abiella subovata (Jones), Microdantella sequence up to 300 m thick there (Cherni­ microdonta (Khalfin), M. plotnikovskiensis govsky). The amount of coarse terrigenous mate­ (Fedotov), Palaemutela doratiformis Gusev, rial within the North Dvina horizon decreases P. parallelogramma Kuleva, P. gusevi Kileva, westwards and southwards from the Urals to the Anthraconaia verneuili (Amalizky), A. aktubensis Peri-Caspian Depression. The number of grey- Gusev, Anthraconauta (Prokopievskid) pseudophil- rock interlayers decreases in the same ditection. lipsi Fedotov. The thickness of the North Dvina horizon varies from 100 m (Ostrovnoye) to 670 m (Burly). Conchostracans. Pseudostheria angulata The rock ages within the North Dvina horizon (Lutkevich), Sphaerestheria belorussica Novojilov, are determined by numerous and multiform Triedrolophus tverdochlebovi Molin, Pseudostheria organic remains. otchevi Molin, Megasitum jaroslavlense Novojilov. Tetrapods. Mnemeiosaurus jubilaevi Novikov, Ostracodes. Ostracodes are represented by rich Melosaurus sp., Deuterosaurus sp., Platyops sp., and diverse associations. The following species Notosyodon sp. are ubiquitous: zonal guide fossil Suchonellina Miospores. Characteristic Lebachiacites pulcher- futschiki (Kashevarova) and S. inornata Spizhar-

256 GEODIVERSITAS • 1997 • 19(2) Stratigraphie correlation of the Upper Permian, South Ural

FIG. 4. — Correlations of the sections of the Upper Permian deposits in eastern part of Cis-Ural marginal deflection (legend see figure 3).

GEODIVERSITAS • 1997 • 19(2) 257 Molostovskaya I. I.

skyi, S. parallela Spizharskyi, 5. undulata quartz (Savelyevka, Sankinsky, Kasterinsky, Mas- (Mishina), S. daedala (Mishina), S. cultella lovsky, Ostrovnoye, Dzhuan-Tyubinskaya, Ka- (Mishina), S. degitalis (Mishina), S. spizharskyi mennaya, Yelshanka, Vyazovka, Blumental). Grey (Pozner), Prasuchonella stelmachovi (Spizharskyi), and greenish-grey conglomerates and sandstones P. sulacensis (Starozhilova), Darwinuloides bugu- in Blumental Gully are associated with copperore ruslanicus Kashevarova, Permiana elongata manifestations. All the rock there are characterized Posner, P. oblonga Posner, Tscherdynzeviana pyl- by large amounts of charred plant remains: equise- chra Belousova, T. buzulukensis Kashevarova. tite stem fragments, pieces of silicified wood. Besides the ostracode listed above, some peculiar The Vyatka horizon sections in the eastern zones sculptured endemic cytherides occur in the eas­ are dominated by brown and, more seldom, grey tern zone : Tscherdynzeviana busulucensis clays, aleurolites, sandstones. Grey, lilac, brown Kashevarova, T. pennata Kotschetkova, T. abscon- limestones and marls are also important. Some dita Kotschetkova, Netschajewiana costata conglomerates occur, forming rather large lenses Kotschetkova, Nuguschia sinizyni Kotschetkova, and interlayers. Their clastic material is represen­ Kaschevaroviana delicata Molostovskaya in press, ted by flints, quartz, limestones, effusive rocks K. pectunata Molostovskaya in press, Jungumulus and more seldom, local red rock (Vesyoly, mirus Molostovskaya in press, Permianella inila- Krasnogorka, Yumaguzino, Smirnovka, Aleba- terata Molostovskaya in press, Pamilio primaris strovaya, Cherepanovka, Novokulchu-movo, Molostovskaya in press. They are clearly different Giryal, Burly). The thickness of the Vyatka hori­ from those common for the Russian Platform in zon comprise 245 m near Novokulchumovo, their morphologic features, being close to marine 465 m near Vyazovka. and semimarine cythetides of the Triassic from The rocks from the Vyatka horizon contain the Peri-Caspian Depression. diverse organic remains. Bivalves. Bivalves are represented by Ostracodes. Ostracodes are represented by the Palaeomutela inostranzevi Amalizky, P. keyserlingi following species: guide fossil Suchonellina trape- Amalizky, Palaenodonta fischeri Amalizky, zoidea (Sharapova) and S, parallela Spizharskyi, Opokiella ignatjevi Gusev. S. undulata (Mishina), Wjatkellina fragilina Conchostracans. Siberioleaia oblonga (Belousova), W fragilis (Schneider), W. vladimi- (Mitschell), Hemicycloleaia intermediata rina (Belousova), Dvinella ex gr. cyrta (Zekina), (Mitschell), Pseudostheria cicatricosa (Novojilov). Suchonella typica Spizharskyi, Tatariella angulata Tetrapods. Chroniosaurus dongusensis Mishina, Placidea lutkevichi (Spizharskyi), Tverdochlebova, Rophanodon tverdochlehovae Tscherdynzevianapulchra (Belousova). Ivachnenko, Microphon exiquus Ivachnenko. Besides them, the sections from the eastern zone Fishes. Isadia aristoviensis A. Minich, /. sucho- bear endemic sculptured cytherides, conveyed nensis A. Minich, Toyemia tverdochlebovi Minich. from the North Dvina horizon Tscherdynzeviana Flora. Pursongia amalitzkii Zalessky, Cordaites pennata Kotschetkova, Netschajewiana costata clercii Zalessky. Kotschetkova, Kashevaroviana delicata Molostov­ Miospores. Limitisporites sp., Jugasporites sp., skaya in press, Pamilio primaris Molostovskaya in Lueckisporites virkkiae Potonie et Kremp, press. Taeniaesporites albertae Jansonius. Bivalves. Palaeomutela inostranzevi Amalizky, P. orthodonta Amalizky, P. ovalis Amalizky, The Vyatka horizon P. plana Amalizky, Palaeanodonta fisheri The Vyatka horizon (Vyatsky in Figs 2-4) in the Amalizky, P. okensis Amalizky, Opokiella tscherny- western and central zones, like the North Dvina schevi Plotnikov. one, is composed of terrigenous and mostly red Conchostracans. Limnadia angulidorsa rocks: clays, aleurolites and, to a smaller extent, Novojilov, L. maitschatica Novojilov, L. (Falsisca) sandstones. Rare thin conglomerate interlayers or furaica Novojilov, Megasitum kaljugense lenses occur, with their clastic material represented Novojilov, M. vanum Novojilov. by local-rock pebbles, more seldom by flints and Tetrapods. Chroniosuchus uralensis Tverdoch-

258 GEODIVERSITAS • 1997 • 19(2) Stratigraphie correlation of the Upper Permian, South Ural

lebova, Kotlassia sp., Raphanodon sp., Scutosaurus this territory and the Tethys matine plain in the sp., Inostrancevia uralensis Tatarinov, Scylaco- Tatarian age. suchus orenburgensis Tatarinov, Dicynodon cf. Thorough search for ostracodes in other regions amalitzkii Suschkin. should be considered a primary task aimed to Fishes. Isadia aristoviensis A. Minich, Wodnika distant correlations. invicta A. Minich.

REFERENCES

SUMMARY Efremov V. A. & Shatkinskaya E. F. 1972. — Spore- pollen complexes within the Ufimian rocks from the Salmysh dislocation zone in the Otenbutg Cis- All the Upper Permian stratigraphie units from Urals. Geology problems of the South Urals and Volga the southern Cis-Urals are at present provided Region, Saratov University Publication, 8th issue: with reasonably complete paléontologie descrip­ 1-16 [in Russian]. tion. Their detailed division was carried out Kochetkova N. M. 1970. — Stratigraphy and ostra­ codes of the Upper Permian beds from the southern according to ostracode fauna. The red beds of regions of Bashkiria and the adjacent areas of Oren­ the Ufimian stage are characterized by a non- burg region. Nedra, Moscow, 118 p. [in Russian]. marine ostracode complex dominated by repre­ Kuleva G. V. 1975. — The Upper Kazanian and sentatives of Paleodarwinula genus. Within the Tatarian continental deposits from the southern part sections with the Kazanian marine and continen­ of Cis-Ural Marginal Deflection (within the Orenburg and south Baskirian Cis-Urals). Saratov tal deposits, the marine-rock sequences are cha­ University Publication, Satatov, 164 p. [in Russian]. racterized by rich marine-ostracode complexes of Molostovsky E. A. & Molostovskaya I. I. 1967. — Healdia, Bairdia, Amphissites, etc., genera. The Stratigraphy of the Upper Kazanian and Lower non-marine Kazanian deposits contain a single Tatarian deposits from the Salmysh zone. Geology complex of non-marine ostracodes, mainly of problems of the South Urals and Volga Region, Saratov Univetsity Publication, 4th issue part 1: Paleodarwinula and Darwinuloides genera. 35-42 [in Russian]. The most detailed stage division by ostracodes Molostovskaya I. I. 1974. — The Lower Tatarian was carried out for the Tatarian, with the ostracodes from the upstteam Samara River basin Urzhum, Notth Dvina and Vyatka horizons and their stratigraphie importance. Geology pro­ clearly distinguished by the ratios of certain spe­ blems of the South Urals and Volga Region, Saratov cies and genera. The Urzhum horizon is defined Univetsity Publication: 53-58 [in Russian]. — 1993. — Non-matine osttacodes and paleobiogeo- by the combination of Paleodarwinula species graphical distribution of the Late Permian basins in and abundant Prasuchonella; the North Dvina the East of Russian Plate. Contribution to Eurasia one by domination of Suchonellina and Geology. Assosional Publications ESRJ New Series, Prasuchanella, the Vyatkian horizon by origina­ University South Caroline No.9B: 95-100. tion of new geneta: Wjatkellina, Dvinella and — in press. — New Late Permian osttacods from the Cis-Ural. Report of Russian Academy of Science. Suchonella. Ochev V. G., Tverdokhlebova G. I., Minikh M. G. & The peculiarities of ostracode complex distribu­ Minikh A. V. 1979. — Sttatigraphic and paleogeo- graphic importance of the Upper Permian and tions revealed in the Cis-Ural Deflection, are sus­ Triassic vertebrates from the East-European tained all over the Russian Plate (Molostovskaya Platform and Cis-Urals. Saratov Universiry 1993) fot detailed correlations within vast terri­ Publication, Saratov, 81 p. [in Russian]. tories from the boteal tegions to the northern Romanov V. V. 1972. — To the stratigraphie subdi­ fringes of the Tethys. vision of the Early Kazanian marine beds from the bordering platform part of the Orenburg Cis-Urals. The presence of peculiar endemic cytherid com­ Geology problems of the South Urals and Volga plex in the south-east of Cis-Ural Marginal Region, Saratov University Publication, 8th issue: Deflection may point to a possible link between 17-30 [in Russian].

Submitted for publication on 15 January 1996; accepted on 1 October 1996.

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