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ISSN 00310301, Paleontological Journal, 2014, Vol. 48, No. 7, pp. 701–849. © Pleiades Publishing, Ltd., 2014.

Fusulinids (Foraminifera), Lithofacies and Biofacies of the Upper Moscovian (Carboniferous) of the Southern Moscow Basin and Oka–Tsna Swell D. V. Baranovaa, P. B. Kabanovb, and A. S. Alekseevc a

University of Calgary, 2500 University Dr., NW Calgary, Alberta, T2N 1N4 Canada email: [email protected] b Geological Survey of Canada, 3303–33rd st., NW Calgary, Alberta, T2L 1A7 Canada c Department of Paleontology, Faculty of Geology, Moscow State University, Moscow, 119991 Russia Borissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997 Russia Received December 20, 2011

Abstract—Twentynine fusulinid species of 14 genera are determined in the Podolskian and Myachkovian substages (Pennsylvanian) of the southern Moscow Basin. All test sections are determined to genus level, except for the genera Schubertella and Fusiella. Since it is impossible to distinguish between these two genera in oblique test sections, they are identified to the family Schubertellidae. The stratigraphic distribution of fusulinid species put on a new sequence–stratigraphic framework (succession of cyclothems) reveals nonsi multaneous appearance of zonal assemblages in different localities. Sporadical occurrence of index species below and above their designated zones attest for shortage of reliable biostratigraphic markers within the Upper Moscovian interval. The legacy acmezones Fusulinella bocki and Fusulina cylindrica appear to be the most robust divisions in the regional fusulinid zonation. The Podolskian–Myachkovian stratigraphic interval is characterized by progressive decline of Neostaffella, whereas representatives of Fusulina show inverse devel opment. The genus Fusulina changes its facies preference from normal marine subtidal facies in the Podol skian to shoal peloidal–bioclastic grainstones in the upper half of the Myachkovian. Fusulinid genera tend to be distributed patchy and within a broad facies range. It is confirmed that the staffellid genera Reitlingerina and Parastaffelloides are good indicators of shallowwater normal marine euphotic conditions. The genus Hemifusuina occasionally masses in muddominated tempestitic limestones of shallowingupward (regres sive) parts of cyclothems. Schubertellids were the most tolerant group as seen from their steady presence in the entire spectrum of marine facies of the studied basin. Five fusulinid biofacies are recognized in the Upper Moscovian: (1) Fusulinella–Ozawainella, (2) Staffellida, (3) Staffellida–Fusulina, (4) impoverished Schuber tellidae, and (5) Hemifusulina. These paleobiofacies are based on mean densities of fusulinids in thin sections (tests per cm2), data departure criteria of these mean densities, the Shannon diversity index H, and Berger Parker index of dominance d. Degree of differentiation of fusulinid biofacies is notably low, which is explained by unsteady benthic environments affected by frequent storm dispersals of benthic organisms and geologically rapid eustatic sea level changes. The relation of fusulinid, conodont, and general biofacies is dis cussed. Three general biofacies are recognized: staffellidsyphonean (photozoan and transitional hetero photozoan), bryonoderm extended (heterozoan), and MeekellaOrtonella (assemblages of stressed shallow lagoon to tidalflat habitats). Keywords: Foraminifera, Fusulinida, Carboniferous, Upper Moscovian, Moscow Basin, Oka–Tsna Swell, zonation, cyclothems, biofacies, lithofacies DOI: 10.1134/S0031030114070016 CONTENTS INTRODUCTION CHAPTER 1. MATERIAL AND METHODS 1.1. Materials 1.2. Microscopic Study 1.3. Data Processing CHAPTER 2. STRATIGRAPHY, LITHOFACIES, CYCLICITY, AND SEDIMENTARY MODEL 2.1. Stratigraphy 2.2. Lithofacies 2.3. Distribution of Lithofacies in Cyclothems 701

703 704 704 706 711 711 711 714 719

702

BARANOVA et al.

2.4. Duration of the Upper Moscovian and Main Transgressive–Regressive Cycles 2.5. Sedimentary Environments and Basin Functioning CHAPTER 3. SPECIES COMPOSITION AND STRATIGRAPHIC DISTRIBUTION OF FUSULINIDS 3.1. Characteristics of Formations Based on Fusulinids 3.2. Stratigraphic Distribution of Fusulinids CHAPTER 4. FUSULINID BIOFACIES 4.1. Terminology and Approach to Biofacies Recognition 4.2. Facies Distribution of Podolskian Fusulinids 4.3. Facies Distribution of Myachkovian Fusulinids 4.4. Changes in Facies Preferences of Fusulina 4.5. Criteria for Fusulinid Biofacies 4.6. Fusulinella–Ozawainella Biofacies 4.7. Staffellid Biofacies 4.8. Impoverished Schubertellid Biofacies 4.9. Staffellida–Fusulina Biofacies 4.10. Hemifusulina Biofacies 4.11. Biofacies and Sea Level Fluctuations 4.12. Frailty of Fusulinid Biofacies and Data Quality Limitations CHAPTER 5. RELATIONSHIP OF GENERAL, FUSULINID, AND CONODONT BIOFACIES 5.1. Benthic Carbonate Factories and General Carbonate Facies of the Phanerozoic 5.2. Staffellid–Syphonean Biofacies 5.3. Extended Bryonoderm Biofacies 5.4. Meekella–Ortonella Biofacies 5.5. Ooidal “Biofacies” 5.6. Conodont Biofacies 5.7. Relationship of Fusulinid, Conodont, and General Biofacies CHAPTER 6. SYSTEMATIC PALEONTOLOGY CONCLUSIONS ACKNOWLEDGMENTS REFERENCES APPENDICES 1. Data on Facies Distribution of Fusulinids of the Podolskian Substage 2. Data on Facies Distribution of Fusulinids of the Myachkovian Substage

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INTRODUCTION Fusulinids are larger benthic foraminifers with a complex test. Larger benthic foraminifers (LBF) are an informal group including extinct Lituolida and Fusulinida and extant Miliolina and Rotaliina (Haynes, 1981; Loeblich and Tappan, 1984). LBF tests are mostly larger than 1 mm in linear size and usually do not exceed 3 mm3 in volume (Ross, 1974); however, fossil forms reach 500 mm3, for example, Nummulites millecaput (BeavingtonPenney and Racey, 2004). Ecological investigation of presentday LBF is likely giving the ground to interpret the paleo ecology of fusulinids and others extinct LBF. Fusulin ids played an important role in benthic marine com munities of the Pennsylvanian and Permian, although they were restricted to warmwater basins of tropical and subtropical regions (Ross, 1972, 1982). Fusulinids have been used in the Upper Paleozoic biostratigraphy since the 1930s. The biostratigraphic value of fusulin ids is particularly high in core studies where available rock material is usually insufficient to extract con odonts. A significant restriction for biostratigraphic use of fusulinids as well as other benthic groups is their facies dependance and influence of geographical bar riers. Fusulinids of the central part of the East European Craton have been studied since the 19th century (Fis cher de Waldheim, 1829–1830; Moeller, 1877, 1878a, 1978b, 1880), with emphasis on their taxonomy and biostratigraphic use (Schellwien, 1908–1909; Bolkhovitinova, 1937, 1939; Rosovskaya, 1940, 1941, 1946; RauserChernousova et al., 1951; Rauser Chernousova and Reitlinger, 1954; Ivanova and Khvorova, 1955; Sheng, 1958; Chen JinShi, 1963; Solovieva, 1963, 1977, 1984, 1986; Nikitina, 1974; Field Excursion …, 1975; Davydov, 1990; Alekseev et al., 1995; Davydov, 1997, 1999; Villa et al., 1997; Isakova, 1998, 2001, 2002, 2013; Makhlina and Isakova, 2000; Alekseev et al., 2000; Makhlina et al., 2001a; Baranova and Kabanov, 2003; Kabanov et al., 2006; Kabanov and Baranova, 2007; Goreva et al., 2009a, 2009b). A value of foraminifers for correlation in the Car boniferous was recognized for the first time by Rauser Chernousova (1938) in her study of the Samara Bend and Transvolga Region. The presence of two fusulinid zones in the Myachkovian of the Moscow Region was outlined by Bolkhovitinova (1937, 1939) and then cor roborated by Rosovskaya (1940, 1941). The lower zone was characterized by abundant Fusulinella bocki Moeller and rare Fusulina, while the upper zone, which corresponds to the Peski Formation in the sec tions near Myachkovo and in the Pakhra River Basin, has yielded abundant Fusulina. RauserChernousova and Reitlinger (1954) described stratigraphic distribu tion of fusulinids in type sections of the Moscovian Stage located on the southern flank of the Moscow Syneclise. The syneclise is the longused Russian term describing broad and shallow epicratonic basins usu ally filled by epeiricsea deposits. Nikitina (1974) rec PALEONTOLOGICAL JOURNAL

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ognized three fusulinid zones in the Podolskian and two in the Myachkovian in the core from the central Moscow Syneclise. Solovieva (1963, 1977) utilized certain local zones from the Moscow Region as a basis for a general zonal chart of the Moscovian Stage. In later works of Solovieva (1984, 1986; Solovieva et al., 1985) this chart has undergone only little modifica tion. The Myachkovian zones remained unchanged; however, the zonal assemblages received ample char acterization. New data on fusulinid distribution in the Moscovian Stage stratotype area were obtained within the frame of projects focussing on the Moscovian– Kasimovian boundary (Alekseev et al., 1995; Makhlina et al., 2001a, 2001b). Ivanova (1998, 2000) included some fusulinid zonal indexes from the Mos cow Region into the the Upper Moscovian zonal scheme of the Ural Mountains. Konovalova (2000) proposed a zonal scheme for the Moscovian and Kasi movian stages of the Timan–Pechora Basin, which was similar to the zonation in the type stage region. Fusulinid zonation of the southern Moscow Syneclise was tackled in a number of works over the past decade (Isakova, 1998, 2001, 2002; Alekseev et al., 2000; Makhlina and Isakova, 2000). Three zones were rec ognized within the Podolskian (Table 2): Putrella brazhnikovae (Vas’kino Formation), Fusulinella cola nii–Fusulina ulitinensis (Ulitino Formation), and Fusulina chernovi (Shchurovo Formation). Three zones were designed in the Myachkovian: Fusulinella bocki (Korobcheevo Formation and the lower two thirds of the Domodedovo Formation), Fusulina cylindrica (upper onethird of the Domodedovo For mation and lower onethird of the Peski Formation), and Protriticites ovatus (two upper thirds of the Peski Formation). The establishment of the new genus Praeobsoletes and recognition of the new phylogenetic lineage of Fusulinella schwagerinoides–Praeobsoletes–Obsoletes (Remizova, 1993) has stimulated changes in fusulinid zonation of the Myachkovian (Davydov, 1997). Davy dov (2007; Davydov and Nilsson, 1999) summarized that the Protriticites–Montiparus chronocline can be traced across the western Eurasia from Central Asia to Spain and to the Arctics. Davydov et al. (2012) include the Protriticites ovoides–Praeobsoletes burkemensis Zone in the global zonal standard (Pf12 Zone). It should be noted, however, that correlation of Russian and Spanish sections based on fusulinids alone does not provide reliable results (Villa et al., 1997), because Fusulinella developed during that time as two phyloge netic lineages, with only one represented in each region. Revision of the type material of the genus Praeobsoletes Remizova, 1993 corroborated the assumption of Villa and Ginkel (Ginkel and Villa, 1999) that Praeobsoletes should be regarded as a junior synonym of the genus Protriticites (Baranova, 2005). The paleoecology and facies distribution of fusulinids have long been attracting certain interest (Elias, 1937, 1964; Kahler, 1942; RauserChernous ova and Kulik, 1949; Reitlinger, 1950; Rauser

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Chernousova, 1953, 1961a, 1961b; 1975; Rauser Chernousova and Reitlinger, 1954; Luniyak, 1953; Semikhatova, 1954, 1956; Ivanova, 1958, 1973; Kire eva, 1959; Volozhanina, 1960; Cummings, 1961; Lip ina, 1961; Nikitina, 1961; Ross, 1961, 1965b, 1967b, 1968, 1969b, 1971, 1972, 1982; Henbest, 1963; McCrone, 1964; Thompson, 1964; Fomina, 1966, 1969; Kirsanov, 1966, 1970; Stevens, 1966, 1969, 1971; Rich, 1969; Skipp, 1969; Toomey, 1969; Mamet, 1970, 1977; Alekseeva and Kashik, 1973; Solovieva and Vishnevsky, 1973; Toomey and Win land, 1973; Chuvashov, 1975; Dzhenchuraeva, 1975; Gibshman, 1975; Konovalova, 1975; Potievskaya, 1975; Wilson, 1975; Toomey et al., 1977; Brenckle et al., 1987; Dingle et al., 1993; Lees, 1997; Villa and Bahamonde, 2001; Wahlman, 2002; Wahlman and Konovalova, 2002; Baranova and Kabanov, 2003; Gal lagher and Sommerville, 2003; Della Porta et al., 2005; Kabanov and Baranova, 2007; Filimonova, 2010). Up to the 1950s, fusulinids were considered to be inhabitants of epicontinental seas. Subsequently, it was shown that they also inhabited tidal flats and oce anic shelves (Kahler, 1955; Dunbar, 1957; Rauser Chernousova, 1960; Thompson, 1967). It is believed that the lower bathymetric boundary of the fusulinid range was probably the same as for the extant tropical symbiontbearing LBF, that is, limited to the depth of the photic zone (Ross, 1972; Lee and Hallock, 1987). However, no direct indications of obligatory or facultative symbiotic algae are yet found in fusulinids (Leutenneger, 1984; Mikhalevich, 2000; BeavingtonPenney and Racey, 2004). The upper boundary of the fusulinid depth range is determined by transition to stressed coastal or bank facies (lagoons, tidal flats, oolite sandbars). In these restricted onshore facies, the abundance and diversity of fusulinids rap idly drops in favor of small and eurybiontic forms (Luniyak, 1953; Ross, 1972, 1982; Potievskaya, 1975; RauserChernousova, 1975; Della Porta et al., 2005). The morphology of fusulinid tests does not show a dis tinct facies dependence that could be traced from basin to basin. It is only possible to demonstrate that forms with a certain morphology in a particular basin or part of a basin preferred certain conditions (Kire eva, 1959; Potievskaya, 1975; Della Porta et al., 2005). However, even species of the same genus having minor morphological differences can have different facies distribution at the same stratigraphic level (Ross, 1969). At the same time, members of different genera

at different stratigraphic levels can show identical facies preferences. In addition, facies preferences depend on the evolutionary stage of a particular spe cies or genus, i.e., whether the group is closer to the initial expansion or extinction (RauserChernousova and Kulik, 1949). Luniyak (1953) admitted the grada tional nature of fusulinid biofacies and lack of distinct pattern in distribution of fusulinid assemblages within “sedimentary rhythms” (probably implying cyclothems). Since the work of RauserChernousova and Kulik (1949), staffellids were distinguished from other fusulinids and assigned to a special paleoecological group associated with the shallowwater facies. Such facies sometimes lack or contain few other fusulinids. In our material, staffellids are represented by the gen era Parastaffelloides and Reitlingerina (Rauser Chernousova et al., 1996). This facies preference of staffellids has been shown for the East European Cra ton (RauserChernousova et al., 1951, 1996; Rauser Chernousova and Reitlinger, 1954; Kireeva, 1959; Potievskaya, 1975; RauserChernousova, 1975; Bara nova and Kabanov, 2003), North America (Rich, 1969; Dingle et al., 1993), and the Asturian Basin (Della Porta et al., 2005). However, none of the above cited works deal with quantitative assessment of all fusulinid tests in thin sections. Only the number of tests identified to species level (hence only axial test sections) and the ratios of species and genera, genera and samples, genera and thin sections were usually reported. The main goal of the present study is a quan titative assessment of fusulinid distribution across the lithofacies spectrum by calculation of all test sections. Placing our data on a new system of lithofacies and sequence stratigraphy (Kabanov, 2003; Kabanov and Baranova, 2007) is expected to provide most substan tial and relatively nonbiased resolution to facies and stratigraphic distribution of fusulinids. CHAPTER 1. MATERIAL AND METHODS 1.1. Materials This study is based on field and lab materials obtained from 1996 to 2007. Thin sections for micro facies and fusulinid study come from nine quarry pit sections and one core of the southern Moscow Synec lise (Fig. 1: Domodedovo, composite Peski section, Podolsk, Priokskii, Afanasievo, and Gory) and Oka– Tsna Swell (Akishino, Maleevo, and Kasimovskii). In

Fig. 1. Paleogeography of the East European Craton during the Moscovian Age and location of studied sections: (a) global paleo geographical reconstruction for the Moscovian (306 Ma) (www.scotese.com, with simplifications and minor modifications); dot ted line contours the Moscow Basin. (b) East European Craton during Moscovian (Nikishin et al., 1996, modified): (1) mostly shallowwater carbonates; (2) relatively deepwater carbonates, shales, and siliceous shales; (3) basins with oceanic crust; (4) car bonates with organogenic buildups; (5) shallowmarine carbonates and shales; (6) shallowmarine sands and shales; (7) conti nental sands; (8) land; (9) active orogenic belts; (10) continental slopes; (11) subduction zones; (12) modern erosion limit of the Moscovian Stage; (13) natural outcrops; (14) position of sections (c) southern Moscow Syneclise; and (d) Oka–Tsna Swell): (1) Podolskian cement factory (PD), (2) Domodedovo (D), (3) Afanasievo (AF), (4) Starye Peski (OP), (5) Konev Bor (KB), (6) Priokskii (PRI), (7) Markovo (MAR), (8) Gory (GOR), (9) Akishino (quarry and borehole), (AK), (10) Maleevo (MA), and (11) Kasimovskii quarry (KS). PALEONTOLOGICAL JOURNAL

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705

(a) 60° N Angaraland

30° N Euramerica

Panthalassa Ocean

(Laurussia)



Paleotethys

30° S

Gondwanaland

60° S Gondwanan iceshield Shelfal and epeiric seas

Subduction belt

Oceanic and paraoceanic basins

Land

AppalachianAtlasian Cordillera

(b) (d)

Mo

Sy

w sco

n

Oka Rive r

e n se e z cli M yne S

Fenno scandian Shield

i ecl

9

Kasimov

10

11

50 km

se

1

C

2 3 4 5 Moscow

Zvenigorod

Mozhaisk

2

Pakhra River 1

NaroFominsk

Podolsk

(c) 6

Lyubertsy M os kv aR ive r

Domodedovo

7 8 Voskresensk

3

4

10

5

11

Kolomna

6

7

9

13

Oka River

0 km

50

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Ozery

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8

14

706

BARANOVA et al.

Table 1. Thinsection materials included in numerical analysis Formation under study

Section

Number of thin sections

Total area of thin sections, cm2

46

666

Gory quarry (GOR)

Vas’kino

Priokskii quarry (PRI)

Gory–Korobcheevo

104

1594.85

Maleevo quarry (MA)

Gory–Korobcheevo

69

1059.5

Akishino borehole (AKF3)

Akatievo–Korobcheevo

43

517

Akishino quarry (AK)

Korobcheevo–Peski

79

976.55

Podolsk quarry (PD)

Gory–Korobcheevo

77

1125.25

87

968.25

Peski quarry: Konev Bor (KB) Korobcheevo–Peski and Starye Peski (OP) (only data from Korobcheevo and Domodedovo formations where test counting was performed) Domodedovo quarry (D)

Shchurovo–Peski

Kasimovskii quarry (KS)

Akishino–Peski

33

599.25

Afanasievo quarry (AF)

Peski

33

355.25

Total number of sections: 9

Entire range from Vas’kino to Peski formations

addition, we studied fusulinids from the Markovo quarry (Moscow Syneclise) and Pinega mapping area of the Arkhangelsk Region (Mezen Syneclise), although these data are only used for taxonomic pur poses without numerical assesment. In addition, thin section collections of A.S. Alekseev (Moscow State University: MGU), M.N. Solovieva (Geological Institute, Russian Academy of Sciences: GIN), S.E. Rosovskaya (Borissiak Paleontological Institute, Russian Academy of Sciences: PIN), D.M. Rauser Chernousova et al. (GIN), G.A. Dutkevich (Cherny shev Central Research Geological Museum, St. Petersburg: TsNIGR Museum), and P.P. Voloz hanina (Central Research Laboratory of the Ukhta Industrial Complex, Ukhta: TsNIL) were used to clar ify taxonomic and stratigraphic questions. Unpub lished materials of T.N. Isakova and report of P.P. Volozhanina were involved. The study of fusulinid distribution was part of a sequence of projects supported by the Russian Foun dation for Basic Research on facies distribution of fos sils and biotic responses to sea level fluctuations in the Pennsylvaniantime epeiric basin of the East Euro pean Craton. In addition to fusulinids, these thin sec tions were also used for quantitative assessment of cal careous algae and robust semiquantitative inventory of other allochem types (Kabanov et al., 2006; Kabanov and Baranova, 2007). The distribution of conodonts was studied using a standard technique for dissolution, with calculation of the conodont number. The most comprehensive data were obtained from the Domode

116

2023

Total number of thin sections: 687

Total area: 9884.9 cm2

dovo cyclothem of the Peski locality, where all macro faunal remains of 5 mm and larger size were counted at the superspecific level in crushed 25kg samples (Kabanov et al., 2006). Subsequently, a similar study was performed for the Domodedovo cyclothem of the Domodedovo and Akishino sections. Macrofaunal fossils were examined in 43 samples from three sec tions. Conclusions on facies distribution of conodonts have been drawn from extensive dataset collected so far from differentMoscovian and Kasimovian sections. Sampling density in nine studied sections are shown in Figs. 2–4. 1.2. Microscopic Study Fusulinids were studied in large (9–36 cm2), verti cally oriented lithologic thin sections sampled in stratigraphic sequence. Serial horizontally oriented thin sections have been made from selected samples to study species composition of fusulinid assemblages. A total of 687 thin sections with the total area of 9884.9 cm2) has been examined (Table 1). Fusulinid tests were counted using 5 × 5 mm grid printed on an overhead film. The film was attached to the thin sec tion by glycerol producing enough capillary force to prevent film movement. Each cell in this grid was numbered allowing rows and columns be followed when counting tests. Thin sections were examined in transmitted light under the Axiolab Pol Carl Zeiss microscope (with EPl 10×/20 oculars and Plan NEOFLUAR 2.5× and Epiplan 10× objectives). PALEONTOLOGICAL JOURNAL

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Bedded Unevenly bedded Lenticular and nodular Cherts Calcareous pebbles Macroscopic vugs and dissolution channels Coarsegrained peloid– crinoid–foraminiferal grainstones Phylloid–algal biostromes a Erosional surfaces: b (a) planar, (b) scalloped Multidirectional cross lamination

KB11a2 KB10a3 KB10a2 KB10a1 KB9cnod, KB9kr KB7kr, KB8/9a, KB9b KB6bkr, KB6kr KB5/6, KB6a KB5c2 KB5b/c KB5b1 KB5a/b KB5a1 KB43

Nikit. + Rozh.

7–9 6 c 5b a 4

KB42 KB41 KB2b3 KB2b2 KB2b1 KB2a KB1c1 KB1a/c KB1a

2 1

7

GDR27a/b

6

GDR26b2 GDR26b1 GDR25/6 GDR257 GDR256 GDR255, 5b3 GDR254 GDR252 GDR251

5a

Formation Member Bed no.

Oz1

Ap

GDR24b2 GDR24a2 GDR24a1

3b 3a

32

30 29 28 27 26 25 24

23c

PRI302 PRI301 PRI28/29 PRI27n, 27, 27b PRI262, 263, 264 PRI26n PRI25, 252 PRI251 PRI241, 242, 24/25 PRI23/24 PRI23bcb2 PRI23c6 PRI23c5a, 23c5b PRI23c4 PRI23c3

23b 23a 22

17 16 15 14 12

11

10 9 8 7

GDR233, 34 GDR232 GDR231 GDR22 GDR22nog GDR21

PRI33n, 33, 33b PRI32ckr

PRI31/32

SC

6 5 4 3

PRI23c2 PRI23c1 PRI23b3 PRI23b1, b2 PRI23a/b PRI23a2 PRI23a1 PRI22/23 PRI224 PRI223 PRI221, 222 PRI22n PRI202 PRI201, 718 PRI182, 718 PRI18a, 181 PRI17/18 PRI174 PRI173 PRI172 PRI171 PRI162 PRI161 PRI15, 15 vein PRI143 PRI142 PRI141 PRI12kp2, 12kp PRI121 PRI121 PRI114 PRI113 PRI112 PRI911b PRI111 PRI102 PRI101 PRI9/10 PRI93 PRI92 PRI91 PRI82 PRI81 PRI7/8 PRI73 PRI72 PRI71 PRI62, 63 PRI5 PRI43 PRI42 PRI41 PRI3/4 PRI31 PRI31 PRI2b3 PRI2b2 PRI2b1 PRI92a3

2 Vas’k.

2

35

31

GDR25a

4

Priokskii (PRI)

3334

? 20 19 18

Oz2

8a

5b

Domod. Nikitskoe + Rozhaika Pan’sh.

Db2 Db1

Gory (GOR), lower part of section

5c

Korobcheevo

11

Yu

Korobcheevo

Bedding:

OP4a2 KB131 KB12kr, KB12/13 OP13/4 OP13bn KB12a/b KB11bkr OP12b1, OP2/3 KB11a3 OP12a

12

Gory Formation Member Bed no.

Marine shales and marls Clayey horizons of paleosols Dolomitic lenses

13

Up.Gorod.Kamenka

Dolomitic limestone

OP9b1, 92 OP19a, OP29a1 OP6b3, OP16 (up) OP6b1, OP6b2 OP6a3, OP6a/b OP4b2, OP4b3, OP4b4 OP4a4

10

Vas’kino

Pure Weakly argillaceous Argillaceous

Limestone

Legend

21 20 19 18 16 15 b 14 a

Shchurovo

2

Storm graded beds Names of subaerial disconformities: Ac = Achkasovo KB = Konev Bor Yu = Yusupovo Db = Dubrovitsy Oz = Ozery Ap = Apraksino SC = Sennitsa Creek

OP1192 KB231,2 SP13kr, OP118c2 OP118b2 OP118a5, 18a7 OP118a3, 4 OP118 NP25 OP117c1 OP117b1, OP117b2 OP117a1, OP117a2 OP116d, OP116a2 OP116b1,2, OP116c OP115, OP152OP36f, OP116a OP114a, OP114b OP113a, 13b, 13c OP112e OP111a1, 11b OP110b OP10a1,2

Kuzne Staryi Yam chiki?

Domodedovo

AF5a/b

4

OP201,2,4

22

KB

Gubastovo

AF5r2, 5g/d

Pan’shino

5b 5a

0

KB26/27 KB25/26 KB25a3

26 25 24 23

Lemeshevo

AF5d3, 4 AF5d1, 2

KB27

27

Akatievo

5c

28

Erino

AF73, 4 AF71 AF56a, 6n AF5/6n AF5d5, 6, 7

KB28

Staraya Ruza

8 7 6

2m

KB29a/b

29 a

Ign.

9

KB302

30

Markovo

AF111, 112, 113 AF110a, 10 AF9kr AF93 AF92 AF9n AF82, 8/9

11 10

31

Upper

Peski

12

Lower Gorodnya

Domoded. Peski Gubastovo Kamennaya Tyazhina Lower Titovo Up.TitovoVolodarsky

AF1122

Babur.Low.

Ac

14a

Gory

14c

707

Composite Peski section (OP + KB)

Kamenka

16 15

Kam. Tyazh. Lower Titovo Up.Titovo

Formation Member Bed no.

Afanas’evo (AF), lower part of section

Staryi Yam

Suvorovo Formation Member Bed no.

FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES

PRI92a1

1

PRI92n PRI1bp, PRI1b1

PRI1a

Fig. 2. Correlation and sampling points of Afanasievo, Peski, Priokskii, and Gory sections. PALEONTOLOGICAL JOURNAL

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No. 7

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8

4 3b

3a 2c 2b 2a 1

– AK315c3 – AK315c2 Lash. – AK315c1– /Via – AK315b5–AK315c2n2, 15c2kon Vib – AK315b4 –AK315b2, 15b3 – ––AK315a, 15b1 – AK3143, 144 – – – AK3141, 142 Vic – – AK3131, 132 – AK3124 – AK3122, 123 – – AK3121 – – AK3111, AK1112, 113 – – – AK310c2, AK710c5, AK310c3, AK110kr –AK310c1, AK710b4 – – AK710c3 Vid – AK710c1, AK710c2 – – AK710b/10c – – AK710b1 10b2 – –AK710a/b AK68kr VII –AK682 Yu2

Yu1 AK65/6, AK56, AK6a – –AK62, 63 – – AK6n – – –AK4b2, AK4bkr, AK4/6u –AK4a – –AK23/4, 41 – AK33kr –AK33 – –AK31 –AK53akr, 3b1 –AK53a3

VIII

Formation Bed no.

Tashenka Peski

e 30 с

KS302, 303, 304

KS301 KS30n KS292 KS28/29, KS291 KS27kr, KS28 KS26/27, KS271 KS262 KS261

a

29

Akishino (borehole F3)

26

Kb2

–AK52a1 – – AK51n4, 1n5 – – AK51n2, 1n3 X

Maleevo

33 MA2323

32

MA2316 MA2314 MA2312

31 30

MA230a/b MA230a1

28

MA228a2 MA227c3 MA227c2 MA227b1 MA227a

27

25 Kb1

24 KS236, KS237 KS234, KS235 KS232, KS233 KS231

23

–F320,4

–F322,2 –F322,6 –F323,0 – –F323,2, F323,3 – F323,9 – –F323,7, –F324,2, F324,0 F324,45 – –F324,6 –F325,0 –F325,25 – –F325,8, F325,6 –F326,0 –F326,2 – –F326,45, F326,55 –F326,7

–F329,4 –F329,75 –F330,0 –F330,4 –F330,7 –F330,85 – –F331,3 F331,2 – –F331,55 F331,7 –F332,1 –F332,4 –F332,9 – –F333,35, F333,2 –F333,5 – –F333,8 F334,0

26 MA226n MA1243 MA1241

22 MA120b2

20

MA1191 MA118a3

18

17

MA117a4 MA117a1

Db2? ?

?

MA216bkr, MA116c

16 15

MA115kr MA115a2 MA114b2

14

Db2?

MA313c MA313bkr, 13b/c MA313b MA313a

13

IX

–AK52c1 –AK52b3 –AK52b1, 2b2 –

Korobcheevo

– AK315c4

Pan’sh.

Domod. Formation

– AK3193 – – AK3191, 192 – AK1181, 182 – – AK1165, 166 – – AK3163, 64 – AK3162 – AK3161 – AK115/16 – AK315c5

Member/unit

– AK1222 – AK1213 – AK1212

7

Lash ma 6

32

Shchurovo

10

34

Akatievo

14 13 12 11

KS353 KS351, KS352 KS343 KS342 KS341 KS331, KS332 KS32kr KS324 KS323 KS322 KS321 KS311, KS312 KS30v KS305

35

MA2125 MA2123 MA211b2 MA211b1 MA211a1 MA211a2 MA19/11

12

11

Oz

MA193 MA192 MA19a, 91 MA183

9 8

Markovo

15a

c 38 b b a 37

MA182 MA181

7

MA172 MA171 MA16a

5

MA14c3

–F335,2

1m Shchurovo

XI

MA14b4, 4b5 MA14b2, 4b3 MA14b1 MA13c2 MA13c1 MA13b, 3b/c MA13a3 MA12c, 2kr, 3a1 MA12b MA11c7 MA11c4 MA11c3 MA11c1 MA11a

4 3

Ap XII

–F337,9

Gory

15b

– AK1271 – AK1261 – AK124/25

Akatie vo

Gubastovo

Domodedovo

15c

– AK1272

Korobcheevo

21

16

Pan’shino

Suvorovo

Formation Member Bed no. Peski

Kam. Tyazh.Up. + Low. Titovo Volodarsky

Ac1

Akish. 18

Korobcheevo

Ac2

28

26 25 24

Kasimov quarry (Peski–Suvorovo interval)

40

Akishino (quarry)

29

27

Bed no.

BARANOVA et al. Formation

708

2 1

Fig. 3. Correlation and sampling points of Akishino (quarry and borehole F3), Kasimovskii quarry, and Maleevo sections; see Fig. 2 for legend. PALEONTOLOGICAL JOURNAL

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Formation Member Bed no.

FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES Domodedovo (D)

43

41

Kam.Tyazhino Lower Titovo Up.Titovo Volod.

Dom. Formation Member Bed no. 41

Peski

38

30 28

Gubastovo

PD322 PD31b2, 31bkr, 31b/32 PD31bpod, 31b PD31a PD3306 PD3305 PD3304 PD3303 PD3302 PD3301 PD292 PD29/30 PD291 PD287 PD284 PD281 PD28p PD26kr

Domodedovo

31

26

23

PD182 PD181 PD174 PD173 PD172

15

PD16 PD155, 15kr PD154 PD153 PD152 PD151, 15b PD14kr PD14b

14

PD143

13 12

PD142 PD13/14, 141 PD132 PD131 PD114 PD113

11 PD11pod

10 9 8 6 4 3 1

PALEONTOLOGICAL JOURNAL

35a

34 33 32

PD94 PD93 PD92 PD91 PD8/9 PD83 PD82 PD81 PD7

Vol. 48

D352 D34/35, 351 D335, 33c, 33/34a D334, 33b D32/33, 331, 332 D32c D326 D325 D32b

23, 24

21

D21

28 c

27 b

a

26

18

D202

D18 D17/18 D17b D17a

16 15

13 12 11 10 9d 9c 9b 9a 8e 8c, d

8b 8a

D15

6

5a, b 3 1

2m

No. 7

D13a2 D13a1 D12/13 D122 D121 D11/12 D11 D9/10 D1d1 D9c D9bkr D9a/b D8/9 D8e1 D8d2 D8c3 D8b/c, 8c1 D8b5 D8b4 D8b1 D8a4 D8a3 D471, 2, 3, 4

PD5 PD4kr PD42 PD41 PD3/4 PD32 PD31 PD2a2 PD1kr PD1

D353

D321, 32a1 D317 D316 D314, 315 D313 D311, 312 D292 D283, 28kr D281 D27c2 D27c1 D27bkr D27a3, 27a/b D27a1 D26b1 D25/26 D25 D24/25 D241

31 30

5d 5c

Kuznechiki

Akatievo

17

PD20/21 PD203 PD202 PD201 PD193 PD192 PD18kr

Korobcheevo

19 18

GoryMarkovo

PD24niz PD233 PD232 PD231

21 20

35b

14

Shchur.

Shchurovo

24

PD25

35c

D37c2 D374 D372 D371 D364 D362 D35/36, 36a(low), 362 D3512 D3511 D3510 D359 D358 D356, 357, D35b D355 D354

D201

Nikitskoe Rozhaiskaya

25

37 36a, b

20

Pan’shino

33

Staryi Yam

34

Thin sections

Korobcheevo

36

39

2014

D6pod D5d/6 D5/6, D5d/e D5d2 D5d1 D5c1 D5b/c D5b2 D5b2 D5b1 D5a4 D5a3 D5a1, 2 D34 D33 D32 D31 D1/2, D2, 2/3 D11

Fig. 4. Correlation and sampling points of Podolsk and Domodedovo sections; see Fig. 2 for legend.

42a

Turaevo

Podolsk cement plant (PD)

Thin sections

Suvorovo

42c

709

710

BARANOVA et al.

Fusulinids were counted at the genus level, since it is impossible to determine species in the majority of ran dom sections. Two main approaches in quantification of microfa cies constituents exist. (1) Area analysis exemplified by a popular method of point counting and software recognition of petrographic images. (2) Calculation of the number of particles or grains. The first approach is best applied to components of complex shape (cements, complex biohermal skeletons, etc.) and where components are disparate in size (Flügel, 2004). Calculation using grain number analysis is suitable for grains of 0.063–2.00 mm in size and frequently used in microfacies analysis because of its simplicity. The width of a thin section must be at least ten times greater than the average diameter of grains (Flügel, 2004). Several modifications of counting have been proposed, depending on the character of thin sections and counting equipment (Orel, 1970; Filimonova, 2004). In the material under study, 15 genera have been identified. In nonaxial sections, the genera were diag nosed based on the following criteria. Eostaffella is the smallest form, with a dark, nondif ferentiated wall. Schubertella and Fusiella are mostly small forms with straight septa. These two genera are impossible to distinguish in sagittal and tangential sec tions and, hence, included in the group Schubertel lidae. Ozawainella is subrhombic or round, with rib bonlike chomata and crescent septa. Neostaffella is always close in section to a square. Taitzehoella is bilat erally symmetric, with regular semicircular chomata, straight septa, and a threelayered wall without a diaphanotheca; this is the only genus of Profusulinel lidae known in the Podolskian–Myachkovian. Fusulinella is represented by large sections with wavy septa and a thick wall with diaphanotheca. Fusulinel las lack distinct pores. Fusulina is also a large form with more numerous septa, perforated wall, and poorly differentiated layers. They usually lack chomata, but sometimes possess dense axial deposits. Beedeina is similar to Fusulina, but different in the subrhombic outlines in axial sections. Putrella is one of the largest forms with a high and strong plication and thick twolayer wall with distinct dichotomizing pores. Quasifusulinoides is the largest form with a strong pli cation. Hemifusulina features strong bilateral symme try and distinctly porous wall with the thickest pores among Upper Moscovian genera. Parastaffelloides and Reitlingerina are reliably identified based on recrystal lized wall with a luminotheca. Mature Parastaffelloides are generally larger than Reitlingerina and show nauti loidal volution. The genus Quasifusulinoides is excluded from dataset analysis, because it appears only in the upper part of the Myachkovian Substage and contribute little to Myachkovian biofacies associations.

Collections of thin sections under study are housed in the Department of Scientific Organization of Funds of the Borissiak Paleontological Institute of the Rus sian Academy of Sciences (ONOF PIN), collection nos. 5039, 5040, 5041, 5042, 5045, 5046, 5047, 5048, 5058, 5060, 5062, and 5064 (collected by P.B. Kabanov and D.V. Baranova); in the Laboratory of Micropaleontology of the Geological Institute of the Russian Academy of Sciences, no. 4793, (col lected by T.N. Isakova) and no. 3287 (collected by D.M. RauserChernousova); in the JSC “Timan– Pechora Research Center” (TPNITs2), Ukhta, Komi Republic (collected by P.P. Volozhanina for work per formed in 1962). The list of thin sections figured in Plates 1–31 is given below: PIN, nos. 5039/1, 5039/KS234, 5039/KS236, 5039/KS262, 5039/KS271, 5039/KS291, 5039/KS2312, 5039/KS322, 5039/KS2341, 5039/KS2351, 5040/AK51p2, 5040/AK51p3, 5040/AK682, 5040/AK1113, 5040/AK3123, 5040/AK3142, 5040/AK315b2, 5040/AK315b3, 5040/AK315c2, 5040/AK1191, 5040/AK1192, 5040/AK1272, 5040/AKF320,4, 5040/AKF322,2, 5040/AKF323,0, 5040/AKF323,7, 5040/AKF3 24,0, 5040/AKF325,25, 5040/AKF325,8, 5040/AK F326,45, 5040/AKF326,7, 5040/AKF329,4, 5040/AKF329,75, 5040/AKF333,5, 5041/MA1 3b/c, 5040/MA13c1, 5041/MA14b5, 5041/MA1 6a, 5041/MA172, 5041/MA313b, 5041/MA116c, 5041/MA117a1, 5041/MA120b2, 5041/MA308, MA230a/b; 5042/PD1, 5042/PD2a21, 5042/PD142, 5042/PD14 kr, 5042/PD183, 5042/PD15krn, 5042/PD3'302, 5042/PD3'303, 5042/PD3'304, 5042/PD3'305, 5042/PD31b1, 5042/PD3'31b2, 5042/PD31bkr, 5042/PD 31b/32, 5042/PD31b/322, 5042/PD344, 5042/PD2'361, 5042/PD2'371, 5042/PD2'382; 5045/PRI141, 5045/PRI12222, 5045/PRI12223, 5045/PRI1223a2, 5045/PRI6253, 5045/PRI926 42; 5046/PS117132, 5047/ORZ6f, 5060/AF5d1, 5060/AF5d4, 5060/AF5d5, 5060/AF5d6, 5060/AF5g2, 5060/AF171, 5060/AF111, 5060/AF110a; 5062/GOR22n1, 5062/GOR22n3, 5062/GOR22n4, 5062/GOR22p5, 5062/GOR231, 5062/GOR2324, 5062/GOR2325, 5062/GOR2 327, 5062/GOR2329, 5062/GOR23211, 5062/GOR252, 5062/GOR254, 5062/GOR25p, 5062/GOR25b3, 5062/MAR301, 5062/MAR303; 5064/D13a1, 5064/D331, 5064/D33b3, 5064/D 36a niz1, and 5064/D415; GIN, nos. 4793/1, 4793/2, GIN, 4793/3, 4793/4, 4793/5, 4793/6, 4793/7, 4793/8, 4793/9, 4793/10, 4793/11, 4793/12, 4793/13, 4793/14, 4793/15, 4793/16, 4793/17, 4793/18, 3287/100, 3287/101, 3287/116, 3287/117, 3287/295, 3287/296, and 3287/399; TPNITs2, nos. 614, 616, 617, 620, 622, 624, and 641. PALEONTOLOGICAL JOURNAL

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES

1.3. Data Processing The following parameters have been used in data analysis. Fusulinid density is the number of test sec tions per 1 cm2 of a thin section. The confidence inter val and steadiness are two parameters characterizing spread in presence/absence and abundance of a taxon in a lithofacies. The confidence interval δ can be –1

expressed as follows: δ = ± t c D st ( n ) , where tc is the upper critical value of the tdistribution (normalized departure from the true mean) with n – 1 degrees of freedom and 95% confidence level, Dst is the standard square deviation for a given sample set (also known as the standard error), and n is the statistical sample size (number of samples/thin sections in our case). The confidence interval notation of data spread is advanta geous over the standart square deviation by taking into account the sample size, which varies greatly in differ ent lithofacies groups. Steadiness s = xavg/Dst, where xavg is the average genus density in a lithofacies and Dst is standard square deviation. Steadiness is conve nient because it falls below 1 when the taxon is either missing in some thin sections or its abundance varies sharply in a thinsection set from one lithofacies. In other words, s < 1 means irregular or unsteady presence of a taxon in a sample set, whereas s > 1 points to per sistence of a taxon in a sample set. The biodiversity is usually described in terms of richness (the number of taxa of the same rank) and evenness–domination. The latter describes the quanti tative ratio of individuals in the groups of the same rank. In biological studies, such groups are mostly populations of species (Magurran, 2004). However, this study deals with genera given the limitations in species identification explained above. The diversity indices are parameters connecting the richness and evenness–domination. From a choise of diversity indices used in biology (Magurran, 2004) and micro paleontology (Baldi and Hohenegger, 2008), we employ the Shannon diversity index and Berger– Parker domination index. Shannon index H: n

H = –

ρi

ρi

∑ ⎛⎝ ρ⎞⎠ ln ⎛⎝ ρ⎞⎠ ,

i=1

where ρi is the number of test sections of a fusulinid genus, ρ is the total number of fusulinids per 1 cm2 of each thin section, and n is the number of thin sections. The Shannon index reaches maximum if many taxa are present but represented by approximately equal number of individuals. The index equals zero if only one taxon is present. Berger–Parker index d: d = ρmax/ρ, where ρmax is the number of the most abundant group (genus) per 1 cm2 of a thin section. Despite its simplic PALEONTOLOGICAL JOURNAL

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711

ity, the Berger–Parker index is frequently considered as one of the best domination proxies, and its recipro cal 1/d is sometimes used as a diversity index (Magur ran, 2004). We also performed several runs of Qmode cluster ization of the Podolskian and Myachkovian datasets (Appendix 1) using STATISTICA 6.0 software. The most consistent results were obtained by clustering fusulinid assemblages of individual thin sections against lithofacies with complete linkage or farthest neighbor method. CHAPTER 2. STRATIGRAPHY, LITHOFACIES, CYCLICITY, AND SEDIMENTARY MODEL 2.1. Stratigraphy The Podolskian and Myachkovian regional sub stages making the upper part of the Moscovian Stage were assigned to the Upper Moscovian Substage in the unified scheme of 1962 (MiklukhoMaklay, 1956; Makhlina et al., 2001a). Originally called horizons, the Vereyan, Kashirian, Podolskian, and Myachkovian stratigraphic packages have been trastferred into regional substage status a decade ago (Makhlina et al., 2001a). For convenience, here we revive the usage of the Upper Moscovian package for the Podolskian– Myachkovian stratigraphic interval. In the present study, we use the sequence strati graphic scheme developed by P.B. Kabanov based on recognition of regional subaerial disconformities (par allel unconformities) maximum flooding horizons, and succession of transgressive–regressive units (cyclothems or sequences; Fig. 5; Kabanov, 2003; Kabanov and Baranova, 2007). The cyclothemic divi sions in the Podolskian (Fig. 5) have not been officially adopted by the Interdepartmental Stratigraphic Com mission of Russia (RMSK) in the formation status. However, here we call them formations for the sake of compatibility with two upper Myachkovian cyclothems that do have formation status (Makhlina et al., 2001a) and the World tendency to recognize cyclothems as principal traceable units in shallow marine Late Paleozoic successions. Table 2 compares our chart with the official formation chart (Makhlina et al., 2001a). According to Kabanov’s correlation of the Peski sections, the thickness of the Domodedovo Formation is greater than that assigned by Makhlina et al. (2001a) and the Podolskian Substage is not exposed in Peski at all. In the previous charts (Ivanova and Khvorova, 1955; Makhlina et al., 2001a), the Shchurovo Formation spans the transgressive part of the Shchurovo–Korobcheevo cyclothem in Podolsk and onehalf of a cyclothem in the Shchurovo and Pri okskii sections. Makhlina et al. (2001a) placed the top of the Vas’kino Formation at the paleosolmarked dis conformity in top of Gory cyclothem in the quarry of

PALEONTOLOGICAL JOURNAL

Vol. 48

Formation

Stage Substage

Kasimovian Krevyakinian Suvorovo (sv)

Marko vo (mr)

Moscovian Podolsian Myachkovian Akatie Shchuro Korobcheevo Domode Peski Gory (gr) vo (ak) vo (sh) (kr) dovo (dm) (ps)

Land

Sea

vs1

vs2

vs3

gr1

ak3 ak2 ak1 mr2 mr1 gr2

sh1

sh2

sh/kr

kr1

kr2

kr3

dm1

dm2

ps2 ps1

sv3 sv2 sv1 ps3

Member

SR

G

Upper reaches of Moskva River

No. 7

Coarsegrained peloid–skeletal grainstones (C1)

Ooidal grainstones (C2)

Shallow normal marine subtidal facies (BD, D1, D2, D3, D4, partly D7) Distal tempestites, Zoophycos wackestones, and calcimudstones (D5, D6, D7) Aeolian grainstones (A2)

Vas’kino (vs)

Relative sea level fluctuation

?

SC

T

Boundary of Podolskian and Myachkovian substages

Rudimentary (immature)

Relatively mature

Ap

Oz

OP KB

AF (lower part)

KOR

AKT

Algal biostromes Pure limestones Argillaceous limestones Marls and interbedding clays, limestones, and marls Clays Argillaceous dolomites and dolomitic marls Dolomites

PRI

MAR

Voskresensk, Ozery, and Kolomna districts

Lithology of sections

?

Db

KB

Ac

Rt

Moscow Region

Lagoonal calcimudstones and intertidal grainstones (В1, В2)

DE LEM

Yu

PD

NI

D

Pakhra River Basin

Profiles of subaerial exposition

?

?

?

?

? MA

0

10 m

?

Silicic nodules

Indices of subaerial diastemata GOR Indices of sections Subaerial changes in tops of cyclothems Erosive surfaces SCD

GOR

AK

KS

Kasimov District of Ryazan Region

712 BARANOVA et al.

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES

713

Table 2. Comparison of stratigraphic schemes for the upper part of the Moscovian Stage proposed by Makhlina et al. (2001a) and Kabanov (Kabanov, 2003; Kabanov and Baranova, 2007). Bold dotted lines in Kabanov’s scheme designate subaerial disconformities; disconformity acronyms are given in bold straight font

Suvorovo

Middle Lower Upper

Novlino

Domodedovo

Lower Upper Korobcheevo Middle

Lower Upper Shchurovo

Middle Lower Upper

Fusulinella colaniae, Fusulina ulitinensis

Hemifusulina, vozhgalica

Turaevo (sv1) Achkasovo Volodarsky (ps3)

Ulitino

Middle Lower

Neognathodus medexultimus– Idiognathodus podolskensis

Upper Vas’kino Lower

Streptogn. concinnus– Idiognathodus robustus

Smedva

Upper

Podolsk cement plant (PD section in Fig. 5). This conclusion is supported by facies pattern, the thick ness ratio, and the sequence of cyclothems in the Pakhra sections (Fig. 5; Kabanov and Baranova, 2007). Five cyclothems are counted from the undisputa ble top of the Myachkovian to the lower disconformity in the PD section. The same number of cyclothems occur

Tashenka (ts)

Peski

Titovskaya (ps2) Kamennaya Tyazhina (ps1) Konev Bor Akishino (aks) Domode Gubastovo (dm2) dovo Pan’shino (dm1) Yusupovo Lashma (ls) Rozhaika (kr3) Korob Nikitskoe (kr2) cheevo Staryi Yam (kr1) Kuznechiki (sh/kr) Shchu Lemeshevo (sh2) rovo Erinskaya (sh1) Dubrovitsy Devyatskoe (ak3) Staraya Ruza (ak2) Upper Ozery Ignat’evo(ak1) Lower Ozery Upper (mr2) Markovo Lower (mr1) Apraksino Baburinskaya (gr2) Gory Kamennaya (gr1) Sennitsa Creek Upper Vas’kino

Gorodenskaya (vs3) Lower Gorodnya (vs2)

Zybino (vs1) Kudrino Smedva not studied

not recognized

Peski

Afanas’evo (sv2)

Akatievo

Fusulina chernovi

Suvorovo

Upper

Neognathodus roundyi

Fusulina cylindrica Fusulinella bocki

Myachkovian P o d o l s k i a n

southern Kasimovskii Moscow Region District Ratchinskoe “Sharsha” (sv3) not studied

not studied

beds with rare Obsoletes sp. Streptognathodus and Fusiella subexcelsus lancetiformis

Neognathodus inaequalis

Krevyakinian Substage

Stage

Member Formation

2001a)

Putrella brazhnikovae Kashi rian

Kabanov (2003; Kabanov and Baranova, 2007)

Conodont zone Fusulinid zone after Goreva, Formation and member after Makhlina in Alekseev in after Isakova (2001) (Makhlina et al., (Makhlina et al., 2001a)

Protriticites ovatus

M o s c o v i a n

Upper Carboniferous (Pennsylvanian)

Kasimovian

Subsystem

Makhlina et al., 2001a, 2001b

within the Markovo–Peski interval in Voskresensk– Ozery area. This suggests that the Ulitino Formation of the Podolskian does not exist as a traceable lithostrati graphic unit and less than onethird of its interval was correlated correctly between individual sections. Of five formations proposed for the Podolskian (Fig. 5), the Vas’kino, Gory, Markovo, and Akatievo correspond to

Fig. 5. Correlation and cyclicity of the upper part of the Moscovian Stage and the lowermost Kasimovian Stage of central European Rus sia (modified from Kabanov and Baranova, 2007). Section indices are the same as in Fig. 1; subaerial disconformities: (SC) Sennitsa Creek, (Ap) Apraksino, (Oz) Ozery, (Db) Dubrovitsy, (Yu) Yusupovo, (KB) Konev Bor, (Ac) Achkasovo, and (Rt) Ratchinskoe. PALEONTOLOGICAL JOURNAL

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(a)

(c)

BARANOVA et al.

1 mm

1 mm

1 mm

(b)

1 mm

(d)

a?

(e)

1 mm

1 mm

(f)

Fig. 6. Aeolian, peritidal, and normal marine shoal facies: (a) aeolian grainstone (A2) top of Korobcheevo Formation, Konev Bor; (b, c) Meekella–Ortonella peloid grainstones (B1): (b) top of Peski Formation, Kasimovskii quarry; (c) top of the Gory Forma tion, Podolsk; (d) lagoonal calcimudstone (B2), Domodedovo Formation, Starye Peski; (e, f) normal marine shoal grainstones (C1): (e) Korobcheevo Formation, Domodedovo; (f) “gorokh” grainstone, Peski Formation, Domodedovo.

cyclothems of the same names. The Shchurovo Forma tion appears to be the lower (transgressive) and middle (maximum flooding or highstand) parts of the Shchurovo–Korobcheevo cyclothem (Kabanov, 2003; Kabanov and Baranova, 2007).

2.2. Lithofacies In the present study, we use the system of sedimen tary lithofacies published by Kabanov (2003). Each lithofacies is indexed (Figs. 6–8, Table 3). Four genetic groups of lithofacies are recognized: (A) land, PALEONTOLOGICAL JOURNAL

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1 mm

715

1 mm

(a)

(b)

1 mm

(c)

(d)

1 mm

1 mm

1 mm

(e)

(f)

Fig. 7. Normal marine subtidal facies: (a) smaller foraminiferal packstone–grainstone (BD), Korobcheevo Formation, Podolsk; (b, c) skeletal packstones–rudstones (D1): (b) Domodedovo Formation, Starye Peski; (c) Korobcheevo Formation, Nikitskoe; (d) shallowwater rudstone–packstone with claracrustan oncoids developed around echinoderm sclerites (lithofacies with mixed features of D1, D2, and C1), Gory Formation, Priokskii; (e) skeletal packstone (D2/D5), Akatievo Formation, Podolsk; and (f) offshore Zoophycos wackestone (D5), Gory Formation, Priokskii.

(B) peritidal, (C) normal marine shoal, and (D) nor mal marine subtidal. These groups correspond to widely accepted conceptual zonation of epicontinen tal seas (Irwin, 1965) and ramps (Burchette and PALEONTOLOGICAL JOURNAL

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Wright, 1993). Facies have a fundamental property of a lateral (environmental) contunuum (facies relays; Spence and Tucker, 1999), hence many, or even the majority of thin sections will show characteristics in

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5 mm

1 mm

(a)

(b)

a

a

1 mm (c)

5 mm (d)

Fig. 8. Normal marine subtidal facies (continuation): (a) microbial–algal boundstone (D3, biostrome with Ivanovia tenuissima Khvorova, 1946), Akatievo Formation, Podolsk; (b) microbial–algal grainstonetoboundstone (C1/D3) containing problemat icum Likinia nikitini Ilkhovskii, 1973; Korobcheevo Formation, Domodedovo; (c) proximal tempestite (D4), (a) fragments of phylloid algae, Markovo Formation, Priokskii quarry; and (d) distal tempestite (D6), Shchurovo Formation, Priokskii quarry.

between “pure” or model lithofacies. To avoid redun dant fragmentation of the facies spectrum, sections with transitional characteristics are designated through slash. For example, BD/D2 means that the texture is transitional between finegrained foramin

iferal grainstone and shallowsubtidal wackestone– packstone. Another example: the wackestone–pack stone of D2/D5 contains fewer markers of shallow water conditions (phylloid and dasycladacean algae, micritized grains) than a model shallowwater wacke PALEONTOLOGICAL JOURNAL

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Table 3. Lithofacies characterization. Rare lithofacies not shown in this table: (Do) oncoidal rudstones with nodules of Epivalvia/Bevocastria/Claracrusta (only Podolskian beds of the Maleevo section); (Dd) Donezella bafflestones (only Podolskian of Maleevo); (Tr) transgressive conglomerates in cyclothem bases (early transgressive reworking of regoliths)

Normal marine sand shoals

Semirestricted (stressed) peritidal

Subaerial

Sedimentary environment

Lithofacies (with its index) (A1) Continental claystones (shales) Gray, green, red, weathering into ochre, slickensided claystones and fissile shales, locally with distinct soil pedality and calcified root traces. Form discontinuous thin horizons less than 20 cm in thickness; occa sionally fill karstic pits and sinkholes where reach 2 m in thickness (limestoneshale breccia). Palygorskites in lower and middle Podolskian, illites and smectites in the Myachkovian (Kabanov et al., 2010). Charac teristically contain residual granules and pebbles of limestone and sometimes segregations of soil carbon ate. Syngenetic marine bioclasts absent. (A2) Aeolian grainstones (Fig. 6a) Limestone dunes up to 8 m tall described from the Myachkovian of Peski quarries (Khvorova, 1949). Fine grained (0.1–0.2 mm) calcretized grainstones; grains rounded, internally leached, encased in thin minimi critic envelopes. Penetrated by rhizocretions, Microcodium, and faecal pellets of small terrestrial inverte brates (Kabanov, 2005). Syngenetic marine bioclasts absent. (B1) Crossstratified Meekella–Ortonella and peloidal grainstones (Figs. 6b, 6c) These limestones form packages usually under 1 m in thickness crowning regressive parts of cyclothems, calcretized and karstified from the top. Cross lamination complex, frequently herringbone. In coarse grained varieties, laminae inclined at up to 25°–30°; laminae sets progressively less inclined in finer grained varieties. Typically contain intraclasts and brecciated lenses of calcimudstone pierced by burrows of “typeII” Scolithos (Kabanov, 2003). Alternation of fine and coarsegrained grainstones. Thin grain stone layers draped by microbial micritic crusts. Chraracteristic development of coquinas (pavements) of Meekella shells . Two populations of grains: (1) strongly rounded peloids and micritized bioclasts, nodules of Ortonella sp.; (2) autochthonous/parautochthonous nonrounded and weakly rounded fragments of Meekella shells. Notably poor fossil assemblages. (B1/B2) Microlayered very finegrained grainstones to calcimudstones Limestones with gently undulating microlamination. Transitional lithofacies between B1 and B2: fine to very finegrained (usually 50% of all grains). Composite lumps (graphestone aggregates), peloids, encrustation of Clar acrusta catenoides (Homann). Marine cements represented by micritic to micropeloidal automicrites and radial isopachous sparitic rims. Fossil assemblages normal marine, moderately to highly diverse. (C2) Ooid grainstones Rare limestone facies, known only from the Podolskian. Devyatovo Quarry (Podolsk District) formerly exposed 1.5 to 2m thick unit of finegrained (0.5–1 mm) wellsorted grainstone with indistinct cross strat ification. Ooids are mostly micritized and surrouned by radial isopachous cement rims. Fossil assemblage unusual, composed mostly of diverse allochthonous cephalopods arrived to the oolite shoal as necroplank ton (Kabanov et al., 2000).

(BD) Finegrained packstones–grainstones (Fig. 7a) Transitional from stressed Limestones massive, rarely retaining thin, gently inlined lamination. Usually grade from coarsergrained to normal lithofacies C1 and into packstones D2. Thalassinoid burrows and swirly bioturbation is common. Smaller– marine foraminiferal and peloidal grainstones, with strong micritization (>60–80% of grains micritized). Micritic cement form shells and plasmodesms between grains. Impoverished normal marine fossil assemblages. PALEONTOLOGICAL JOURNAL

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Table 3. (Contd.)

(D1) Skeletal packstones–rudstones (Figs. 7b, 7c) Limestones massive, locally indistinctly laminated (gently inclined trough crosslamination), thickbed ded, with patchy texture ranging from coarse to finegrained. Characteristic of the Korobcheevo Forma tion of Moscow Region. D1 units are usually composed of stacking 0.15–0.5mthick finingupward rhythms (minor parasequences) with rudstones in base and packstones in upper part. Colonial tetracorals (only in Korobcheevo Formation), tabulatomorphs, and chaetetids are characeristicaly abundant. Bio clasts mostly nonrounded, micritized grains rare or singular ( 1). Finally, cluster 3d can be named “a cluster of rare fusulinids.” This cluster collects thin sections with the average densities reaching 0.1 test sections/cm2 at most. Only six genera are present. Remarkably, cluster 3d shifted towards shallowwater stressed lithofacies,

where schubertellids and staffellids are the most per sistent components. 4.3. Facies Distribution of Myachkovian Fusulinids In the Myachkovian Substage, 10 out of 12 groups are common. The genera Beedeina and Putrella are singular (Fig. 38). Taitzehoella slightly upgrades from singular in the Podolskian to common in the Myachk ovain (xavg is just under 0.2 sections/cm2, δ < xavg in shallow normal marine facies). Similarly to the Podol skian Substage, two main regions in fusulinid distribu tion are a normal marine region with frequent and diverse fusulinids and a semirestricted peritidal region (lithofacies B1 and B2) with rare and lowdiversity fusulinids. In contrast to the Podolskian Substage, lagoonal calcimudstones B2 are represented here by a sufficient number of thin sections (n = 16). The litho facies BD with impoverished fossil assemblages in the facies model is placed in the transition between periti dal and normal marine regions. None of the fusulinid groups persist (δ > xavg), except for Eostaffella and schubertellids. In the Myachkovian Substage, schu bertellids seem most tolerant, since this is the only PALEONTOLOGICAL JOURNAL

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES 0.8 0.4 0 8.0

Eostaffella 1.0 0 Schubertellidae 1.0

4.0 0

0

Ozawainella

2.0

2.0 1.0

1.0 0

0

Neostaffella

1.0

1.0

Taitzehoella Fusulinella

Legend Average density in thin sections xavg Steadiness s = xavg/Dst

0 1.0 0.5 0

Confidence interval δ = ±Dstα

1.0

0.4 0 0.4 0.2 0

(n) number of thin sections in a given lithofacies

0

Fusulina

Lithofacies series

1.0 0

0.4

Beedeina

0.2 0

0

Putrella

0.10

1.0 0.5

0.05 0 4.0

1.0 0.5

0 1.0

Hemifusulina

Steadiness, s

Fusulinid density in thin sections, sec./cm2

0 0.10 0.05 0 0.8

(B1) crosslaminated grainstones with Meekella–Ortonella (n = 17) (BD+BD/D2) finegrained smaller foraminiferal packstones–grainstones and transitions to shallowwater packstones–grainstones (n = 19) (C1+B1/C1+B1/C2) shoal grainstones and transitions to crosslaminated and oolitic grainstones (n = 13) (D2) shallowwater skeletal packstones–wackestones (n = 26)

2.0

0.5

0 1.50

0 1.0

Parastaffelloides

0.5

0.75

0

0 3.0

Reitlingerina

D6

D5/6

D5

D4/6

D2/5

C1 + B1/C1 + B1/C2

Open shoal

D4 + D2/4

BD + BD/D2

Semilagoon

D2

B1 + B1/BD

Tidal flat

1.5 0

749

(D2/D5) shallow/deepwater skeletal packstones–wackestones (n = 5) (D4+D2/D4) proximal tempestites and transitions to shallowwater packstones–wackestones (n = 16) (D4/D6) proximal/distal tempestites (n = 11)

1.0

(D5) deepwater skeletal packstones–wackestones (n = 21)

0

(D5/D6) deepwater skeletal packstones–wackestones/distal tempestites (n = 11) (D6) distal tempestites (n = 35)

Open shallow subtidal

Open deep subtidal

Fig. 34. Distribution of Podolskian fusulinids over lithofacies. Lithofacies indices are explained in Table 3. Confidence intervals (δ) exceeding the mean values (xavg) are mostly omitted in diagrams. See Appendix 1 for data values. PALEONTOLOGICAL JOURNAL

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BARANOVA et al. 70 60 50 40 30 20 10 0 Cluster 2

3a Cluster 1

Distance between the most removed objects of clusters

750

3b

3c

3d

Cluster 3 Thin sections (n = 150)

Fig. 35. Analysis of 150 thin sections from Podolskian lithofacies with complete linkage clustering (ordinate is relative distance).

group recorded in lithofacies B2. The genera Eostaffella, Fusulinella, and Fusulina are also tolerant, as follows from their presence in all lithofacies except for B2. The genera Ozawainella, Neostaffella, and Taitzehoella do not occur in peritidal lithofacies B1. Hemifusulina and staffellids retain their facies prefer ence since the Podolskian. Staffellids are most abun dant (xavg > 1 sections/cm2) and most steady (δ < xavg) in normal marine shoal grainstone of C1. Amazingly, staffellids are not found in thin sections from lithofa cies D1, which is supposed to represent shallowwater euphotic conditions, supporting the highest diversity of skeletal benthos known in the Upper Moscovian (RauserChernousova and Reitlinger, 1954; Ivanova, 1958; Kabanov, 2003). It was previously suggested that tolerance window of staffellids narrowed towards shal lowerwater facies over the Podolskian–Myachkovian time span (RauserChernousova and Kulik, 1949; Baranova and Kabanov, 2003). Our new data do not support strong onshore shift of the staffellid facies range, or this shift was rather weak. Indeed, staffellids are present in minor quantity in the normal marine subtidal realm in both Podolskian and Myachkovian (Figs. 34, 38). Complete linkage clustering of the samples from the Myachkovian Substage has produced three main clusters (Fig. 39). The greatest number of thin sections went into cluster 2, which can be divided into four lowerorder clusters: 2a, 2b, 2c, and 2d (Fig. 39). Clusters 1 and 2d mostly collect normal marine sub tidal lithofacies, including BD (Fig. 40). These clus

ters can be called schubertellid–fusulinellan (Fig. 41). Cluster 2d differs from cluster 1 in the fewer fusulinids, whose presence is unsteady. Only schubertellids show the average density exceeding 1 section/cm2. Clusters 2a, 2b, and 2c have peaks in lithofacies C1; however, these clusters differ from each other in the density of fusulinids. Cluster 2a is dominated by the genus Fusulina (xavg = 6.1 sections/cm2, s > 2). This cluster builds on and around the Fusulinarich “gorokh” grainstones of lithofacies C1. Schubertellids, Fusulinella, and Ozawainella also persist in this cluster. The density of staffellids is significant (xavg > 1 sections/cm2 for Parast affelloides). Cluster 2b is a Fusulinella–schubertellid grouping, and cluster 2c builds on Fusulinella, schuber tellids, and Fusulina. In both clusters, staffellids are infre quent (xavg < 0.3 sections/cm2) and unsteady (s < 0.7). Cluster 3 bundles peritidal lithofacies B1, B2, and BD, where fusulinids are rare or singular, with the average density below 0.4 sections/cm2 and stability not exceed ing 1. Schubertellids are most persistent in this cluster (s = 0.7). 4.4. Changes in Facies Preferences of Fusulina An interesting time trend is revealed in facies distri bution of the genus Fusulina (Fig. 42). During the Pod olskian Time, Fusulina is rare (xavg ≤ 0.2 sections/cm2) and found in normal marine subtidal facies. No fusuli nas are found on grainstone shoals in stressed peritidal facies. This genus is stably present in Shchurovo off PALEONTOLOGICAL JOURNAL

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES k 100

Cluster 2

80

60

60

60

40

40

40

20

20

20

0

0

0

k 100

Cluster 3b

k 100

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

80

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

80

Cluster 3c

k 100 80

60

60

60

40

40

40

20

20

20

0

0

0

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

80

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

80

Cluster 3a

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

k 100

Cluster 1

Cluster 3d

B1 + B1/BD C1 + B1/C1 + B1/C2 BD BD/D2 D2 D2/4 + D4 D2/5 D4/6 D5 D5/6 D6

k 100

751

Fig. 36. Distribution of lithofacies in clusters from Fig. 35; X axis shows continuous series of lithofacies; Y axis shows k (%) = nlf/Nlf, where nlf is the number of thin sections in a given lithofacies in a given cluster, Nlf is the total number of thin sections in Podolskian dataset.

shore wackestones and tempestites (s > 1). During Korobcheevo Time, Fusulina habitats apparently shifted onshore, as suggested by its massing in the lithofacies C1 (up to 8.9 sections/cm2) in the borehole Akishino (Fig. 27). However, the majority of shoal grainstones in the Korobcheevo Formation lack Fusulina, while deeperwater packstones and wacke stones usually contain this genus (s > 1). During the Domodedovo Time, rare Fusulina persisted in normal marine shoal conditions (xavg = 0.3 sections/cm2, s = 1.2). Since the beginning of the Peski Time, Fusulina grows in number in all facies but shows a distinct peak in and around lithofacies C1 (xavg = 3.5 sections/cm2). The Myachkovian Fusulinarich grainstones have been known in historical stone pits around Moscow as “gorokhs,” that is, “pea stones.” Since many sub PALEONTOLOGICAL JOURNAL

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Peski grainstones lack Fusulina, its average steadiness for the Myachkovian is relatively low (s = 0.96). 4.5. Criteria for Fusulinid Biofacies The fusulinid biofacies are recognized based on the following parameters (Figs. 43, 44): the number of taxa of the same rank (richness); Shannon index of diversity (H); Berger–Parker index of domination (d) (Magurran, 2004), and the density of groups regarded as biofacies indexes. In Figs. 34 and 38, almost all groups tend to decrease in abundance and (or) steadiness onshore from lithofacies C1. Staffellids show the most pro nounced disagreement to this trend. Therefore, two abundance parameters are introduced: Kfus for the fusulinid number, excluding Staffellida and Kst as a

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1

xavg 10

0.1

0.1

0.01

0.01

Schubertellidae Neostaffella Ozawainella Fusulinella Fusulina Eostaffella Beedeina Taitzehoella Hemifusulina Putrella Parastaffelloides Reitlingerina

1

Cluster 3c

xavg 10 1

0.1

0.1

0.01

0.01

Schubertellidae Eostaffella Ozawainella Neostaffella Fusulinella Beedeina Reitlingerina Hemifusulina Taitzehoella Parastaffelloides Putrella Fusulina

1

Average density xavg

Cluster 3b

Parastaffelloides Reitlingerina Schubertellidae Eostaffella Neostaffella Ozawainella Fusulinella Taitzehoella Fusulina Beedeina Putrella Hemifusulina

Cluster 3a

0.01

Schubertellidae Eostaffella Beedeina Neostaffella Ozawainella Fusulina Fusulinella Hemifusulina Parastaffelloides Reitlingerina Taitzehoella Putrella

0.1

1

xavg 10

Cluster 2

Cluster 3d

Schubertellidae Reitlingerina Hemifusulina Eostaffella Fusulinella Parastaffelloides Ozawainella Neostaffella Taitzehoella Beedeina Fusulina Putrella

xavg 10

xavg 10

Cluster 1

Schubertellidae Hemifusulina Eostaffella Ozawainella Neostaffella Taitzehoella Fusulinella Fusulina Beedeina Putrella Parastaffelloides Reitlingerina

xavg 100 10 1 0.1 0.01

Steadiness (s)

Fig. 37. Distribution of genera in clusters from Fig. 35. Sorting, in order of decreasing steadiness s = xavg/ Dsq, where xavg is the average taxon density in a lithofacies and Dsq is standard square deviation.

staffellid number (Figs. 43, 44). Both parameters are expressed in test sections per cm2. There is a need to select groups that do not change their facies preference in the Podolskian–Myachkovian time interval and show sufficient abundance and persistence to charac terize certain parts of the facies range. The genera Ozawainella and Fusulinella are almost absent in litho facies B1 and B2 and extremely rare in lithofacies BD, but persisting offshore from the stressed peritidal belt over the Podolskian–Myachkovian stratigraphic interval. No fusulinids show preferential habitats in stressed tidalflat settings. However, lithofacies B1 and B2 show steady presence of schubertellids in lagoonal calcimudstones B2 (s reaching 1.46; Fig. 44). In the

Podolskian Substage, the genus Fusulina is a marker of normal marine subtidal facies, although it changes facies preferences with time (Fig. 42). The genus Hemifusulina shows extremely variable distribution and forms specific assemblages in subtidal storm affected facies. Based on criteria delineated above (Figs. 43, 44), we recognize three main fusulinid biofacies and two subordinate (more specific) biofacies. The main ones are the biofacies of Fusulinella–Ozawainella, Staffell ida, and impoverished Schubertellidae assemblages. Two more specific biofacies describe Staffellida– Fusulina and Hemifusulina assemblages (Figs. 45, 46). PALEONTOLOGICAL JOURNAL

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES Eostaffella

0.4

2.0 1.0 0

0.2 0 5.0

753

Schubertellidae

2.0 1.0

0 1.2 0.6 0 0.6 0.3 0 0.2 0.1 0 5.0

0 2.0 1.0 0 1.0 0.5 0 1.0 0.5 0 2.0

Ozawainella

Neostaffella

Taitzehoella

Fusulinella

1.0

2.5 0 4.0

Steadiness, s

Fusulinid density in thin sections, sec./cm2

2.5

0 2.0

Fusulina

1.0

2.0 0 0.10 0.05 0 5.0 2.5 0 5.0

0 0.5

Beedeina

Legend Average density xavg Steadiness s = xavg/Dst Confidence interval δ = ±Dstα (n) number of thin sections in given lithofacies Lithofacies series (B1) crosslaminated grainstones with Meekella–Ortonella (n = 15) (B2) lagoonal calcimudstones and lagoonal calcimudstones with thin storm interbeds (n = 16) (BD) finegrained smaller foraminiferal packstones–grainstones (n = 13) (BD/D2) finegrained packstones–grainstones/shallowwater packstones (n = 8) Shoal grainstones “gorokh”/skeletal packstones–rudstones (n = 6)

0 1.0 0.5

(C1/D2) shoal grainstones “gorokh”/shallowwater skeletal packstones–wackestones (n = 14)

0 1.0

(D1) skeletal packstones–rudstones (n = 26)

0.5

(D1/D2) skeletal packstones–rudstones /shallowwater skeletal packstones–wackestones (n = 15)

0 1.0

(D2) shallowwater skeletal packstones–wackestones (n = 85)

0.4

0.5

0 1.4

0

(D2/D5) shallow/deepwater skeletal packstones–wackestones (n = 15) (n = 17)

1.0

(D4) proximal tempestites (n = 9)

0

(D4/D6) proximal/distal tempestites (n = 17)

Putrella

Hemifusulina

2.5 0 0.8

Parastaffelloides

Reitlingerina

(D5) deepwater skeletal packstones–wackestones (n = 10) (D6) distal tempestites (n = 14)

Open shoal

Semilagoon

Tidal flat

0

B1 B1 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

0.7

Open shallow Open deep subtidal subtidal

Fig. 38. Distribution of Myachkovian fusulinids over lithofacies range. Confidence intervals (δ) exceeding the mean value xavg are mostly cut off. See Appendix 2 for δ data values. PALEONTOLOGICAL JOURNAL

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754 60 50 40 30 20 10 0

2a 2b

2c

Cluster 1

2d Cluster 2 Thin sections (n = 239)

Cluster 3

Fig. 39. Analysis of 239 thin sections from Myachkovian lithofacies with complete linkage clustering.

k 100

Cluster 2a

k 100 80

60

60

60

40

40

40

20

20

20

0

0

0

k 100

Cluster 2c

k 100

B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

80

B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

80

Cluster 2d

k 100

80

80

60

60

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40

40

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20

0

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B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

80

B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

Cluster 2b

B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

Cluster 1

Cluster 3

B1 + B1/D2 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/4 + D4 D2/5 D5/6 D5/6 + D5 D6

k 100

Fig. 40. Distribution of lithofacies in clusters from Fig. 39; X axis shows continuous series of lithofacies; Y axis shows k (%) = nlf/Nlf, where nlf is the number of thin sections in a given lithofacies in a given cluster, Nlf is the total number of thin sections in the Myachkovian dataset. See Figs. 34 and 38 and Table 3 for lithofacies indices. PALEONTOLOGICAL JOURNAL

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FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES xavg 10 1

0.1

0.1

0.01

0.01

Schubertellidae Eostaffella Fusulinella Fusulina Ozawainella Neostaffella Parastaffelloides Reitlingerina Hemifusulina Beedeina Putrella Taitzehoella

1

xavg 10

Cluster 2b

1

0.1

0.1

0.01

0.01

xavg 10

Fusulinella Schubertellidae Eostaffella Ozawainella Neostaffella Parastaffelloides Reitlingerina Fusulina Hemifusulina Taitzehoella Putrella Beedeina

1

xavg 10

Cluster 2d

1

0.1

0.1

0.01

0.01

Fusulinella Schubertellidae Eostaffella Ozawainella Fusulina Taitzehoella Neostaffella Hemifusulina Reitlingerina Parastaffelloides Putrella Beedeina

1

Cluster 2c

Fusulinella Schubertellidae Fusulina Ozawainella Eostaffella Hemifusulina Neostaffella Parastaffelloides Taitzehoella Beedeina Reitlingerina Putrella

xavg 10

Cluster 2a

Fusulina Schubertellidae Fusulinella Ozawainella Eostaffella Reitlingerina Neostaffella Hemifusulina Taitzehoella Parastaffelloides Beedeina Putrella

Cluster 1

Cluster 3

Schubertellidae Fusulinella Reitlingerina Eostaffella Parastaffelloides Hemifusulina Fusulina Ozawainella Taitzehoella Putrella Neostaffella Beedeina

xavg 10

755

Average density in thin sections xavg

Steadiness (s)

Fig. 41. Distribution of genera in clusters from Fig. 38. Sorting, in order of decreasing steadiness s = xavg/Dsq, where xavg is the average density of genus in lithofacies and Dsq is standard square deviation. The genus persists at s > 1 and occurs sporadically at s < 1.

4.6. Fusulinella–Ozawainella Biofacies This biofacies is rich in fusulinids but lacks staffell ids, which covers a wide range of normal marine sub tidal facies to the right of lithofacies C1 in Figs. 34, 38, 43, and 44. Fusulinid assemblages are highly variable, which complicates recognition of index groups. Taxo nomic richness is mostly greater than 4 at the genus level; Kfus is mostly greater than 4 sections/cm2. In the Podolskian Substage, this biofacies features the high PALEONTOLOGICAL JOURNAL

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est diversity (Havg = 1.4 in lithofacies D5), and the low est domination (davg = 0.44 in the same lithofacies) for the entire facies spectrum. In the Myachkovian Sub stage, the diversity of nonstaffellid offshore assem blages (0.9 < Havg < 1.4) and domination (0.4 < d < 0.6) are lower than in the normal marine shoal assemblages of lithofacies C1 (Fig. 44). The Fusulinella–Oza wainella biofacies can be referred to as a nonstaffellid biofacies with a degree of condition, because repre

BARANOVA et al.

Average density of genus Fusulina xavg Steadiness (s) (B1) crosslaminated grainstones with Meekella and Ortonella

Domodedovo Formation

(B2) lagoonal calcimudstones and lagoonal calcimudstones with thin storm interbeds

Akatievo Formation Korobcheevo Formation

D5 + D5/6 D6 D5 + D2/5 D4/6 + D6

D4 + D4/6

D4 + D4/6 D2 D5/6

D2/5 D1 + D1/2 D5 + D2/5

D4 + D2/4

C1 + C1/D1

D1 + D1/2

D2

D2

C1 + C1/D2 + C1/D7 C1 + C1/D1 + C1/D2

BD + BD/D2 + BD/D7 B1 + B2 + B2/D4 Shallo

BD + BD/D2

xavg 2.0 1.5 1.0 0.5 0

D2

xavg 2.0 1.5 1.0 0.5 0

B1 + B1/C1 + B2

Time

xavg 2.0 1.5 1.0 0.5 0

B1 + B1/BD + C1

xavg 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0

Peski Formation

756

(BD) finegrained smaller foraminiferal packstones–grainstones (BD/D2) finegrained packstones–grainstones/ shallowwater packstones (C1) shoal grainstones “gorokh” (C1/D1) / shoal grainstones “gorokh”/ skeletal packstones–rudstones (C1/D2) shoal grainstones “gorokh”/ shallowwater skeletal packstones–wackestones (D1) skeletal packstones–rudstones (D1/D2) skeletal packstones–rudstones/ shallowwater skeletal packstones–wackestones (D2) shallowwater skeletal packstones–wackestones (D2/D5) shallow/deepwater skeletal packstones–wackestones (D4) proximal tempestites (D4/D6) proximal/distal tempestites (D5) deepwater skeletal packstones–wackestones (D6) distal tempestites (D7) open marine calcimudstones

w in g

Fig. 42. Expansion of the genus Fusulina into shoal habitats from the Middle Podolskian (Akatievo Formation) to the Late Myachkovian (Peski Formation).

sentatives of Staffellida sporadically occur on the onshore flank of this facies range (Figs. 43, 44). In the Podolskian sample set, this biofacies is characterized by the presence of the following genera (in decreasing order of xavg): Neostaffella, Ozawainella, Fusulinella, Beedeina, and Fusulina. In the Myachkovian, this bio facies is defined by Fusulinella, Ozawainella, and Fusulina (in decreasing order of xavg). Hemifusulina is characteristically rare (xavg ≤ 0.3 sections/cm2) or

absent in many samples. It is remarkable that lithofa cies D5 and its vicinity (lithofacies D2/D5, D5/D6) maintain the most constant taxonomic richness, non staffellid fusulinid number Kfus, and domination (high s and low δ in Figs. 43, 44). In the Podolskian dataset, this part of facies shows the maximum diversity and the least extent of domination (Fig. 43). In the Myachkovian dataset, two main diversity peaks within this biofacies are observed in lithofacies D5 to D2/D5) PALEONTOLOGICAL JOURNAL

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xavg 8

6

D6

D5/6

D5

D4/6

D2/5

D4 + D2/4

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

0

B1 + B1/BD

3

D6

D5/6

D5

D4/6

D6

D5/6

D5

D4/6

D6

D5/6

D5

D4/6

s 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

s 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

1.2

0.8

1.0 0.6

0.8

0.4

0.6 0.4

0.2 0

Average xavg Confidence interval δ

s 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

s 1.4

Fusulinella, sec./cm2

Steadiness s

0.2 D6

9

xavg 1.0

D5/6

12

s 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

D5

Fusulinid number Kfus (excluding staffellids)

D4/6

D6

D5

D2/5

D5/6

0

D4/6

0

D4 + D2/4

0

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

0.5

B1 + B1/BD

1

Ozawainella, sec./cm2

D2/5

0

D2/5

2

0.2

xavg 15

D2/5

4

D2/5

0.4

D4 + D2/4

0.6

D4 + D2/4

D6

D5/6

D5

D4/6

D2/5

D4 + D2/4

6

xavg s 2.5 4 2.0 3 1.5 2 1.0

Domination index d

D4 + D2/4

xavg 0.8

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

0

B1 + B1/BD

0.4

Schubertellidae, sec./cm2

D4 + D2/4

0.8

0

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

1.2

1

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

1.6

2

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

D6

D5/6

D5

D4/6

D2/5

D4 + D2/4

s 6 5 4 3 2 1 0

Diversity index H

3

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

xavg 2.0

BD + BD/D2 C1 + B1/C1 + B1/C2 D2

0

B1 + B1/BD

2

Staffellid number Kst

B1 + B1/BD

4

xavg 4

B1 + B1/BD

6

s 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0

B1 + B1/BD

Number of taxa

B1 + B1/BD

xavg 8

757

0

Fig. 43. Indicators of main Podolskian fusulinid biofacies. In all diagrams, left Y axis shows the Xavg and confidence interval δ; right Y axis shows steadiness s. PALEONTOLOGICAL JOURNAL

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4

0

xavg 2.0

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

2

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

0.8 0.6 0.4

0

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

0.2

1.5 1.0 0.5 0

s 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0

xavg 1.2

0.5

Domination index d

2.0

xavg 5

1.0

xavg 1.0

xavgFusulinid number Kfus (excluding staffellids) s 3.0 15 2.5 12 2.0

9

1.5 6

1.0 0.5

0

0

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

3

Average xavg

Confidence interval δ

Staffellid number Kst

s 8 7 6 5 4 3 2 1 0

Diversity index H

1.5

0

xavg 2.5

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

6

s 6 5 4 3 2 1 0

Schubertellidae, sec./cm2

s 1.2 1.0 0.8 0.6 0.4 0.2 0

s 2.5

4

2.0

3

1.5

2

1.0

1

0.5

0

0

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

Number of taxa

Ozawainella, sec./cm2

0.9 0.6 0.3 0

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

xavg 8

xavg 7 6 5 4 3 2 1 0

Steadiness s

Fusulinella, sec./cm2

B1 B2 + B2/D4 BD BD/D2 C1 C1/D1 C1/D2 D1 D1/2 D2 D2/5 D4 D4/6 D5 D6

758

s 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

s 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0

Fig. 44. Markers of the main fusulinid biofacies of the Myachkovian Substage. In all diagrams, left Y axis shows Xavg and confi dence interval δ; right Y axis shows steadiness s. PALEONTOLOGICAL JOURNAL

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Staffellidae

Ozawainella– Fusulinella

FUSULINIDS (FORAMINIFERA), LITHOFACIES AND BIOFACIES

759

Podolskian Time

Hemifusulina

Lithofacies (A1) arid plains (pedogenesis)

General biofacies Meekella–Ortonella

(A2) aeolian grainstones

Staffellid–syphonean (B1) crosslaminated grainstones with Ortonella Extended bryonoderm biofacies (B2) lagoonal calcimudstones Fusulinid biofacies boundaries

(BD) smaller foraminiferal packstones–grainstones (C1) coarsegrained rounded grainstones «gorokh»

Index genera of fusulinid biofacies Schubertella/ Fusiella

Ozawainella

Fusulinella

Parastaffeloides/ Reitlingerina

Hemifusulina

(D1) skeletal packstones–rudstones (D2) shallowwater–subtidal skeletal packstones–wackestones (D4) proximal tempestites (D5) Zoophycos packstones and wackestones (D6) distal tempestites, (D7) deep subtidal calcimudstones

Fusulina

Fig. 45. Podolskian fusulinid biofacies in the facies model of the Late Moscovian epeiric sea of southern Moscow Basin (including Oka–Tsna Swell).

and in the vicinity of lithofacies D1. The genera Fusulinella, Ozawainella, and Neostaffella also show peaks of steadiness s in the vicinity of lithofacies D5 and D1 (Figs. 34, 38, 43, 44). In the Podolskian Sub stage, lithofacies D1 is poorly represented. Both D5 and D1 virtually lack staffellids. We believe that sedi mentary environments of lithofacies D5 and D1 with their optimal for benthic life and least disturbed regimes might have represented the cradles of well defined fusulinid biofacies within generally unstable shallow subtidal realm, where small benthic forms were frequently dispersed by storms. PALEONTOLOGICAL JOURNAL

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4.7. Staffellid Biofacies The staffellid biofacies is determined by Kst > 0.2. In the Podolskian Substage, 1 < Kfus < 4. In the Myach kovian, Kfus varies between 3.5 and 9.5 (Fig. 43). In the Podolskian Substage, this biofacies shows less taxo nomic richness and diversity and higher domination than the Fusulinella–Ozawainella biofacies (Fig. 43; Appendix 1). However, in the Myachkovian, the staffellid biofacies features the greatest diversity and the least domination in the entire facies range (Havg ≥ 1.62, davg ≤ 0.32 in lithofacies C1/D1). The composition of nonstaffellid fusulinid assemblages is

Impoverished Schubertellidae

Staffellidae

BARANOVA et al.

Ozawainella– Fusulinella

760

Staffellidae– Fusulina Myachkovian Time

Hemifusulina

Fig. 46. Myachkovian fusulinid biofacies in the facies model of the Late Moscovian epeiric sea of southern Moscow Basin (including Oka–Tsna Swell). See Fig. 45 for legend.

variable, including all forms characteristic of the off shore Ozawainella–Fusulinella lithofacies. In the Pod olskian Substage, Neostaffella (xavg = 0.4 sections/cm2, savg = 0.75) and schubertellids (xavg = 1.0 sections/cm2, savg = 0.6) are the most persistent forms. In the Myach kovian, the most constant presence is shown by schu bertellids (xavg ≤ 4.4 sections/cm2, savg ≤ 1.0), Fusulinella (xavg ≤ 1 sections/cm2, savg ≤ 0.6), and, to a lesser extent, Eostaffella and Ozawainella (Fig. 38). The genus Fusulina became the leading component in the Myachkovian staffellid biofacies, defining specific staffellid–Fusulina biofacies. The core staffellid biofa cies occupied the shallowest subtidal to shoal to open backshoal lagoon environments just below and above the FWWB (BD–B1/C1–C1–C1/D1–C1/D2 litho facies range). However, Kst exceeds 0.2 sections/cm2 in some shallowwater wackestones, packstones, and tem pestites of lithofacies D2, D1/2, and D4 (Figs. 43, 44, Appendices 1, 2). This is particularly the case in the Podolskian. Such oozy facies may be classified into staffellid biofacies; however, there is a high probability of test transport offshore from nearby shoals. Thus, it is evident that the limits between fusulinid biofacies may crosscut lithofacies transitions.

4.8. Impoverished Schubertellid Biofacies This biofacies describes poor fusulinid assemblages with Kfus ≤ 1, rarely, up to 1.5 sections/cm2, and schu bertellids being the only persisting group (Figs. 34, 38, 43, 44). This biofacies corresponds to marginal marine lithofacies B1, B2, and partly BD. In Podolskian grainstones belonging to that range, staffellids reach the greatest abundance and steadiness (xavg = 0.7 sec tions/cm2, s = 1.2). In the Myachkovian Substage, the presence of staffellids becomes ephemeral (s = 0.3) and the total genuslevel diversity of fusulinids falls to the minimum (only schubertellids in lithofacies B2). Two modifications of the impoverished schubertel lid biofacies are recognized. The Podolskian–Korob cheevo modification is brisker than the younger Myachkovian one and can be named the “impoverished staffellid biofacies.” Each thin section of such grain stones count at least two fusulinid groups, Havg ≈ 0.8, davg ≈ 0.6, staffellids and schubertellids persist, and most of other normal marine genera, such as Eostaffella, Ozawainella, Neostaffella, Fusulinella, and Hemifusulina, sporadically occur (Figs. 34, 38). The impoverished staffellid biofacies is expressed in clus ters 3b and 3d of the Podolskian dataset (Figs. 35–37). PALEONTOLOGICAL JOURNAL

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Lithofacies B1 and BD hosting these assemblages adjoin normal marine lithofacies in the section and may interfinger with them laterally. It is also not unlikely that sporadically occurring genera were thrown onshore from subtidal settings by storms and (or) tide currents. The second variety of this biofacies is represented by rare schubertellids occasionally added by very rare staffellids. Kfus < 0.4 sections/cm2 and generic diversity is mostly 1, 2, or 0 (that is, no fusulinids are present). The indices of diversity and domination do not have any resolution because of scarcity of fusulinids (Appendix 2). This modification of biofacies is expressed in cluster 3 of Myachkovian dendrogram (Figs. 39–41) and mostly corresponds to lagoonal cal cimudstones B2 and overlying crosslaminated grain stones B1. These thick shallowlagoonal to tidalflat packages occur in the Domodedovo Formation and partly (in the Kasimovskii District) in the Korob cheevo Formation. Bed 32 in the top of the Peski For mation at Kasimovskii quarry is composed of wacke stones D2 (with strongly impoverished assemblage of benthic fossils (Figs. 28, 29), which makes it similar to lagoonal calcimudstones B2. Overlying grainstones of Bed 33, which contain singular schubertellids and staffellids (Figs. 28, 29), are also linked to the second (Myachkovian) variety of impoverished schubertellid biofacies. In case of the Myachkovian, the tidal flats and shallow lagoonal pools with restricted connection to normal seawaters were likely barred from normal marine habitats, impeding further onshore propaga tion of the most tolerant forms. Unfortunately, the Podolskian dataset does not collect a sufficient num ber of samples from lithofacies B2. Two thin sections from this lithofacies were obtained from the transgres sive part of the Gory cyclothem. These thin sections lack fusulinids. Based on this, transgressive calcimud stone of the Gory cyclothem is closer to the second (Myachkovian) variety of biofacies. 4.9. Staffellida–Fusulina Biofacies This biofacies is recognized based on a high (>5 sections/cm2) concentration of Fusulina coupled with the presence of staffellids. Such assemblages prone to sandshoal habitats are found starting from the Korobcheevo Formation upwards. In the Peski For mation, they become dominant in lithofacies C1 in delineating by that the Myachkovian modification of staffellid biofacies. The wackestones–packstones of lithofacies D2 from the Kamennaya Tyazhina Mem ber at Afanasievo (AF) also contain staffellids (Fig. 15) and, therefore, should be grouped into the staffellid– Fusulina biofacies. The staffellid–Fusulina biofacies is expressed in cluster 2a of Myachkovian dendrogram (Fig. 41). PALEONTOLOGICAL JOURNAL

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4.10. Hemifusulina Biofacies The Hemifusulina biofacies is a compact group of moderately impoverished (H < 1) fusulinid assem blages dominated by the genus Hemifusulina (d > 0.7). Hemifusulina sometimes forms monospecific accu mulations (Fig. 47; Pl. 26, fig. 3). The Hemifusulina biofacies is only observed in wackestones, calcimud stones, and muddy (muddominated) tempestites of regressive parts of cyclothems (D7–D5/D6–D4/D6– D4 lithofacies range). This biofacies has been encoun tered twice (Fig. 47): in the Vas’kino Formation of the Gory section (Hemifusulina communis) and in the Gubastovo Member of the Domodedovo Formation of the Peski section (Hemifusulina bocki). The existence of special Hemifusulina assemblages confined to certain facies was previously admitted by RauserChernousova and Reitlinger (1954). However, in other basins, species of the genus Hemifusulina do not show a tendency to occur in similar facies. In par ticular, Moscovian Hemifusulina of the Asturian Basin thrived in highenergy shallowwater conditions (Ginkel, 1973). The morphologically similar genus Ferganites from the Kasimovian–Gzhelian of the same basin was also adapted to nearshore conditions (Villa and Bahamonde, 2001). The regressive packages with mass Hemifusulina (Fig. 47) also have a distinct signature in other fossil groups: they virtually lack algae, and most groups of benthic skeletal metazoans likely show a somewhat depressed taxonomic richness. However, fenestellid bryozoans are diverse and abundant (Kabanov et al., 2006). The Hemifusulina assemblage apparently devel oped in relatively deepwater conditions affected by some adverse factors. These factors could have been intermittently oozy ground, stagnant, lowoxygen bottom waters (evidenced by weakened bioturbation), or increased seasonal fluctuations of salinity. 4.11. Biofacies and Sea Level Fluctuations To recognize distinctions between transgressive (T), distal or highstand (D), and regressive (R) fusulinid assemblages, we analyzed data samples from respective parts of cyclothems (Fig. 48). Peritidal lithofacies with impoverished schubertellid assem blages were excluded, because they are present mostly in terminal regressive parts of cyclothems having biotic signatures quite disparate from normal marine facies. Including them would increase the deviation of results. The data samples from the Vas’kino–Korob cheevo interval with relatively distinct T, D, and R parts were handled separately from the Domode dovo–Peski dataset with poorly distinguishable trans gressive and regressive trends within two main cyclothems (Fig. 5; Kabanov et al., 2006; Kabanov and Baranova, 2007).

762

BARANOVA et al.

8a 7 6

0

5 10 15 20 25 30 0 10 20 30 40 0 0.5

0 0.4 0.8

Shannon diversity index (H)

Berger–Parker domination index (d)

Staffellid number (Kst)

Hemifusulina, sections/cm2

0

1.5

5a

Hemifusulina biofacies

D2 D2 D4 D4/6 D5/6 D6 D5/6 D5/6

5c 5b

Vas’kino

Land Tidal flat, shoal, lagoon Shallow subtidal Deep subtidal

1m

Gory

Formation Member Bed no.

Lithofacies

Sea

Fusulinid number (excluding staffellids) Kfus

(a)

D7

4

D7

3b D4/6 D6 D7 D6

3a 2

?

11 21 10 20 19 8 18 6 16 5 15 4b 14b 4a 14a

Pan’shino

3 13 2 12

Staffellid number (Kst)

Berger–Parker 0.8 domination index (d) 1.2 0 1.6 Shannon diversity 1.2 index (H) 1.8

0.4

5 10 15 20 25 30 0 10 20 30 40

0 1 2 0

Lithofacies

Land Tidal flat, shoal, lagoon Shallow subtidal Deep subtidal

0

B1 B2 B2/D4 D1/4 D4/6 D6 D7 D6 D6 D2/5 D2/5 D4/6 D4 C1

Hemifusulina biofacies

Domodedovo Gubastovo

12 22

1m

Formation Member Bed no. Starye Peski Bed no. Konev Bor 24 13 23

Hemifusulina, sections/cm2

Fusulinid number (excluding staffellids) Kfus

(b) Sea

D2 D2/5 D2

1 11

D1 D2

10

D2 D2

Fig. 47. Hemifusulina biofacies: (a) made by Hemifusulina communis Rauser, 1951 in Vas’kino Formation (Gory section, Podolskian); (b) made by Hemifusulina bocki Moeller, 1878, Gubastovo Member of Domodedovo Formation, Myachkovian Substage, Peski. PALEONTOLOGICAL JOURNAL

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10

Vas’kino–Korobcheevo interval Regressive facies n = 114 Havg = 1.0 d = 0.57

10

5.24

0.41 0.16

0.78 0.33

029

0.1

0.1

0.04 0.03

Distal facies n = 52 Havg = 1.26 d = 0.48

10

0.05

1

0.57

0.43

0.41

0.17 0.14 0.07

0.1

0.01

Distal facies n = 30 Havg = 1.25 d = 0.46

10

5.88

1.09 0.82

1.28

0.28 0.06 0.01

0.01 0.001 10

3.81

Transgressive facies n = 28 Havg = 0.97 d = 0.57

0.001 6.94

0.51

0.70

0.79

0.54

0.16

10 1

0.32

0.44 0.15

0.1

0.02

0.04

0.02

0.02

0.001 Kfus

Average density xavg

0.01 0.01

0.01 Eostaffella Schubertellidae Ozawainella Neostaffella Taitzehoella Fusulinella Fusulina Beedeina Putrella Hemifusulina Parastaffelloides Reitlingerina

0.01 0.001

0.49 0.19

0.13 0.12

5.20

1.18 1.28

Eostaffella Schubertellidae Ozawainella Neostaffella Taitzehoella Fusulinella Fusulina Beedeina Putrella Hemifusulina Parastaffelloides Reitlingerina

0.1

0.08

0.02

Transgressive facies n = 51 Havg = 0.97 d = 0.48 1.97

1

0.01

0.01

0.01 0.01

4.44

0.64

0.25

0.1

0.04

0.02

0.01

0.001

2.12 0.93 0.99

1.01 0.53

0.45

0.01

0.001

7.07

0.21

0.08

0.05

1.23

1

0.19

0.01

1

3.63

1.37

1.77

1

Domodedovo–Peski interval Regressive facies n = 53 Havg = 0.86 d = 0.65

763

Kfus

Steadiness s

Fig. 48. Distribution of fusulinids in the transgressive, highstand, and normal marine regressive parts of cyclothems in the Vas’kino–Korobcheevo dataset (left column) and the Domodedovo–Korobcheevo dataset (right column); vertical axis is loga rithmic. Values of the average density are marked. Kfus is the fusulinid number excluding Staffellida; n is the number of thin sec tions in the sample; Havg is the mean of the Shannon diversity index; davg is the mean of the Berger–Parker domination index.

Figure 48 does not reveal significant difference between T, D, and R samples in the Vas’kino–Korob cheevo interval. The D sample set differs from T and R samples in the greatest diversity and somewhat smaller extent of domination among nonstaffellid groups, and also in the presence of singular staffellids (xavg ≤ 0.02 sections/cm2). Remarkably, the T set from the Vas’kino–Korobcheevo interval is enriched with schubertellids (xavg = 3.8 sections/cm2, s is up to 2.2) in comparison with D and R sets. The Domodedovo– Peski sample set shows inverse pattern, with somewhat more abundant schubertellids in the R set, although their abundance is fluctuating. In the Domodedovo– Peski interval, the T set is distinctly enriched with staffellids as a result of sample enrichment by shallow water forms from ”gorokh” grainstones. The most dis PALEONTOLOGICAL JOURNAL

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tinct asymmetry is observed in the distribution of the genus Beedeina in the Vas’kino–Korobcheevo inter val. Beedeinas show the greatest abundance in the T set (xavg > 0.5 sections/cm2); in D and R datasets, the number of Beedeina gradually decreases to rare and sporadic (xavg = 0.04 sections/cm2 at s = 0.25). In the Upper Myachkovian, Beedeina declines to singular and only occasionally occur in T and R datasets. An increase in number of the genus Hemifusulina in R samples of both stratigraphic intervals originates from the development of the conamed biofacies in regressive parts of Vas’kino and Domodedovo cyclothems (Fig. 47). The above data characterize fusulinid assemblages from normal marine parts of cyclothems as a continu ous patchwork of benthic communities, where few

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persistent biofacies crystallized. They include softround Hemifusulina communities and staffellid communities inhabiting shoals. The transgressive phases of basin development were probably favorable for expansion of Beedeina and schubertellids during at least the Podol skian to Early Myachkovian time. The steadiest (least disturbed) fusulinid biotopes expressed in our dataset in increased taxonomic diversity and evenness attained during highstands in areas of sufficient seafloor oxy genation (lithofacies D5 and its vicinity). 4.12. Frailty of Fusulinid Biofacies and Data Quality Limitations Our conclusions on fusulinid distribution patterns corroborate observations made by previous workers (see Introduction). In particular, the majority of genera occur in a very wide range of facies, varying in abundance and steadiness, which is usually quite low, expressed in xavg ≤ δ and s < 1 (Figs. 34, 38; Appendices 1, 2). This pattern of largely random distribution and insufficient crystallization of sustainable fusulinid biofacies is also suggested by cluster analysis (Figs. 35–37, 39–41). Nonstaffellid fusulinids were probably tolerant to sed imentary environments within the whole facies range under study. Such frailty of biofacies groupings may be a result of stormprone seafloor regimes and geologi cally rapid fluctuations of the sea level (Kabanov et al., 2006; Kabanov and Baranova, 2007). As a result, benthic communities were kept in the pioneer state, that is, authigenic successions that would lead to hab itat differentiation under more stable conditions ceased at early stages of their development. The only example of welldefined fusulinid biofacies is the Hemifusulina biofacies (Fig. 47). This apparently largely chaotic pattern of fusulinid distribution may be influenced by several artificial and natural factors. The artificial factors include very dif ferent sample sizes for each lithofacies (from 5 to 85 thin sections: Figs. 34, 38) and contribution of thin sections from different stratigraphic levels within the Podolskian and Myachkovian datasets (Fig. 31). The differences in thin section area (from 9 to 36 cm2) seem to have a considerable effect on the abundance of rare and very large forms (more than 3 mm in diame ter); however, they did not influenced a lot the densi ties of frequent and smaller forms with the diameter less than onetenth of the linear size of the thin sec tion. We also believe that the indices of diversity H and domination d weighted on more frequent forms are only insignificantly biased. Of the natural factors, we should consider the concentration of fusulinid tests as a function of sedimentation rate. In particular, grain stones of lithofacies C1 are condensed deposits (lags) with much higher concentration of contemporaneous populations than in wackestones, calcimudstones, and

muddy tempestites of the D7–D6–D5–D4 lithofa cies range. This probably explains peaks of fusulinid density, diversity, and domination in the Myachkovian lithofacies C1 (Figs. 34, 38, 43, 44). Another natural factor is changes in facies preferences of fusulinids over time. Finally, the vague boundaries of fusulinid biofa cies must have been influenced by postmortem hydro dynamic dispersal of tests. CHAPTER 5. RELATIONSHIP OF GENERAL, FUSULINID, AND CONODONT BIOFACIES Among Carboniferous metazoans, the biofacies models are most thoroughly developed for conodonts. Conodont biofacies combined with sedimentological analysis work well to reconstruct depositional environ ments and relative distance from the shoreline approx imated by inferred degree of salinity and paleodepth fluctuations (Merrill, 1973; Heckel and Baesemann, 1975; Merrill and von Bitter, 1976, 1979; Driese et al., 1984; Davis and Webster, 1985; Morrow and Webster, 1991). In addition, there are general classifications of Phanerozoic sedimentary carbonates, having certain biofacies resolution in the studied sedimentary succes sion (Kabanov, 2009). 5.1. Benthic Carbonate Factories and General Carbonate Facies of the Phanerozoic Lees and Buller (1972; Lees, 1975) proposed a gen eral division of Recent sedimentary carbonates based on the composition of skeletal particles, that is, recog nized the most general biofacies. The shallowwater tropical carbonates were grouped into the chlorozoan association (from the green calcareous algae Chloro phyta and hermatypic corals Zoantharia), and cooler water carbonates known by that time outside the trop ical shallowwater areas were named foramol carbon ates based on foraminifers and mollusks, which are the master constituents of coolwater (moderately cold water) facies. An increasing number of general skele talgrain facies emerged in subsequent years, as it became clear that the terms “foramol” and “chloro zoan” are inadequate for principal facies groupings of remote geological past with their evolutionary distinc tions in the marine biota. James (1997) proposed to omit the names of taxa and introduced the replace ment name photozoan for the chlorozoan association, based on the leading role of phototrophic organisms and algal–animal symbioses. For foramol and other nonchlorozoan associations, James (1997) introduced the name heterozoan. In the heterozoan association, carbonate sediments are mostly composed of het erotroph skeletons; however, red coralline algae known for their broad tolerance range to cool waters and seafloor dimming are included as a typical com ponent. Halfar et al. (2004) suggested to use the name PALEONTOLOGICAL JOURNAL

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photozoan only with reference to the facies containing more than 20% of photozoan components; facies with less than 1% of photozoan components were classified as heterozoan, and facies with 1–20% of photozoan components were regarded as transitional hetero– photozoan. Schlager (2000, 2003, 2005), avoiding the names “photozoan” and “heterozoan,” recognized three principal benthic carbonate factories: (1) Tfac tory, i.e., the tropical shallowwater factory producing James’ photozoan facies; (2) Cfactory describing cool and coldwater sedimentary conditions of James’ heterozoan facies; and (3) Mfactory determined by the leading role of nonskeletal microbially induced and organomineral micrites (automicrites; Flügel, 2004; Pomar and Hallock, 2008). Typical accumula tion forms of M–carbonates are mudmounds (“agglutiherms” in Russian literature) that lack close modern analogues. Mudmounds became widespread in certain intervals of the Phanerozoic and Late Pre cambrian (Pratt, 1995). A comprehensive review of biotic and physicochemical processes interacting in the main carbonate factories is given by Pomar and Hallock (2008). In the Late Moscovian basin of the Moscow Synec lise, carbonates were accumulated within the range of T and C factories of W. Schlager. Fusulinids are essential components characterizing both photozoan and hetero zoan biofacies (Kabanov, 2009). Relationship of fusulinid and general biofacies is shown in Figs. 49 and 50. 5.2. Staffellid–Syphonean Biofacies The staffellid–syphonean biofacies (Kabanov, 2009) is centered within the D2–C1 lithofacies range and also partially spreads to D3, D4, D1, and BD lithofacies. Its indicators are the fragments or com plete in situ thalli of syphonean green algae of the fam ily Udoteaceae (phylloid algae: Wahlman, 2002; Flü gel, 2004), steady presence of staffellids, and develop ment of automicrite in the form of micritized grains, infills of microendolithic borings, micritic dense to clotted cements, and various peloids. Dasycladacean syphoneans are rare (at most 0.3–0.5 fragments/cm2) and occur in the shallowest water grainstones and packstones. Beresellean algae of the genera Dvinella and Beresella (presumably syphonocladaleans; Shuisky, 1987) are sometimes abundant. Podolskian shoal grainstones sometimes contain an admixture of ooids. In staffellid–syphonean facies, at least 5% of sedimentary grains are usually micritized. The number of staffellids varies in thin sections from 0.2 to 8 sec tions/cm2. The composition of the skeletal benthos is variable, but the diversity is generally high or very high and the extent of domination of particular taxa tends to be low. Apparently, this is the only biofacies hosting in situ colonial cerioid tetracorals, as exemplified by PALEONTOLOGICAL JOURNAL

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the classical “coral–foraminiferal beds” of the Korob cheevo Formation of the Moscow Region (Rauser Chernousova and Reitlinger, 1954; Makhlina et al., 2001b; Kabanov, 2003). The staffellid–syphonean biofacies is characterized by the Choristites brachiopod biofacies, which is defined by steady presence of the index genus (Kabanov, 2003; Kabanov et al., 2006). The sedimentary bedding is poorly preserved because of bioturbation, which is generally chaotic, with occa sional poorly ordered, sometimes “swirly” features (burrow infills?). Long (up to 1 m) subvertical and Vshaped thalassinoid burrows are sometimes seen (Kabanov, 2003). The staffellid–syphonean facies is in general photozoan; however, some packstones and wackestones with less than 20% of photozoan markers among allochems should be regarded as transitional heterophotozoan according to Halfar et al. (2004). The staffellid–syphonean biofacies is very similar to the Early Permian chloroforam carbonate association or facies of the Canadian Arctic and Svalbard (Beau champ, 1994; Beauchamp and Desrochers, 1997) but differ in the fewer dasycladaceans. It also seems rele vant to include the name of a certain foraminiferal group (the order Staffellida) in the biofacies name, because foraminifers in general implanted into the name of the chloroforam association characterize excessively broad range of facies and paleodepths. A special variety of staffellid–syphonean biofacies corresponds to lithofacies D3. This is a biostrome forming algal boundstones known from the Podol skian Substage of the Moscow Region and Pinega mapping area of the Arkhangelsk Region (biostromes with Ivanovia tenuissima: Ivanova, 1958; Il’khovsky, 1975). These biostromes are composed of thalli of udotean chlorophytes (Eugonophyllum, Ivanovia) and thick cementing automicrite. Algal biostromes are up to 2.5 m thick at Pinega and can likely be traced for tens and even hundreds of kilometers. These bound stones feature a relatively low diversity of macro and microfossils. In particular, bryozoans are absent, except for rare allochthonous fragments. The brachio pod assemblage can be characterized as an impover ished Choristites biofacies (Ivanova, 1958). Fusulinids are singular and include staffellids. Similar algal boundstones widely occur in the Pennsylvanian of North America, where they form prominent algal mounds (Wilson, 1980; Wahlman, 2002; Samankassou and West, 2002). The Myachkovian beds show only small lenses of these boundstones associated with lithofacies D2 and C1. 5.3. Extended Bryonoderm Biofacies This biofacies is closely similar to the extended (including foraminifers) bryonoderm skeletal associa tion of the Upper Carboniferous–Lower Permian of

1m

Podolsian Gory

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Proportion of micritized sedimentary particles

Sea

Benthic calcareous algae (sections/cm2)

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0.3 Parastaffelloides 0.3 1 Reitlingerina

0.3 1 Hemifusulina 10

0.3 1 Fusulinella 10 0.3 1 Fusulina

10 0.3 1 Ozawainella

0.3 Oncoids, with partici 1 pation of Claracrusta 0.3 Eostaffella 1 0.3 1 Schubertellidae

0.3 Asphaltinella 0.3 1 Ortonella

Traces of Zoophycos Micritized grains Brachiopod Choristites genera–biofacies Meekelle indices 0.3 Dasycladacean algae 0.3 1 Phylloid algae 10 0.3 Anthracoporellopsis 1 0.3 Stachelaceae 1 0.3 Donezella 1

Clay Calcimudstones Wackestones Packstones Grainstones

Relative sea level fluctuation

Lithologic column

Horizon Formation/cyclothem Member

Benthic calcareos algae

Fusulinid biofacies

>60% 25–60% 5–25%