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1

Revised holostratigraphy of the Tithonian-Berriasian transition at Tré Maroua (Le Saix, Hautes-Alpes, SE France): study of a rejected Berriasian GSSP candidate

Granier Bruno R.C., Benzaggagh Mohamed, Ferry Serge

Volumina Jurassica

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2023

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Vol. 21

1--18

EN

The study of the Tithonian and lower Berriasian succession of Le Saix (Hautes-Alpes, France) has made it possible to better characterize the lithological succession at a former Berriasian GSSP candidate, its set of microfacies, the stratigraphic ranges of the main groups of marine plankton and therefore the calpionellid and saccocomid biozonations. On the lithological level, the Tithonian strata are characterized by thick-bedded breccias representing debris flows and related calciturbidites, whereas the Berriasian strata are typically white limestones. The lower part of the Berriasian is comprised of scattered intercalations of thin-bedded breccias and calciturbitides (including cryptic mud calciturbidites). In thin sections, the white limestones display mud- to wackestone textures and their allochems are mostly tiny bioclasts (e.g., radiolarians, calpionellids, saccocomids). Calciturbidites have wacke- to grainstone textures and their allochems are mostly pseudointraclasts and extraclasts, comprising various bioclasts and some ooids. Mud turbidites are made of micrograin-stones some yielding almost exclusively well-sorted calpionellids, which were previously erroneously interpreted as the signature of “explosions” or “blooms” of Calpionella alpina. Breccias are mostly lithoclastic floatstones with a matrix similar to that of the calciturbid- ites. Their lithoclasts are either extraclasts sensu stricto, i.e., material derived from updip shallow-water areas, or pseudointraclasts representing reworked subautochthonous material, i.e., mud- and wackestone lithoclasts with radiolarians, saccocomids and/or calpionellids. Radiolarians are common over the whole studied interval. Saccocomids are part of the dominating biota reported from the lower and lower upper Tithonian interval whereas calpionellids replace them in the uppermost Tithonian to lower Berriasian interval. Minor plank- tonic groups comprise calcareous dinoflagellates and Globochaete alpina; Iranopsis nov. group is also present. Intervals with saccocomid sections characteristic of zones 4-5 and zone 6 are respectively ascribed here to the lower Tithonian (4-5) and the lower upper Tithonian (6). The biozonation of the calpionellid group sensu lato allows identification of i) the Boneti Subzone of the chitinoidellids, ii) the Cras- sicollaria Zone, more specifically its Tintinnopsella-Intermedia (A1), Intermedia-Alpina (A2) and Brevis-Massutiniana (A3) subzones, and iii) the Alpina Zone, with its Alpina-Parvula (B1) and its Alpina-Remaniella (B2) subzones. On the basis of biostratigraphical and sedimentological data, most zonal boundaries prove to be hiatal, located at the erosional base of breccia or turbidite layers whereas the Tithonian/Berriasian stage boundary appears to be located at a strike-slip fault plane in the Tré Maroua section.

2

Deep-sea trace fossils from the Numidian Formation (Upper Oligocene–Lower Miocene) in the Ouarsenis Mountains, northwestern Algeria

Menzoul Bouabdellah, Uchman Alfred, Adaci Mohamed, Bensalah Mustapha

Geological Quarterly

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2022

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Vol. 66, No. 2

art. no. 12

EN

Trace fossils and lithofacies have been studied for the first time in the Numidian Formation (Upper Oligocene–Lower Miocene) of the Ouarsenis Mountains in Algeria to interpret their depositional environment. Twenty-two ichnogenera have been recognized in eight lithofacies of three main facies associations in four representative sections. Distribution of the trace fossils is dependent on the facies. Most trace fossils are dominated by post-depositional forms (62%) and occur in fine-grained, thin-bedded sandstones of facies F4. They belong to the Ophiomorpha rudis, Paleodictyon and the Nereites ichnosubfacies of the Nereites ichnofacies. The O. rudis ichnosubfacies is recorded in 1) medium- to very thick-bedded sandstones of the facies association FA1, interbedded with thinner sandstone beds of the facies F2 and F4 in the upper unit of the sections studied, which were deposited in channel fill and levee-overbank environments, and in 2) medium- to thin-bedded sandstones of the facies association FA2 in the lower unit of the Kef Maiz and the Ain Ghanem sections, which were deposited in isolated narrow channels within the mud-dominated part of the depositional system and occasionally fed with turbiditic sand. The Paleodictyon ichnosubfacies occurs in thin- to medium-bedded sandstones (FA2) of the lower units in the Ain Ghanem and Kef Maiz sections and the lowest part of the upper unit of the Kef Maiz section, which were deposited in channel margin or foremost channel-to-levee-overbank areas. The Nereites ichnosubfacies is recorded in thin-bedded sandstones (FA2), which were deposited in crevasse-splays or small lobes on a basin floor invaded occasionally by turbidites against a background of pelagic and hemipelagic sedimentation.

3

Contrasting styles of siliciclastic flysch sedimentation in the Upper Cretaceous of the Silesian Unit, Outer Western Carpathians : sedimentology and genetic implications

Strzeboński Piotr

Annales Societatis Geologorum Poloniae

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2022

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Vol. 92, No. 2

159--180

EN

This study reports on a new set of sedimentological data and related interpretations of the Santonian–Campanian siliciclastic deposits in the Western Flysch Carpathians based on natural outcrops in the uppermost Godula Formation and lowermost Istebna Formation. The rationale was to confront the characteristics of this flysch succession with current controversies and state of knowledge on deep-water clastic sedimentation. The sedimentological analysis of the field data allowed for multi-scale synthetic classifications of the depositional components in the investigated flysch. The hierarchical and practical nature of the suggested classification schemes allows for their application to similar deposits in other regions. The siliciclastic deposits are products of gravity-driven terrigenous sediment redeposition via submarine slumps, debris flows, and turbidity currents. Sediment reworking by tractional bottom currents is considered as an accompanying factor. Point-sourced turbiditic fan lobe fringes from the submarine piedmont ramp and linearly supplied debritic covers along the slope apron are proposed as dominant. The innovative linking between the textural-structural descriptive features of the deposits and the critical determinants of specific sediment gravity-flow processes and architectural elements of the deepwater clastic depositional systems is a significant contribution to this research field.

4

Interaction between turbidity currents and a contour current – a rare example from the Ordovician of Shaanxi province, China

Li Hua, van Loon A. J. (Tom), He Youbin

Geologos

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2019

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Vol. 25, No. 1

15--30

EN

The silty top parts of graded turbidites of the Late Ordovician Pingliang Formation, which accumulated along the southern margin of the Ordos Basin (central China), have been reworked by contour currents. The reworking of the turbidites can be proven on the basis of paleocurrent directions in individual layers: the ripple-cross-bedded sandy divisions of some turbidites show transport directions consistently into the downslope direction (consistent with the direction of other gravity flows), but in the upper, silty fine-grained division they show another direction, viz. alongslope (consistent with the direction that a contour current must have taken at the same time). Both directions are roughly perpendicular to each other. Moreover, the sediment of the reworked turbidites is better sorted and has better rounded grains than the non-reworked turbidites. Although such type of reworking is well known from modern deep-sea environments, this has rarely been found before in ancient deep-sea deposits. The reworking could take place because the upper divisions of the turbidites involved are silty and consequently relatively easily erodible, while the contour current had locally a relatively high velocity – and consequently a relatively large erosional capability – because of confinement within a relatively narrow trough.

5

Sedimentary response to tectonic uplift of the Dukla basin margin recorded at Skrzydlna – the Menilite Beds (Oligocene), Outer Carpathians, S Poland

Siemińska A., Starzec K., Godlewski P., Wendorff M.

Geology, Geophysics and Environment

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2018

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Vol. 44, no. 2

231--244

EN

The Menilite Beds (Oligocene of Polish Flysch Carpathians) at Skrzydlna crops out in a structurally complex zone of the Fore-Magura Unit, which is tectonically overridden by Magura Nappe thrust form the S. The exposed sedimentary suite, representing the Dukla Basin, consists of fine-grained, well organised strata deposited in a low-energy, deep marine basin, which are abruptly overlain by poorly organised, coarse sandy conglomerate that forms a Mass Transport Deposit (MTD) complex. The MTD contains large boulders of extrabasinal rocks, massive sandstone beds with intrabasinal mudstone clasts, and slump sheets of sandstones. Above rests a fining- upwards sequence of sandstone beds interlayered with mudstones. The fine-grained facies reappear above to terminate the exposed succession. Erosional contacts and rapid facies changes, both vertical and lateral, are characteristic for the MTD unit. The sandstone-mudstone unit above contains laterally migrating erosional channels filled with massive sandy conglomerate in the lower part. Turbidites of varying density and completeness of internal structures that occur above are accompanied by an association of mixed facies including large-scale dune cross-bedding. Mineralogically, the sandstones are quartz arenites, sub-lithic arenites and wackes. Calcarenite grains – bioclasts, micrite and marl occur in substantial proportions only in the uppermost part of the succession. The point-counting data plotted on Qm-F-Lt diagram are clustered within the recycled fields: quartzose and transitional. Mineralogical maturity of the sandstones has the tendency to decrease from the sub-MTD strata upwards via the MTD unit to the lower part of the sandstone-mudstone complex; then it increases to the youngest sandstone beds with carbonate grains. These tendencies, associated with sedimentary features of the succession, reflect rapid uplift, emergence and progressive erosion of the terrigenous detritus source area, followed by tectonic stabilisation reflected by the appearance of the “carbonate factory”.

6

Lower Oligocene Menilite Beds, Polish Outer Carpathians: supposed deep-sea flysch locally reinterpreted as shelfal, based on new sedimentological, micropalaeontological and organic-geochemical data

Dziadzio P. S., Matyasik I., Garecka M., Szydło A.

Prace Naukowe Instytutu Nafty i Gazu

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2016

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nr 213

1--120

EN

The Menilite Beds form a widespread lower Oligocene marker succession in various nappes along the Outer Carpathians in the Slovak Republic, Poland, Ukraine, Romania and the Pannonian Basin System, long analysed in detail, like other lithological divisions in the Carpathians. Although the past 80 years of regional research gave inconsistent bathymetric interpretations, the vast majority of Carpathian geologists insist that all the Jurassic to Miocene deposits are of deep-water origin. Intuitively, however, any evolving array of tectonically active thrust wedge-top basins is likely to include many transient zones of shallow-water sedimentation whose deposits, if not cannibalized by erosion, might locally be preserved within the ultimate nappe stack. This hypothesis is postulated here for the (A) Magdalena Sandstone Member of the Menilite Beds in the Silesian Nappe, and (B) Magura Beds in the adjacent/suprajacent Magura Nappe. An early Oligocene age for both units is confirmed here by micropalaeontology. Measured Section A (Gorlice, Sękówka River) in the Silesian Nappe, was deposited on the northern side of an interpreted tectonic palaeo-highland, the Silesian Cordillera. Section A exposes about 180 m of the Menilite Beds and reinterpreted here (see also [30]) as three shallow-water retrogradational parasequences bounded by marine flooding surfaces, recording an overall tectonically-forced regression, previously interpreted as deep-sea deposits.Measured Section B (Ropica Górna, Sękówka River), of the Magura Nappe (Siary Zone), is likewise interpreted here is shallow-water deposits. Both the environment and the early Oligocene age interpreted here conflict with many previous publications. Palaeogeoraphically, Section B was deposited on the southern flank of the Silesian Cordillera. About 80 m of the Magura Beds are exposed in Section B, part of a ca. 2 km-thick succession. Both sections are thought to have accumulated on a tectonically-steepened narrow shelf. The shelf on the southern flank of the Silesian Cordillera was tectonically active, of stair type, dominated by an interpreted coarse-grained shelf-margin delta. The shelf on the northern flank is interpreted as an accommodation-driven, shallow-water deltaic system. The presented work of a detailed sedimentological research programme showing a different point of view on the sedimentation of the Menilite Beds (see also [29, 30]), which are the main hydrocarbon source rock in the Carpathians and are still poorly understood. This work emphasises the global importance of the interpretation of flysch palaeobathymetry arising from sedimentologists' increasing ability to recognise combined-flow sedimentary structures in flysch. This research is a step towards understanding the facies distributions and sedimentary environments of the Menilite Beds throughout the Carpathians.

PL

Głównym zagadnieniem omawianym w niniejszej pracy jest wykształcenie facjalne oraz środowisko sedymentacji warstw menilitowych. Stanowią one regionalny marker w sukcesji utworów dolnego oligocenu występujący w różnych płaszczowinach zachodnich i wschodnich Karpat Zewnętrznych na terenie Słowacji, Polski, Ukrainy, Rumunii oraz w obszarze basenu panońskiego. Od dawna były one poddawane, tak jak i inne wydzielenia litostratygraficzne w Karpatach, szczegółowym badaniom. Jednak w ciągu ostatnich 80 lat badań prowadzonych na poziomie regionalnym nie uzyskano ich spójnej interpretacji batymetrycznej. Większość geologów badających Karpaty twierdzi, że utwory budujące Karpaty w okresie od jury do miocenu mają głębokowodną genezę. Wydaje się jednak bardzo prawdopodobne, że lokalnie – na powstających w wyniku tektonicznej ewolucji wewnątrzbasenowych wyniesieniach (zwanych również kordylierami) – mogło dochodzić do rozwoju stref z płytkowodną sedymentacją, gdy nie uległy one procesowi kanibalizacji w wyniku erozji. Dzięki temu utwory takie mogły również zachować się w obrębie struktur płaszczowinowych. Ta koncepcja poparta badaniami sedymentologicznymi, biostratygraficznymi i geochemicznymi znajduje uzasadnienie w przypadku warstw menilitowych z piaskowcami magdaleńskimi występującymi w obrębie płaszczowiny śląskiej oraz w obrębie warstw magurskich płaszczowiny magurskiej. Obie jednostki obecnie znajdują się w bliskim sąsiedztwie i w obu przypadkach badane utwory z ich obrębu są wieku dolnooligoceńskiego. Sukcesja warstw menilitowych odsłaniająca się w korycie rzeki Sękówki w Gorlicach (profil A) z obrębu płaszczowiny śląskiej ma udokumentowaną, około 180-metrową miąższość. Składa się ona z trzech retrogradacyjnych parasekwencji ograniczonych powierzchniami zalewu morskiego. Została zinterpretowana jako zestaw płytkomorskich parasekwencji powstałych w warunkach wymuszonej regresji [por. 30], a nie (jak to dotychczas było przyjmowane) jako osad głębokomorskich turbidytów. Z punktu widzenia paleogeografii profil A powstał po północnej stronie tzw. kordyliery śląskiej.Profil B (odsłaniający się w korycie rzeki Sękówki w Ropicy Górnej) należy do płaszczowiny magurskiej (strefy Siar). Zinterpretowana zmienność warunków sedymentacji wskazuje na powstanie tych utworów również w obrębie płytkowodnego systemu depozycji. Zarówno zinterpretowane środowisko sedymentacji, jak i wiek tych utworów, określony na dolny oligocen są inne niż te prezentowane w wielu poprzednich pracach. Paleogeograficznie profil B został zdeponowany po południowej stronie kordyliery śląskiej. Ma on około 80 m miąższości i stanowi dolną część mierzącej około 2000 m grubości sukcesji warstw magurskich. Oba profile zostały zinterpretowane jako powstałe na tektonicznie kontrolowanych wąskich szelfach. Szelf po południowej stronie kordyliery śląskiej był bardzo aktywny tektonicznie, miał charakter schodowy i był zdominowany prawdopodobnie sedymentacją, jaka mogła mieć miejsce w systemie gruboklastycznej delty skraju szelfu. Szelf po północnej stronie został natomiast zinterpretowany jako szelf napędzany akomodacją, na którym rozwijał się płytkowodny system deltowy. Zaprezentowane wyniki badań są kompleksowym zbiorem szczegółowych badań sedymentologicznych pokazujących odmienny punkt widzenia na sedymentację i genezę warstw menilitowych [por. 29, 30], które są główną skałą macierzystą dla węglowodorów w Karpatach, a które są wciąż słabo poznane.Niniejsza praca ma znaczenie dla nowej, choć wcześniej sygnalizowanej w kilku publikacjach, interpretacji utworów tzw. fliszu i jego paleobatymetrii oraz pokazuje szereg nierozpoznanych dotychczas struktur sedymentacyjnych. Stanowi ona krok w kierunku zrozumienia rozkładu facji i środowisk sedymentacji warstw menilitowych w obrębie Karpat.

7

The middle/late Eocene transition in the Eastern Carpathians (Romania) based on foraminifera and calcareous nannofossil assemblages

Bindiu R., Filipescu S., Balc R., Cocis L., Gligor D.

Geological Quarterly

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2016

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Vol. 60, No. 1

38--55

EN

Foraminiferal and calcareous nannofossil assemblages from the Eastern Carpathians (northern part of the Tarcău Nappe, Romania) were documented and correlated in order to reconstruct the palaeonvironmental settings and provide a biostratigraphic framework of the Plopu Formation. The benthic foraminiferal assemblages are dominated by flysch-type agglutinated taxa, suggesting a bathyal palaeodepth with frequent oscillations of the carbon compensation depth. The agglutinated foraminifera morphogroup analyses suggest different levels of organic matter influx and oxygenation. Both the foraminifera and calcareous nannofossil assemblages suggest a shift between the warm mid Eocene to the cooler late Eocene climate. Biostratigraphic data based on calcareous nannofossils (NP15–NP19/NNTe8–NNTe12 biozones) helped to establish the age of the formation. Four assemblages of benthic agglutinated foraminifera (Psammosiphonella cylindrica – Nothia excelsa; Paratrochamminoides spp. – Trochamminoides spp.; Karrerulina spp.– Reticulophragmium amplectens; Spiroplectammina spectabilis) correlated with calcareous nannofossil bioevents supported the placement of the mid to late Eocene transition within the Plopu Formation.

8

Age, internal stratigraphic architecture and structural style of the Oligocene–Miocene Numidian Formation of northern Tunisia

Riahi S., Soussi M., Ben-Ismail-Lattrache K.

Annales Societatis Geologorum Poloniae

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2015

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Vol. 85, No. 2

345--370

EN

The stratigraphy of the Numidian Formation of northern Tunisia and its internal organization are updated. Planktonic foraminifera point to a mainly Oligocene–Early Miocene age of this formation in the majority of the sections studied. Some key lithological horizons are recognized within the early Miocene succession, allowing lateral correlation between the outcrops of the Mogod and Kroumirie mountains. These include: (1) a conglomeratic interval, up to 1–2 m thick and rich in reworked glauconitic boulders, limestone fragments of the Tellian (Eocene) and pectinid bivalves; and (2) a relatively continuous glauconitic level. In the new stratigraphic scheme, the Zouza, Ben Metir and Sejnene sections represent the entire Numidian Formation. A lower unit (200–700 m thick), highly pelitic with subordinate sandstone beds was distinguished, overlain by an upper unit which is sandier, especially in its uppermost part (1,000–1,500 m thick). In the present study, these have been stratigraphically dated as Oligocene–Early Miocene p.p. (Rupelian–Chattian; P19–P21 zones) to Aquitanian (N4 Zone) and Miocene (Aquitanian–early Burdigalian; N4–N5 zones), respectively. In the areas studied, the sandy succession assigned to the Kroumirie Member begins with a sandstone unit with an erosional base or a major discontinuity, locally marked by conglomerates made up of various reworked components. It rests generally on a thick shale unit that characterises the upper part of the Zouza Member. The thinner, uppermost succession of the Numidian Formation represents the Babouch Member, dated as Burdigalian (N6–N7 zones). Within the framework of the new proposal, the total stratigraphic thickness of the Numidian Formation in northern Tunisia does not exceed 2,200–2,600 m. Internally, the Numidian Formation is transected by the Intra-Numidian Thrust and back-thrust faults, associated with faulted folds that are recognized in outcrop on different scales and in seismic sections. Along these thrust and/or reverse faults, the middle to upper Eocene deposits have undergone uplift and are exposed at the surface (e.g., Dowar Larmel in Meloula-Tabarka, Gaâret Sejnene and Sidi M’chreg sections).

9

Local sediment sources and palaeoflow directions in Upper Miocene turbidites of the Pannonian Basin System (Croatian part), based on mapping of reservoir properties

Novak-Zelenika K., Velić J., Malvić T.

Geological Quarterly

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2013

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Vol. 57, No. 1

17–-30

EN

The source of the clastic sediments in the Croatian part of the Pannonian Basin System (CPBS) during the Late Pannonian and Early Pontian was the Eastern Alps. Clastic sediments were redeposited several times before they reached the Sava Depression. The depositional environment and sediment transport mechanisms have been subject to detailed analysis described in many publications, and this study builds on previous research. We have carried out geostatistical mapping of selected Upper Pannonian and Lower Pontian reservoir variables of the Kloštar Field, located to the west of the Moslavačka gora Mt. (Croatia). This has shown that the Moslavačka gora Mt. was a secondary, local source of sediment, in contrast to the previous interpretation of a single, distant clastic source (Eastern Alps) for the CPBS during the Late Miocene. As the mineralogical composition of the Moslavačka gora Mt. and the Eastern Alps is very similar, the dominant direction of turbidity currents obtained by sequential indicator simulations are used to suggest that a modest amount of detritus was eroded from the Moslavačka gora Mt. and mixed with detritus sourced from the Eastern Alps.

10

Review of Miocene shallow marine and lacustrine depositional environments in Northern Croatia

Malvić T.

Geological Quarterly

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2012

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Vol. 56, No 3

493--504

EN

The Neogene and Quaternary depositional and structural characteristics of the southwestern Croatian Pannonian Basin System (CPBS) are unique within the Pannonian Basin System. Due to its position at the basin margin, the area was covered by shallow and partially isolated parts of the Pannonian Sea in the Badenian (Middle Miocene). Later, in the Pannonian and Pontian ages, the area contained several brackish lakes, the largest being Sava Lake and Drava Lake. Tectonic events, sedimentation and depositional mechanisms occurring during the Neogene in the CPBS have revealed that those areas can be considered as former shallow seas or lakes dominated by clastic sedimentation. Marine coarse-grained clastic sedimentation took place during the Badenian, with local sources of material and numerous alluvial fans developed during the first transtensional phase. In the Pannonian and Pontian (Late Miocene), sediments were deposited by turbidity currents from a single, distal material source located in the Eastern Alps during the second transtensional tectonic phase.

11

Middle Miocene deposits in Carpathian Foredeep : facies analysis and implications for hydrocarbon reservoir prospecting

Lis P., Wysocka A.

Annales Societatis Geologorum Poloniae

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2012

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Vol. 82, No. 3

239–-253

EN

This sedimentological study was based on well cores from the Polish and Ukrainian parts of the Carpa- thian Foredeep. It revealed general heterogeneity of facies in the middle Miocene of the sedimentary succession in the basin. Fourteen sedimentary facies were distinguished and their origin was interpreted: massive, non-graded sandstones; normal-graded, massive sandstones, with and without a stratified uppermost part; hydroplastically deformed sandstones; planar-parallel-stratified sandstones; trough-cross-stratified sandstones; ripple-cross-lami- nated sandstones; heterolithic deposits, composed of thinly interlayered sandstone and mudstone; massive and laminated mudstones; and basal gypsum/anhydrite evaporites, often intercalated with mudstone. Four main modalities of vertical facies organization were recognized and attributed to the following environments: (1) the mid-late Badenian, shoal-water, evaporitic environment that preceded the latest Badenian–early Sarmatian, main phase of foredeep development; (2) a littoral, tidal environment of the inner parts of storm-influenced, coastal bays and tidal flats or possibly spit-sheltered lagoons; (3) a wave-dominated, littoral, sandy environment, considered to be shoreface, extended by waves, in front of advancing deltas; and (4) a neritic to subneritic, muddy, offshore slope, characterized by frequent incursions of tempestite and turbidite sand. The study contributed to a better understanding of the mid-Miocene depositional systems in the basin, with significant implications for ongoing hydrocarbon exploration. Interpretations of the origins of potential reservoir sandstones provided important information on their possible stratigraphic distribution in the basin fill. The potential, economic importance of stratigraphic hydrocarbon traps underscored the urgent need for a full-scale facies analysis and fully cored wells in strategic parts of the basin.

12

Ichnocoenoses in the Oligocene to Miocene foredeep basins (Northern Apennines, central Italy) and their relation to turbidite deposition

Monaco P., Checconi A., Milighetti M.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

53-70

EN

Analysis of trace fossil abundance and diversity in the Oligocene to Miocene foredeep and piggyback basins of the Tuscan-Romagna-Umbrian Apennines allows us to recognize five ichnocoenoses. The deposits reflect sedimentary environments from slope to basin plain, whose sedimentation was directly controlled by synsedimentary tectonics: attached fan lobes and channels, lobe- and channel-fringes, overbank-fringes of intrabasinal highs, distal detached lobes of basin plain and slope-proximal interfans. The graphoglyptid: non-graphoglyptid ratio has been considered as the chief factor in the study of ichnologic material from Falterona-Cervarola-Trasimeno, Marnosoarenacea and Marne di Vicchio-Verghereto stratigraphic units. The study shows that there is an increase in ichnodiversity and ichnodensity of graphoglyptids, which are typical mainly in detached lobes of basin plain and overbank-levee deposits whose background ichnofauna also shows better preservation.

13

Eocene graphoglyptids from shallow-marine, highenergy, organic-rich, and bioturbated turbidites, Fuegian Andes, Argentina

Olivero E., Lopez C. M., Torres Carbonell P., Malumian N.

Acta Geologica Polonica

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2010

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Vol. 60, no. 1

77-91

EN

Graphoglyptids are diagnostic ichnofossils of the Paleodictyon ichnosubfacies (Nereites ichnofacies), which is well represented in deep-marine Mesozoic.Cenozoic thin-bedded turbidites. However, unusual shallow-water records of Mesozoic-Cenozoic Paleodictyon and particular preservational restrictions of graphoglyptid burrows introduce the question of whether graphoglyptids are reliable bathymetric indicators. We document and discuss another unusual graphoglyptid association preserved in shallow-marine, high-energy, organic-rich, and bioturbated turbidites of leveed channels in the upper middle Eocene CCa member, Cerro Colorado Formation, Fuegian Andes. The member includes the facies associations: 1) mudstones, 2) interbedded mudstones and thin-bedded Tbc turbidites, and 3) thick-bedded sandstones andmudstones. Facies association 3), interpreted as channel deposits, records at least three horizons with Desmograpton, Glockerichnus, Helicolithus, Helminthorhaphe, Megagrapton, Paleodictyon and Urohelminthoida. Associated beds are lenticular, channeled sandstone turbidites with marked basal erosion surfaces and variable proportions of interbedded mudstone-sandstone with high content of plant debris. Trace fossils in the channeled sandstones are dominated by Ophiomorpha rudis and O. annulata; mudstones within the thick-bedded mudstone-sandstone beds bear Nereites, Phycosiphon, Zoophycos and Paradictyodora, with subordinate Schaubcylindrichnus, Tasselia and Scolicia. The unusual preservation of limited graphoglyptid-bearing beds within a highly energetic and bioturbated interval seems to support the concept that preservational restrictions on graphoglyptid burrows could be locally more important than bathymetric constraints.

14

Trace fossils from Silurian and Devonian turbidites of the Chauvay area, southern Tien Shan, Kyrgyzstan

Warchoł M., Leszczyński S.

Annales Societatis Geologorum Poloniae

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2009

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Vol. 79, No 1

1-11

EN

The siliciclastic turbidite successions (Pul’gon and Dzhidala Formations) that crop out in the eastern part of the Chauvay River valley, are marked on geological maps as a belt of terrigenous deposits of Silurian-Devonian age. They resemble deposits of overbank areas and depositional lobes of deep sea fans, and display common trace fossils particularly on lower surfaces of sandstone beds. Sixteen ichnotaxa representing four morphological groups have been distinguished. The trace fossil assemblages suggest their affiliation to the Nereites ichnofacies. Various branched, preturbidite forms predominate in both examined units, although the assemblages of individual units differ slightly in composition. In the Pulg’on Formation, small, densely distributed burrows commonly occur on lower surfaces of sandstone beds. Shallow burrowing depth together with relatively low diversity trace fossil assemblages indicate lowered oxygenation of the sea floor.

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Trace fossil Artichnus pholeoides igen. nov. isp. nov. in Eocene turbidites, Polish Carpathians : possible ascription to holothurians

Zhang G., Uchman A., Chodyń R., Bromley R.

Acta Geologica Polonica

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2008

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Vol. 58, no. 1

75-86

EN

A hitherto unknown trace fossil was found in some abundance in turbidites of the Polish Outer Carpathians. The occurrence is within the Hieroglyphic Beds of the Silesian Nappe, within the Szczyrzyc Synclinorium, of Middle Eocene age. The trace fossil is a wide, J-shaped structure having a narrow, upward tapering shaft as a connection to the seafloor. The distal end also tapers, to a blind termination. The burrow lumen is surrounded by an irregular spreite structure. The trace fossil is compared with the work of burrowing holothurians, which show some comparative features that suggest a tracemaker belonging to the Apodida.

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The contribution of Stanisław Dżułyński to flysch sedimentology: A 'Western' perspective

Kelling G., Walton E. K., Simpson F.

Annales Societatis Geologorum Poloniae

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2007

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Vol. 77, No 2

93-103

EN

Abstract: In his ground-breaking research on the sedimentary structures of turbidites, Stanisław Dżułyński demonstrated and took to new levels of accomplishment the defining attributes of the Kraków School of flysch sedimentology established by Marian Książkiewicz at the Jagiellonian University. These attributes included a meticulous approach to fieldwork, the ability to recognize the scalar and vector relationships of diverse sedi- mentary features, a working knowledge of several languages, a capacity to describe systematically structures that had previously received scant attention in the world literature of geology, and innovation in the transfer of scientific knowledge. Dżułyński also added elements that were distinctively his own: a highly inventive approach to the replication of turbidite sedimentary structures in laboratory flumes, an openness to new ideas, boundless enthusiasm for his chosen field, and an exuberantly outgoing personality. In spite of worldwide recognition for his numerous and wide-ranging achievements in geology, he viewed himself first and foremost as one of the senior students of Marian Książkiewicz. In this role, Dżułyński utilised every opportunity to present with great insight and objectivity the work of the Kraków School, enthusiastically shared his extensive knowledge of sedimentology with experienced colleagues and new acquaintances alike and, in particular, gave generous encouragement to young researchers.

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Lacustrine trace fossils and environmental conditions in the Early Miocene Ermenek Basin, southern Turkey

Uchman A., Nemec W., Ilgar A., Messina C.

Annales Societatis Geologorum Poloniae

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2007

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Vol. 77, No 2

123-139

EN

The Early Miocene lacustrine succession of the Ermenek Basin, an intramontane graben in southern Anatolia, consists of hemipelagic, variably calcareous mudstones and pelagic marlstones densely interspersed with tempestite sandstone sheets, subordinate turbidite sandstone sheets and sporadic layers of evaporitic limestone. The marly lake was hydrologically closed and mainly no deeper than 10 m, with the mean fairweather wave base at 1.5 m and storm wave base around 5 m. The deposits abound in trace fossils, including Vagorichnus cf. anyao (its second recognized occurrence), endichnial ferruginous ribbons, large tubular structures, oblique cylinders, small discontinuous ridges, undulating ridges, planar wall structures and a range of other bioturbational features. The tempestites and turbidites show both pre-and post-event trace fossils, with recognizable mixed and transitional layers similar as reported from marine tempestites and turbidites. The trace fossils constitute an impoverished Mermia ichnofacies indicating a considerable environmental stress. The lake salinity fluctuated, and the stress factor is attributed to the extreme environmental conditions (increased salinity and unusual water chemistry) caused by episodes of brackishness due to decreases in rainfall and increases in evaporation. Freshwater conditions are indicated by benthic ostracods and mollusc shells in offshore mudstones and by gastropod shells in coastal coal deposits, whereas marly layers contain only the ostracod species Miocyprideis glabra asulcata, implying mesohaline to polyhaline conditions.

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Comparison of deep-water agglutinated foraminifera from the hemipelagic variegated shales (Lower Turonian-Lower Santonian) and turbiditic Godula beds (Upper Santonian-Campanian) in the Lanckorona-Wadowice area (Silesian Unit, Outer Carpathians, Poland)

Lemańska A.

Studia Geologica Polonica

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2005

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Vol. 124

259-272

EN

Deep-water agglutinated foraminifera (DWAF) have been studied from variegated shales and Godula beds exposed in the vicinity of Kalwaria Zebrzydowska (Silesian Nappe, Outer Carpa- thians, Poland). Following the standard foraminiferal zonation scheme of Geroch & Nowak (1984), the studied variegated shales can be correlated with the Uvigerinammina jankoi Zone (Lower Turonian-Lower Santonian). The Godula beds can be correlated to the Caudammina gigantea Zone (Upper Santonian-Campanian). Foraminiferal assemblages from the variegated shales are dominated by infaunal and semi-infaunal forms. Their occurrence suggests aerobic bottom water conditions associated with low organic matter availability during the deposition of this unit. Such conditions are presumably related to slow sedimentation rate in low energy, well-oxygenated and oligotrophic bottom environment. In contrast, foraminiferal assemblages from the Godula beds are dominated by epifaunal forms, which collected food from the sediment/water interface. It may suggest that sedimentation took place under relatively higher energy conditions with a higher organic matter flux.

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Trace fossils in the Cretaceous-Eocene flysch of the Sinop-Boyabat Basin, Central Pontides, Turkey

Uchman A., Janbu N. E., Nemec W.

Annales Societatis Geologorum Poloniae

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2004

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Vol. 74, No 2

197--235

EN

Sixty six ichnotaxa have been recognized in Barremian-Lutetian deep-marine deposits of the Sinop- Boyabat Basin, north-central Turkey, which evolved from a backarc rift into a retroarc foreland, with two episodes of major shallowing. The blackish-grey shales of the Çađlayan Fm (Barremian-Cenomanian) contain low- diversity traces fossils of mobile sediment feeders influenced by low oxygenation. One of the oldest occurrences of Scolicia indicates early adaptation to burrowing in organic-rich mud. The "normal" flysch of the Coniacian- Campanian Yemişliçay Fm bears a low-diversity Nereites ichnofacies influenced by volcanic activity. The Maastrichtian-Late Palaeocene carbonate flysch of the Akveren Fm contains a Nereites ichnofacies of moderate diversity, which is impoverished in the uppermost part, where tempestites indicate marked shallowing. The overlying variegated muddy flysch of the Atbaşý Fm (latest Palaeocene-earliest Eocene) bears an impoverished Nereites ichnofacies, which is attributed to oligotrophy and reduced preservation potential. The sand-rich silici-clastic flysch of the Kusuri Fm (Early-Middle Eocene) bears a high-diversity Nereites ichnofacies, except for the topmost part, where tempestites and littoral bioclastic limestone reflect rapid shallowing due to the tectonic closure of the basin. The turbiditic channel-fill and proximal lobe facies show a reduced trace-fossil diversity, but abundant Ophiomorpha , which is typical of the Ophiomorpha rudis sub-ichnofacies of the Nereites ichnofacies. The high abundance of Ophiomorpha in the Kusuri Fm and its low abundance in the Akveren Fm are related to plant detritus supply. The Kusuri turbiditic system was fed by a large delta, supplying rich plant detritus, whereas the Akveren system was fed by a carbonate ramp that supplied little or no such material. The extension of the Nereites ichnofacies into the tempestite-bearing neritic deposits at the top of both the Akveren and Kusuri formations indicates the capacity of the deep-water ichnofauna to survive in a rapidly-shoaling restricted basin. Only the topmost shoreface sandstones of the Akveren Fm show sporadic Ophiomorpha ? nodosa, a typical shallow-marine trace fossil.

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Geotectonic significance of Carboniferous deposits NW of the Holy Cross Mts. (central Poland)

Jaworowski K.

Geological Quarterly

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2002

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Vol. 46, No 3

267-280

EN

Carboniferous sandstones and shales encountered in deep boreholes drilled in central Poland, NW of the Holy Cross Mts., represent a pseudoflysch i.e. they show facies features of flysch and, simultaneously, are of cratonic provenance. Clastic sediments were derived from a peripheral bulge formed within the East European Craton as a result of stresses exerted by the accretion/thrust wedge advancing up the marginal part of the craton. In central Poland, NW of the Holy Cross Mts., a Variscan foredeep existed. The foredeep was the depositional site of interfingering exo- and pseudoflysch which, from a geodynamic point of view, are equivalent to an outer molasse. Huge masses of Carboniferous deposits (generally corresponding to flysch) from southwestern and central Poland successively represent, moving from SW to NE, Variscan ortho-, exo- and pseudoflysch.