Stratigraphic Scheme Research Articles

Integrated well log and 2-D seismic data interpretation to image the subsurface stratigraphy and structure in north-eastern Bornu (Chad) basin

Structural and stratigraphic mapping within the Bornu Basin in north east Nigeria was commonly carried out using traditional field geological methods. However, such traditional approaches remain inadequate in the semi-arid region characterised by topographically flat areas and lack of continuous bedrock outcrops that are mostly concealed beneath sand cover. Previous studies in the north-eastern part of the basin carried out using ditch cuttings from few wells and disconnected seismic data were largely inadequate and the resulting stratigraphic analyses were more often generalised. This paper presents an integrated structural and stratigraphic study of the basin using combined subsurface geophysical datasets. A Combined Log Pattern (CLP) method is a well log analysis, which utilises various well log data including gamma ray, resistivity, bulk density and sonic logs to identify lithology and stratigraphic boundaries of subsurface formations. This method is applied to constrain the subsurface stratigraphy of the north-eastern part of the Bornu Basin bordering the Lake Chad. In addition to qualitative combined well log analysis, the time-depth relationship of the sonic log and seismic data was quantitatively determined by tying a well with an intersecting seismic section to validate the stratigraphic facies horizons identified. Four well log facies and their environments of deposition were characterised from the combined well log analysis of the different log types. It is discovered that the Cretaceous basement structural features controlled the deposition of overlying formations in the basin. Without intact core data, the shallower wells were discovered to have bottomed over subsurface horst features while deeper wells penetrated into the basal facies contained mainly within the grabens. Main subsurface structural lineaments in the area include NW-SE, NE-SW and NNW-SSE trending faults, which mainly formed the horst and graben features. Some stratigraphic formations described in previous generalised stratigraphic schemes for the Bornu Basin were herein not found in the north-eastern part of the basin.

The Alan-Kyr Coniacian–Campanian section (Crimean Mountains): Biostratigraphy and paleobiogeography aspects

This investigation continues the study of the Alan-Kyr reference section (Central Crimea, Belogorsk Region). The zoned age difference in the stratigraphic scheme of the Upper Cretaceous in the Eastern European Platform is considered according to benthic and planktonic foraminifers, as well as radiolarians in the Alan-Kyr section. This fact can be explained based on the suggestion that stratigraphically important taxa could have appeared in Crimea several million years earlier than on the platform, where they could migrate under the great global eustatic transgression in the Early Campanian. We also considered the influence of paleobiogeographic conditions on the taxonomic composition of the zoned foraminifer complexes, both benthic and planktonic.

Reorganisation of the Triassic stratigraphic nomenclature of northern Switzerland: overview and the new Dinkelberg, Kaiseraugst and Zeglingen formations

In the context of the harmonisation of the Swiss stratigraphic scheme (HARMOS project), the stratigraphic nomenclature of the Triassic sedimentary succession of northern Switzerland has been reorganised to six formations (from base to top): Dinkelberg, Kaiseraugst, Zeglingen, Schinznach, Bankerjoch, and Klettgau Formation. The first three are formally introduced in this paper. The Dinkelberg Formation (formerly «Buntsandstein») encompasses the siliciclastic, mainly fluvial to coastal marine sediments of Olenekian to early Anisian age. The formation is some 100 m thick in the Basel area and wedges out towards southeast. The Kaiseraugst Formation (formerly «Wellengebirge») comprises fossiliferous siliciclastic and carbonate sediments documenting a marine transgressive—regressive episode in early Anisian time. It starts with sandstone, dolomite, continues with subtidal limestone and marl and ends with bituminous shale and supratidal dolomite. Thickness decreases from approximately 50 m in the High Rhine area to 10 m in the south and east. In the Lake Constance area, a transition to the siliciclastic marginal facies of the Vindelician High (Eschenbach Formation in Germany) is documented by borehole evidence. The Zeglingen Formation (formerly «Anhydritgruppe») documents a regressive marine evaporitic megacycle during the Illyrian (late Anisian). At most places, except in far eastern Switzerland, it starts with massive halite deposits. It continues with sulfate and marl sequences and ends with littoral stromatolitic dolomite. In the WSW–ENE trending depot centre total formation thickness is 150 m and more, and thickness of salt layers reaches up to 100 m. In the High Rhine area, the thickness is reduced due to subrecent subrosion. At some places evidence points to syn- to early-post-diagenetic erosion. For practical reasons, the six formations are organised in three lithostratigraphic groups: Buntsandstein Group (with the Dinkelberg Formation), Muschelkalk Group (combining the Kaiseraugst, Zeglingen and Schinznach Formations) and Keuper Group (combining the Bankerjoch and Klettgau Formations).

A Multidisciplinary Tool for the Development of a Regional-scale Geotechnical Model: A Case Study in the North-Western Adriatic Coastal Area

The paper describes the geotechnical model of a coastal flat area facing the Adriatic Sea, between the municipalities of Cesenatico and Bellaria-Igea Marina (Emilia-Romagna region, Italy). On the basis of a large experimental database provided by the Geological, Seismic and Soil Survey of the Emilia-Romagna Authority, a stratigraphic scheme of the upper 40 m of this coastal plain subsoil has been defined and reliable estimates of parameters for the different soil units have been derived. The accurate mechanical characterization of soils, also reflecting their sedimentological framework, allows the development of a regional-scale geotechnical model providing a reliable and useful support to geotechnical engineers working in this area or similar geological environments.

Upper Neopleistocene ostracods from the southeastern West Siberian Plain and their stratigraphic significance

In the upper Neopleistocene of the southeastern West Siberian Plain, two ancillary biostratigraphic units by ostracods in the rank of faunal beds, namely, the Cypridopsis vidua–Herpetocypris reptans Beds (Ermakovo Horizon and the lower part of the Karginsky Horizon) and the Ilyocypris pustulata Beds (Karginsky Horizon), are recognized for the first time. The age of the Ilyocypris pustulata Beds is substantiated by a series of radiometric datings. The Eucypris pigra–Cyclocypris laevis–C. triangula ostracod assemblage from the upper part of the Sartan Horizon, whose age is also justified by a radiometric date, is characterized. The new data on ostracods supplement the materials available on this group of fauna and refine the Quaternary regional stratigraphic scheme of the West Siberian Plain.

Late Pleistocene stratigraphy according to the sediment sequence from eastern Kola Peninsula, Ponoi River Valley (North-Western Russia)

The sedimentary sequence from the local stratotype section of the Mikulinian (MIS 5) marine deposits at the Ponoi River Valley, easternmost Kola Peninsula, North-Western Russia, has been investigated to define the geological and numerical ages, and chronostratigraphic position of a marine unit identified previously as a lithostratigraphic unit of the lower part of the Mikulinian and named the Ponoi Beds in the regional Kola stratigraphic scheme. The new data indicate that the Ponoi Beds has two-part sedimentary succession, which was formed during two successive interglacial Boreal and Belomorian marine transgressions in the Mikulinian (MIS 5) time. The lower clay part of this succession accumulated in the interglacial marine basin until c. 96 ka under favourable environmental and climatic conditions. The upper sandy part of this lithostratigraphic formation, also previously attributed to the Ponoi Beds, accumulated in the late Mikulinian marine basin about 70 ka ago under relatively cold and damp climate conditions. In accordance with our new data obtained in this study, it has to be attributed to another marine unit referred to as the Strelna Beds, formed during the second Belomorian interglacial marine transgression, also during the Mikulinian time. Formerly the Strelna Beds was correlated with the Podporozhian (MIS 4) Horizon in the current regional Kola stratigraphic scheme. Both the Ponoi and Strelna Beds marine sediments have to be related and linked with the marine basin during MIS 5. These marine units have to be correlated with the Mikulinian (MIS 5) Horizon.

Eocene age of the Baranowski Glacier Group at Red Hill, King George Island, West Antarctica

AbstractRadiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula) on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud-, silt-, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus, dicotyledonous, thermophilous ferns) and numerous coal seams (vitrinitic composition) that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole-rock K-Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1) from about 51–50 Ma; and (2) 46–42 Ma,i.e.during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano-clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.

Discussion on ‘Late Cenozoic geological evolution of the northern North Sea: development of a Miocene unconformity reshaped by large-scale Pleistocene sand intrusion’, Journal of the Geological Society , 170, 133–145

In their recent paper, Loseth et al . (2013) propose a new model for the late Cenozoic evolution of the northern North Sea. They propose that during the early Pleistocene ( sensu ICS 2013), large volumes of sand were ejected from the Paleocene through the Eocene–Oligocene Hordaland Group, and deposited both as extrusive sand on the Pleistocene seafloor and as intrusive sand within the Oligocene section, c . 180 m below the seafloor. The paper builds on two earlier studies: (1) that by Loseth et al . (2012) in which the Pleistocene extrusive sand is presented in more detail; (2) that by Rodrigues et al . (2009) in which an experimental model related to such sand deposition is presented. The model of Loseth et al . (2013) is illustrated by a seismic section in their figure 12, showing intrusive sands within the Oligocene and extrusive sands within the Pleistocene. Details of this model, such as feeder dykes and blowout fissures that create ditches, are shown in their figure 8 (Visund Field) and figure 11 (Snorre Field). The geological events are summarized in their figure 16. As illustrated on a stratigraphic scheme (their figs 2 and 15), Loseth et al . interpret the Oligocene sands as being injected from a Paleocene parent sand. They propose that the mounds at the top of the Hordaland Group resulted from forced folding over the sand injectites, as exemplified in their figure 11. Furthermore, Loseth et al . interpret escarpments on the Top Hordaland Group Unconformity as cliff sections similar to those of southeastern England today and claim that the northern North Sea was subaerially exposed during a 10 myr Miocene time span. Loseth et al . (2012, 2013) not only challenge our previous turbiditic interpretation of the Pleistocene sand (Eidvin & …

QUESTIONS STUDYING OF THE EOCENE SEDIMENTARY COMPLEX OF THE CRIMEA AND KERCH PENINSULA

«Stratigraphic scheme of Paleogene deposits of the southern regions of Ukraine» (1993) is used for stratification of Paleogene sediments of Ukraine today. Actualized stratigraphic scheme of Eocene deposits of the Crimea and Kerch peninsula is presented in the second article. This scheme has been made based on the results of compilation and analysis of data of litology and paleontology, of using biostratigraphic developments of different micro and macro fossils and of modern views in stratigraphy. Research has been carried out within requirements of Stratigraphical Code of Ukraine (2012). Modern International Stratigraphic Chart (2012-2014) and modernized Regional stratigraphic Scale of Paleogene of Ukraine (2013) were accepted in the proposed scheme. Description and litological-paleontological characteristics of 18 local units of Eocene as part of the Bakhchisaraian, Simferopolian, Novopavlovkian, Kumian and Almian regional stages are given. Stratigraphical volume, spreading and age of described suites, series, members and beds with faunas were clarified. Six new local units have been described in the article for the first time. Among them marls and calcareous clays with Acarinina rotundimarginata and Globigerinatheka subconglobata (Novopavlovkian + Kumian regiostages), the Malobabchinskaya suite (Bakhchisaraian – Almian regiostages) were proposed in the scheme of the Kerch peninsula; the Kyshlav series (Bakhchisaraian regiostage), the Slavutych suite (Simferopolian regiostage) and the Dmytrivka series (Bakhchisaraian – Simferopolian regiostages) were proposed in the scheme of the Crimea’ plain; the Kyshlav series (Bakhchisaraian regiostage) and clayey limestones with small nummulites and Assilina tenuimarginata were propodes in the scheme of Crimea foothills. Duration of hiatuses, reduction of stratigraphic volume of local stratas in peripheral sections of sedimentary basins are shown at these stratigraphic schemes.

PALEOGENE DEPOSITS OF THE NORTHERN UKRAINE PALEOSEDIMENTARY PROVINCE

A conducted review of lithological and paleontological studies of the Paleogene local stratigraphic subdivisions of the Northern Ukraine for the last 20 years has resulted in the revision of the existing local stratigraphic scheme. Proposed new (actualized) stratigraphic scheme of Paleogene deposits Dnieper-Donets basin, Ukrainian shield and margins Donetsk folded structure (by Stratigraphic code of Ukraine, 2012). A detailed description of Sumy Fm., Merla Fm., Kaniv Fm., Buchak Fm., Kyiv Fm., Obukhiv Fm., Mezhyhiriya Fm. Zmiiv Fm., and Syvach Fm. are described for the first time in the present study as independent stratigraphic subdivisions. New stratigraphic units have been identified in the rank of Strata. Sratigraphic statuses of the some local stratigraphic subdivisions have been emended. The problematic nomenclatures questions have been discussed. Directions for further research are outlined.

Stratigraphic and tectonic settings of Early Paleolithic of North-West Armenia

The Quaternary stratigraphy and tectonic development of the southern Javakheti Upland and the adjacent Upper Akhurian and Lori uplifted basins in NW Armenia (Lesser Caucasus) and geological position of the early and middle Acheulian lithic industries were studied using a multi-method approach. Studies of sedimentary sections, petrological and geochemical correlation of lavas and tuffs, K–Ar dating of volcanic rocks and SIMS 238U–206Pb dating of tuffs, examination of obtained fossils and pollen analysis, and determination of remanent magnetic polarity of volcanic rocks and clastic sediments have been used to compile the stratigraphic scheme and to estimate the age of units.The low-mountain topography was differentiated to ridges and basins to the beginning of Quaternary. The eruptions of basalts and basaltic andesites evened topography of the Upper Akhurian and Lori basins in the Gelasian. The lava flows spread along big river valleys at tens of kilometers. At the late Gelasian, the eruptions of basaltic trachyandesites, trachyandesites and dacites replaced the basaltic eruptions. The latter dammed the Akhurian River flowing to the south and the upper Akhurian River found the flowing to the east via the valley-like depression of the Karakhach Pass to the Dzoraghet-Debed valley. The course-grained tuffaceous-clastic Karakhach unit was deposited during the Olduvai subchron (not earlier than 1.9–1.85 Ma) and the earliest Calabrian. The water transit between the Upper Akhurian and Lori basins was interrupted later because of rise of the Karakhach Pass. Volcanic activity renewed for a short time in the early Calabrian (∼1.7 and 1.5–1.4 Ma). The end Calabrian and earliest Middle Pleistocene sedimentation (∼1–0.5 Ma) occurred in stagnant water, partly lacustrine conditions. This was expressed by formation of the relatively fine-grained Kurtan unit. During the last ∼0.5 Ma, the region underwent flexure-fault deformation and tectonic uplift at 350–800 m.The epoch of formation of the Karakhach unit was characterized by middle mountain topography and humid climate. Not later than 1.85 Ma, the region was occupied by the earliest hominines producing lithic industries of the Early Acheulian aspect. They contained crude hand-axes and other macro-tools, made of local dacite and basalt (sites of Karakhach, Muradovo and Agvorik). Early appearance of these industries might be caused by natural parting of dacite and basalt to tabulated fragments that gave a possibility to make such macro-tools. The Middle Acheulian artifacts were found in the Kurtan I section of the Kurtan unit.

Методы разработки зональной стратиграфической схемы верхнего мела Западной Сибири по фораминиферам

Методы разработки зональной стратиграфической схемы верхнего мела Западной Сибири по фораминиферам

The Pleistocene stratigraphy of the south-eastern sector of the Scandinavian glaciation (Belarus and Lithuania) : a review

The paper summarises geological and palaeobotanical investigation data on Pleistocene sediments of recent decades in Lithuania and Belarus. The main problems in Pleistocene stratigraphy and correlation of sections are discussed. As a result the chronostratigraphical correlation chart of Lithuania and Belarus is presented and some changes in local stratigraphic schemes proposed. The majority of the stratigraphical units is comparable and correlates well however some unsolved stratigraphical problems still exist. To solve these problems additional very detail investigations are needed by applying the new modern methods. The lack of the absolute dates of the Pleistocene sediments is the main problem in both countries.

STRATOTYPE SECTIONS OF THE OXFORDIAN OF UKRAINIAN PRECARPATHIANS

The results of complex study of the Oxfordian deposits in Ukrainian Precarpathian are presented. According to today stratigraphic scheme, the Oxfordian deposits in the territory of Carpathian Foredeep are represented by reefogenic complex, in which Boniv, Rudky and Gorodok suites were allocated. Only Boniv suite stratotype was described by author (V.G. Dulub, 1995). In the results of our investigations the sratotypes of Rudky and Gorodok suites are determined and consistently described, and the extended stratotype of Boniv suite is specified. Section opened by the well Pidluby-105 in interval 922,5–1002,8 м is proposed as a stratotype of the Rudky suite. The stratotype of Boniv suite was opened by the well South Kochanivka-1 and by author was determined in interval 2770–2952 м. According by new data the suite is determined in interval 2720–2952 м. For the Gorodok suite is proposed the folding stratotype, which is composed of the sections opened by wells (from below to up): Dashava-405 (2180–2150 м), Rava-Ruska-2 (1189–1165 м), South Grynivka-2 (3330–3298 м), Didushychy-1 (2627–2597 м), Rudky-120 (1600–1570 м), Verchany-1 (1988–1960 м). Lithological and paleontological characteristic of these sections are given.

Trilobites from the Giles Creek Dolostone (Cambrian Series 3, Stage 5; Templetonian) Amadeus Basin, central Australia

AbstractTwelve trilobite species, plus rare agnostid arthropods, are described from the Giles Creek Dolostone (Cambrian Series 3, Stage 5; Templetonian) at Ross River Gorge and Gaylad Dam in the north‐eastern Amadeus Basin, Northern Territory, central Australia. Amphoton krusei sp. nov., Nepea ommacrada sp. nov., Penarosa oepiki sp. nov. and Schopfaspis shergoldi sp. nov. are described in association with Deiradonyx toddi Öpik, 1982, Dinesus sp., Kootenia sp., Pagetia silicunda Jell, 1975, Solenoparia sp., Tonkinella? sp., Xystridura filifera Öpik, 1975a, and Xystridura gayladia Öpik, 1975a, in addition to indeterminate agnostids. Pagetia silicunda and Xystridura filifera suggest an early Templetonian age, within the Pentagnostus anabarensis or Pentagnostus praecurrens Zone. This is supported by the co‐occurrence of Amphoton Lorenz, 1906, Deiradonyx, Öpik, 1982, Dinesus Etheridge, 1896 and Kootenia Walcott, 1889, all of which occur in Templetonian successions in the Georgina Basin (Northern Territory and Queensland), Gnalta Shelf (western New South Wales) and the Heathcote Greenstone Belt (Victoria). We argue that the Tempe Formation (central Amadeus Basin) and the Giles Creek Dolostone are not contemporaneous as previously suggested, indicating that regional stratigraphical schemes need to be amended.

Stratigraphic scheme for the neogene deposits of the Northern Black sea region and adjacent part of the Ukrainian shield

There are currently two stratigraphic schemes (1993 and 1995) utilised for stratigraphic subdivision of the Neogene deposits of the Northern Black Sea region and adjacent parts of the Ukrainian Shield. These schemes are based on biostratigraphic (molluscs, foraminifers, ostracods) and lithological studies and therefore local stratigraphic subdivisions used in these schemes (according to the Stratigraphic Code of Ukraine, 2012) are essentially biostratigraphic subdivisions, namely «beds with fauna». This fact impedes using these stratigraphic schemes as a basis for developing legends for large-scale and medium-scale geological maps. A new modernized stratigraphic scheme of the Neogene deposits of the Northern Black Sea region and adjacent parts of the Ukrainian Shield is introduced in this study. The scheme is supported by new and previously published data on the distribution of lithological types of Neogene sediments and their detailed biostratigraphic analysis. The stratigraphic scheme of the Neogene deposits of the Southern Ukraine (1995) includes regional stratigraphic subdivisions – «horizons» that are subordinate to regional stages. The new scheme suggests using only those horizons that are characterized by mollusc assemblages or other paleontological groups. These assemblages should be typical for different facies of coeval sediments in the most structural-facies zones of the Southern Ukraine. The volume of local stratigraphic subdivisions in previous stratigraphic schemes (1993, 1995) has been revised; their stratigraphic status and names have been emended. New local stratigraphic subdivisions, namely formations, beds and strata, have been identified based on the similarity of lithology and biostratigraphy between Neogene deposits of different investigated areas. The age of those local stratigraphic subdivisions has been determined by key species of different fossil groups. These subdivisions have been correlated with the Neogene regional stages of the Eastern Paratethys. Based on the presence of representative fossil assemblages within some local stratigraphic subdivisions, «beds with fauna» have been introduced. The suggested stratigraphic scheme of the Neogene deposits of the Northern Black Sea region and adjacent parts of the Ukrainian Shield consists of two sheets with a graphic image of the scheme, three graphic appendices and text. Sheets demonstrate the spread areas of local stratigraphic subdivisions, their spatial and stratigraphic correlation and names. Sheet 1 includes a schematic diagram of the Neogene deposits from the west to the east: Western structural-facies zone – Genichesk structural-facies subzone – Priazovye; Sheet 2 – from the south to the north: Genichesk structural-facies subzone – Kakhovka structural-facies subzone – the southern slope of the Ukrainian Shield. The «beds with fauna» have been shown for local subdivisions. The comparison of local stratigraphic subdivisions from this scheme with those from the previous schemes (1993, 1995) is provided in graphic appendices.

Towards updated stratigraphic frameworks for Australia

A standardised and precise timescale is invaluable to geological research and crucial to meaningful correlation at local, regional and global scales for both researchers and industry. Modern techniques and instruments are delivering increasingly accurate ages, and biozonation schemes are continually refined and standardised on a global basis. Updates to the international geologic time scale occur regularly, and constant updates to stratigraphic schemes are required to ensure that major regional geological events can be correlated across the Australian margin. Several different sequence stratigraphic schemes have been developed for the basins of the North West Shelf. These range from basin-specific to margin-wide schemes. While these schemes have much in common, there are some significant differences. Understanding the nature and reasons for both the differences and commonalities is an essential step for improving understanding of the region’s evolution. The continuing improvements being made to biostratigraphic zonation schemes for the Triassic to Cenozoic will assist in better defining sequences and correlations, and allow geologists to better understand whether apparent differences in sequence definition across the margin are real, and therefore if they reflect different basin histories or are simply an artefact of biostratigraphic imprecision. Geoscience Australia endeavours to—in collaboration with industry—produce unified stratigraphic schemes for the various hydrocarbon provinces. This work will fundamentally support present and future acreage releases.

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

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).

LITHOSTRATIGRAPHIC SCHEME AND PALEOGEOGRAPHIC CONDITION OF KRASNOKUTSK TITANIUM-ZIRCONIUM DEPOSIT CREATION

На основі даних Проекту модернізованих стратиграфічних схем України розроблено літостратиграфічну схему Краснокутського родовища титано-цирконієвих руд, а також здійснено палеореконструкцію седиментаційного басейну Субпаратетісу для середньоновопетрівського часового інтервалу міоцену.

До стратиграфії конксько-сарматських відкладів Південної України по молюскам (середній - верхній міоцен)

The results of study marine bivalve and gastropod from konkian-sarmatian deposits of the Southern Ukraine are gave. Their lateral and vertical distribution is studied. Local stratigraphic schemes for the Northern Black Sea region,Flat Crimea and Kerch peninsula.Key words: Bivalvia, Gastropoda, biostratigraphy, Middle-Upper Miocene, Southern Ukraine, Eastern Paratethys.