Regional Seismic Profiles Research Articles

Geophysical study of Hammam Sidi Maamar geothermal site in Central Tunisia for sustainable development

Geophysical methods provide important help to investigate geothermal reservoirs. They permit to delineate deep and near surface structuring and to appreciate fluid circulation. In this study, we performed an integrated geophysical study using regional seismic reflection profiles and local Electrical Resistivity Tomography (ERT) data analyses to identify the relation between faults and specific geothermal pathways around Hammam Sidi Maamar thermal spring site in Hajeb Layoun area (Central Tunisia). The proposed geological model performed from seismic reflection composite sections reveals the geometry in depth series of the Lower Cretaceous from the recharge zone (Jebel Mrhila mountain) to the emergence area of Hammam Sidi Maamar (Jebel Baten Damous mountain) and traces the path of the thermal water, from its recharge area till surfacing, in order to propose a new suitable intake location with higher flow and temperature. The results of seismic and ERT data analysis confirm that the Hammam Sidi Maamar geothermal site is tectonically related to the junction of the NE-SW Baten Damous fault corridor and the NW-SE to E-W northern fault corridor of Hajeb Layoun graben. The water is charged from Lower Cretaceous (Hauterivian to Aptian) outcrop series in Jebel Mrhila Mountain to the West. It flows into the carbonate reservoir below the Hajeb Layoun-Jelma Plain, where the Lower Cretaceous reservoirs are reaching more than 2500 m deep. The reservoir geologic layers show ascent geometry towards Jebel Zaouia Mountain then they sink into the Hajeb Layoun Graben to the East. The thermal water rises to surface thanks to the deep faults that affect the Lower Cretaceous reservoir and the geologic series above. High resolution Electrical Resistivity Tomography panels, we carried out in Hammam Sidi Maamar geothermal site, allowed to locally identify the faulting architecture which controls the flow of hot water. Firstly, filtering and processing of ERT data were performed. 2D ERT modeling, mapping and 3D ERT view interpretation, were also performed to more understand the local tectonic/geothermal flow setting. Finally, to identify the prominent site for lateral and vertical geothermal flow plumes, we propose to drill 50 m–60 m intake well associated with a tectonic junction of the NE-SW Baten Damous fault corridor and the NW-SE to E-W Hajeb Layoun graben fault.

Impact of sea-level fluctuations on the sedimentation patterns of the SE African margin: implications for slope instability

Abstract The sheared-passive margin offshore Durban (South Africa) is characterized by a narrow continental shelf and steep slope hosting numerous submarine canyons. Supply of sediment to the margin is predominantly terrigenous, dominated by discharge from several short but fast-flowing rivers. International Ocean Discovery Program Expedition 361 provides a unique opportunity to investigate the role of sea-level fluctuations on the sedimentation patterns and slope instability along the South African margin. We analysed >300 sediment samples and downcore variations in P -wave, magnetic susceptibility, bioturbation intensity and bulk density from site U1474, as well as regional seismic reflection profiles to: (1) document an increase in sand input since the Mid-Pliocene; (2) associate this change to a drop in sea-level and extension of subaerial drainage systems towards the shelf-edge; (3) demonstrate that slope instability has played a key role in the evolution of the South Africa margin facing the Natal Valley. Furthermore, we highlight how the widespread occurrence of failure events reflects the tectonic control on the morphology of the shelf and slope, as well as bottom-current scour and instability of fan complexes. This information is important to improve hazard assessment in a populated coastal region with growing offshore hydrocarbon activities.

GAS POTENTIAL OF THE DNIPRO GRABEN AND DONETSK FOLDED STRUCTURE JOINT AREA

The location of Karlivka depression is described in this article. The depression is considered as a special geodynamic joint area of the Dnipro graben and Donetsk folded structure. The Phanerozoic geodynamic scale is used together with structural-facial complexes (SFC) developed by V.K. Gavrysh for the Dnieper-Donets Rift. The geodynamic joint area has a crescent shape and is the center of anomalous Early Permian deposits first described by I.I. Demianenko. The Permian Earth’s crust development is the beginning of the Alpine stage of the Earth’s expansion, which rocks (the Early Permian) are characterized by remarkable storage capacity, as well as the further Late Triassic and Early Cretaceous beddings. The integrated processing of remote sensing data and seismic measurements allowed to divide into districts the regional seismic profile named Lozova-Shebelynka-Staropokrivka in accordance with gas potential.

A Late Neogene framework and transpressional system within the Yingxiongling Range, western Qaidam Basin, Northeast Tibetan Plateau: Insights from seismic reflection profiles and active tectonics

The Yingxiongling Range is a topographically unique and active tectonic belt in the western Qaidam Basin that has recorded the structural evolution and interactions between itself and surrounding ranges throughout the Late Cenozoic. Although a large scale fault-fold system within this region accommodates transpressive deformation, the overall kinematic pattern remains highly debated. Regional seismic reflection profiles, earthquake distributions, focal mechanisms, and displacement vector results are used in this study to rebuild a northern verging thrust and wedge tectonic system in a perpendicular direction. Interpretations of newly acquired three-dimensional seismic data, the timing of growth strata, and the kinematics of active structures strongly support lateral structural deformation propagation and evolution of the southern Yingxiongling Range in the Late Neogene. A novel analysis of active tectonic and seismic profiles enables us to rebuild the framework, kinematics, and evolutionary pattern of the Yingxiongling Range. We also provide a new interpretation of lateral differentia along the Yingxiongling Range based on critical taper theory and suggest that this overall structure is an integrated part of the Qimen Tagh Wedge. Since the Late Neogene, rapid uplift in this area occurred in response to northward propagation of the Qimen Tagh Wedge.

Features of conducting of geological exploration on shale gas in Volyno-Podillia at the regional stage of studying

Features of structural conditions of occurrence, gas accumulation, lithofacies, petrophysical and geochemical parameters, shielding factor, character-bearing shale gas saturation are fundamentally different from traditional gas deposits. Stratigraphic shale formation considered as a potential gas deposit. Considering this specificity its allocation and mapping must be executed at an early stage. To delineate gas bearing shale formations of Volyno-Podillia and allocation the most perspective areas offered a complexation of regional seismic survey 2D for great depths (two longitudal profiles of north-western stretch as it continued from the Lublin basin in Poland and 5 crosssections from southwest to the northeast with its total length of about 1500 linear kilometers) with electric prospecting methods of different modifications, caused polarization, electromagnetic methods of regional seismic exploration grids profiles, large-scale atmogeochemical shooting and other direct methods. As the completion of regional stage must be drilling of vertical parametric pilot wells with solid coring from perspective shale strata, laboratory studies of organic matter, of katagenesis, lithofacies and mineralogical composition of shales, their petrophysical and geochemical properties, modeling and testing perspective shale strata using multistage hydrogaps. Prospects of further exploration and it’s complex based on the results geologic-economic evaluation of perspective of petrogas of the region and obtaining results of works start-up phase.

Imaging the East European Craton margin in northern Poland using extended correlation processing of regional seismic reflection profiles

Abstract. In NE Poland, Eastern European Craton (EEC) crust of Fennoscandian affinity is concealed under a Phanerozoic platform cover and penetrated by sparse, deep research wells. Most of the inferences regarding its structure rely on geophysical data. Until recently, this area was covered only by the wide-angle reflection and refraction (WARR) profiles, which show a relatively simple crustal structure with a typical three-layer cratonic crust. ION Geophysical PolandSPAN™ regional seismic programme data, acquired over the marginal part of the EEC in Poland, offered a unique opportunity to derive a detailed image of the deeper crust. Here, we apply extended correlation processing to a subset (∼950 km) of the PolandSPAN™ dataset located in NE Poland, which enabled us to extend the nominal record length of the acquired data from 12 to 22 s (∼60 km of depth). Our new processing revealed reflectivity patterns, which we primarily associate with the Paleoproterozoic crust formed during the Svekofennian (Svekobaltic) orogeny, that are similar to those observed along the BABEL and FIRE profiles in the Baltic Sea and Finland, respectively. We propose a mid- to lower-crustal, orogeny-normal lateral flow model to explain the occurrence of two sets of structures that can be collectively interpreted as kilometre-scale S–C′ shear zones. The structures define a penetrative deformation fabric invoking ductile extension of hot orogenic crust in a convergent setting. Localized reactivation of these structures provided conduits for subsequent emplacement of gabbroic magma that produced a Mesoproterozoic anorthosite–mangerite–charnockite–granite (AMCG) suite in NE Poland. Delamination of thickened orogenic lithosphere may have accounted for magmatic underplating and fractionation into the AMCG plutons. We also found sub-Moho dipping mantle reflectivity, which we tentatively explain as a signature of the crustal accretion during the Svekofennian orogeny. Later tectonic phases (e.g. Ediacaran rifting, Caledonian orogeny) did not leave a clear signature in the deeper crust; however, some of the subhorizontal reflectors below the basement, observed in the vicinity of the AMCG Mazury complex, can be alternatively linked with lower Carboniferous magmatism.

Imaging East European Craton margin in Northern Poland using extended‐correlation processing applied to regional seismic profiles

Imaging East European Craton margin in Northern Poland using extended‐correlation processing applied to regional seismic profiles

Rift structures and its related unconformities on and adjacent the Dongsha Rise: insights into the nature of the high-velocity layer in the northern South China Sea

It is curious that the typical feature of high-velocity layer (HVL) underneath the crust for the magma-rich margin was found in the magma-poor margin of the South China Sea. In order to better understand the nature and age of the HVL in the South China Sea, here we provide seismic imaging on the Cenozoic structure and sedimentation using a regional seismic reflection profile combined with existing drilling data and seismic refraction lines in the northeastern South China Sea. An important finding is that the extent of erosion since Neogene is only on the Dongsha Rise and is much smaller than that of the HVL observed across the northern margin of the South China Sea, which suggests the occurrence of the HVL has no influence on the erosion on Dongsha Rise through Neogene. On the regional seismic profiles, the different structures between the deepwater rifted margins and the continental shelf were also observed. The faults in the Zhuyi Sub-basins on the continental shelf are imaged to be high-angle and bound a series of grabens and horsts. In contrast, the deepwater region is characterized by tilted fault blocks and an array of listric normal faults, which extremely thinned the crust to be ~ 5–10 km. After middle Miocene, active magmatism occurred in the deepwater region at the time of post-spreading of oceanic crust. These listric faults on the hyper-extended crust is interpreted to be conduits for magma migration to the shallower levels. This typical structure in the deepwater region changed the geophysical nature of the HVL underneath the extreme thinned crust, which should be formed before the event of hyper-extension and is likely to be associated with the subduction of the paleo-Pacific toward the Asia in the late Cretaceous. Our study will answer the question why the South China Sea with the HVL underneath the crust is a magma-poor passive margin.

Cenozoic tectonic events and their implications for constraining the structure and stratigraphic styles from rifting to collision at the southeastern margin of the South China Sea

The southeastern margin of the South China Sea (SCS) connects the Southwest sub-basin of the SCS to the north and the collision zone of Nansha–Liyue blocks and Palawan Island to the south, and it records a complex process of the superimposed regional tectonics. Based on recently collected 2D seismic profiles, constraint by wells and outcrop data, our study establishes a stratigraphic framework across different structural units related to various tectonic settings. We identified six major unconformities from the Cenozoic sediment succession and analyzed their geological significance through a comprehensive interpretation of the regional seismic profiles and related well data. Results show the unconformity T7 represents the cessation of the initial rifting along the whole continental margin, which corresponds to the N-S spreading in the central part of the SCS oceanic basin. Reflector T4 is the breakup unconformity that represents the structural evolution transitioning from rifting to post-rifting in the study area. It also synchronizes with the initial deposition of the Nido carbonate platform. Reflector T3 is the most significant regional structural unconformity that corresponds to the cessation of seafloor spreading in the Southwest sub-basin and collision between the Nansha–Liyue blocks and the Cagayan Arc, choking the proto-SCS subduction zone. These tectonic events, also referred to as Sabah Orogeny, indicate the inception of peripheral foreland basin developed from northwest Palawan to the Reed Bank. Major tectonic events recorded in the study area include southward subduction and closure of the proto-SCS as well as opening and cessation of ridge spreading of the SCS, all of which lead to the Nansha–Liyue–North Palawan blocks successively rifting from the South China continent, subsequently drifting southward and ultimately colliding with the Cagayan volcanic arc. Therefore, we propose that the southeastern margin of the SCS has undergone a multi-stage tectonic evolution from the rifting basin through the post-rifting depression to the collisional foreland basin in the Cenozoic.

Compiled potential field data and seismic surveys across the Eastern Brazilian continental margin integrated with new magnetometric profiles and stratigraphic configuration for Trindade Island, South Atlantic, Brazil

ABSTRACTThis work discusses the regional geological and geophysical datasets (potential field data coupled with seismic lines) available across the Eastern Brazilian Continental Margin and addresses tectonic models that have been applied to the geological interpretation of the Vitória-Trindade Chain (VTC). New magnetic data acquired in the Trindade Island is combined with compiled petrological data and geological maps to propose a stratigraphic column with radiometric control for the volcanic sequences. The gravity and magnetic anomaly maps were integrated with regional seismic profiles extending from the continental platform towards the oceanic crust, showing the geomorphology of the Abrolhos Volcanic Complex (AVC) and the VTC. A detailed geological mapping of the Trindade Island was complemented by magnetometric profiles acquired on the island. The magmatic episodes identified in the Trindade Island within different volcano-stratigraphic sequences are, geochronologically, dated by 40Ar/39Ar method as Late Neogene to Quaternary (Pliocene/Upper Pleistocene) and indicate intrusive and extrusive igneous rocks formed on the Mesozoic (Cretaceous) oceanic crust. Models for the emplacement of these volcanic rocks on much older oceanic crust include hotspots and leaking fracture zones. The presence of flat tops as observed in the volcanic banks and seamounts along the Vitória-Trindade volcanic chain indicate abrasion of much higher volcanic edifices that now form the isolated islands in the Trindade-Martin Vaz Archipelago. Geological mapping and detailed magnetometric surveys suggest different rock properties for distinct volcanic episodes that formed the Trindade Island. The remarkable pattern of magnetic anomalies trending NE-SW in the deep-water region of the Espírito Santo Basin, eastwards of the AVC, suggests that the linear chain of volcanic edifices in the VTC may be associated with mantle anomalies caused by a hotspot or plume that was influenced by the E-W direction of leaking transform fracture zones.Abbreviation: Abrolhos Volcanic Complex (AVC); Vitória-Trindade Chain (VTC)

Оценка объемов углеводородных газов газогидратов азербайджанского сектора Южного Каспия по сейсмическим данным

Актуальность исследования заключается в изучении верхней части разреза глубоководной части Южного Каспия с целью выделения зон газогидратов по сейсмическим данным, оценки их мощности, а также подсчета объемов газа газогидратов. Исследование газогидратов Южного Каспия необходимо для достоверной оценки энергетического потенциала углеводородных газов Азербайджана. Результаты изучения газогидратов также могут быть применены для оценки роли газовых гидратов в приповерхностных слоях геосферы, особенно в связи с их возможным влиянием на экологию Каспийского моря, региона и глобальные климатические изменения. Цель исследования заключается в выделении и оценке объемов углеводородных газов газогидратов глубоководной части Южного Каспия по сейсмическим данным. Объектом исследования послужили 17 региональных сейсмических профилей и данные термодинамики региона. По двум площадям Южного Каспия использованы данные скоростного анализа. При интерпретации сейсмических профилей особое внимание уделено идентификации горизонтов, содержащих газогидраты. Методы исследования основаны на наличии прямой связи между особенностями геологического строения зон газогидратов и распределением в среде физических параметров. Индикаторами газогидрата на временном разрезе могут служить аномальные изменения сейсмических характеристик волн: амплитуда, частота, фаза, скорости продольных и поперечных волн. Наиболее широко применяемым сейсморазведочным признаком газогидрата является наличие на сейсмических записях отражающего сейсмического горизонта BSR, а также ярких пятен. По этим критериям интерпретированы все временные разрезы и установлены верхняя и нижняя границы зон с отражениями, характерными для зон газогидратов. Интерпретация данных производилась с помощью лицензионного программного комплекса Kingdom Suite 2017. В результате исследования построены карты нижней и верхней границ зон газогидратов, а также рассчитаны мощности отложений, содержащих газогидраты. Объемы пород, установленные по сейсмическим данным, позволили рассчитать объемы углеводородных газов, содержащихся в газогидратах. Максимальный объем газа в исследуемой зоне составляет 8,06 трил м3 газа. Так же рассчитан объем газогидратов, содержащихся в породе в пределах структур. Ранжирование данных по объемам показало, что в южной части Каспия содержится максимальное количество газа. Исходя из вышеизложенного в глубоководной части Южного Каспия можно выделить две перспективно-газогидратные зоны: высокоперспективная зона в южной части; перспективная зона в северной глубоководной части. Перечисленные зоны накопления газогидратов обеспечат энергетическую безопасность Азербайджана на многие годы.

FEATURES OF THE GEOLOGICAL STRUCTURE OF SEDIMENTARY COVER OF FROLOVSKAYA MEGADEPRESSION DERIVED FROM THE RESULTSOF GENERALIZATION OF GEOLOGICAL AND GEOPHYSICAL DATA

The article is devoted to the features of the geological structure of Jurassic-Cretaceous deposits of Frolovskaya megadepression. These features are derived from the results of the generalization of the materials of regional seismic profiles, maps of gravity and magnetic prospecting, drilling data. The main petroleum prospects are associated with Jurassic deposits and pre-Jurassic basement. We conclude that it is necessary to intensify further researches with carrying out the entire complex of geophysical methods, including magnetic and gravity prospecting with an increased density of observations.

Quantitative analysis of siliciclastic clinoforms: An example from the North Slope, Alaska

Abstract Seismically-imaged clinoforms, constrained by well data, provide a unique opportunity to evaluate sedimentary processes using geometric considerations. The Lower Cretaceous of the Alaskan North Slope is a well-known example of large-scale (600 - 2500 m depositional relief), constructional, siliciclastic clinoforms. This study has depth-converted and decompacted a regional seismic profile in this area to evaluate the relationships among depositional slope angles, shelf-edge trajectories, seismic facies, sediment volume ratios, graded/erosional profiles, and lithologies. Insights from this analysis refute several assumptions about clinoform formation, and could help establish a quantitative methodology for clinoform analysis. Few published examples have been decompacted to estimate original depositional relief. In this study, seismically-imaged slopes of about 1.5° - 3.5° have approximately doubled in magnitude after backstripping, owing to their fine-grained nature and deep burial history. These slopes exceed the largest published estimates of constructional (“graded”) margins. North Slope clinoforms that show more evidence of slope erosion and bypass (out-of-grade) have, on average, lower slope angles than graded clinoforms. This observation is contrary to the assumption that higher slope angles correlate with more extensive erosion. In this study, we hypothesized that erosional modification has lowered the clinoform slope. On average, erosionally-modified clinothems have lower angle shelf-edge margin trajectories and thinner topsets relative to foresets/bottomsets. Additionally, erosionally-modified clinoforms are characterized by higher amplitude seismic facies. Well calibration indicates that the higher amplitude response results from interbedded sandstones and shales; low amplitude seismic facies, associated with graded margins, are more mud-prone. Out-of-grade clinoforms likely facilitate additional bypass/deposition of sediment downslope via sediment gravity flows. Flatter shelf margin trajectories indicate sediment supply exceeds accommodation; this may drive greater slope erosion and bypass. A predictive model, employing these clinoform geometric criteria, can assist in delineating intervals of enhanced bypass/submarine fan development. However, wide applicability beyond this example would require additional calibration and further testing.

Seismic stratigraphy of the Mianwali and Bannu depressions, north-western Indus foreland basin

Regional seismic reflection profiles, deep exploratory wells, and outcrop data have been used to study the structure and stratigraphic architecture of the Mianwali and Bannu depressions, north-western Indus foreland basin. Synthetic seismograms have been used to identify and tie the seismic horizons to the well data. Nine mappable seismic sequences are identified within the passive and active margin sediments. In general, the Mianwali and Bannu depressions deepens towards north due to the flexure generated by the loading and southward shifting of the thrust sheets of the North-western Himalayan Fold and Thrust Belt. The seismic profiles show a classic wedge shaped foreland basin with a prominent angular unconformity which clearly differentiates the active and passive margin sediments. The onlap patterns in the Late Cretaceous sediments suggest the initial onset of foreland basin formation when the Indian Plate collided with Eurasian Plate. As the collision progressed, the lithospheric flexure caused an uplift along the flexural bulge which resulted in onlaps within the Paleocene and Eocene sequences. The tectonic activity reached to its maximum during Oligocene with the formation of a prominent unconformity, which caused extensive erosion that increases towards the flexural bulge.

Rapid post-rift tectonic subsidence events in the Pearl River Mouth Basin, northern South China Sea margin

Data from 26 drill wells and 27 regional seismic profiles were integrated to investigate the timing, phase and origin of the post-rift subsidence in the middle to eastern Pearl River Mouth Basin (PRMB) of the northern South China Sea using the traditional 1-D backstripping technique. Different from previous research of backstripped tectonic subsidence in the basin, we calculated the tectonic subsidence using the newly built local porosity-depth relationships for decompaction and updated sedimentological and paleontological data for paleobathymetry reconstruction. Well-data based subsidence curves reveal a roughly decaying pattern in both the magnitude and rate of the post-rift subsidence in the PRMB, which is in accordance with the general decreasing trend of the thermal subsidence typical of a passive margin. Two events of rapid post-rift tectonic subsidence were identified, which occurred in the Early to early Middle Miocene and the Pliocene. The timing of the first rapid post-rift subsidence event varies and is earlier in the southern rather than northern part of the basin. Additionally, the amplitude of contemporaneous tectonic subsidence is greater in the southern part of the basin. The second rapid tectonic subsidence event occurred simultaneously in both the southern and northern parts of the basin, with the amplitude of subsidence being much greater in the southern part. We associate the first rapid subsidence event with the southward jump of the South China Sea spreading ridge, which occurred between the Oligocene and Early Miocene, while the second event with the arc-continent collision at Taiwan since the latest Late Miocene. The southern PRMB in the deep-water slope area shows a much higher magnitude of tectonic subsidence in both events than its northern counterpart in the shelf area, which could be associated with its much thinner lithosphere. The latter could cause upswelling of denser lower crust and upper mantle material, resulting in more rapid tectonic subsidence in the southern PRMB.

Geological and geodynamic reconstruction of the East Barents megabasin from analysis of the 4-AR regional seismic profile

The article considers problems related to the geological structure and geodynamic history of sedimentary basins of the Barents Sea. We analyze new seismic survey data obtained in 2005–2016 to refine the geological structure model for the study area and to render it in more detail. Based on the data of geological surveys in adjacent land (Novaya Zemlya, Franz Josef Land, and Kolguev Island), drilling, and seismic survey, we identified the following geodynamic stages of formation of the East Barents megabasin: Late Devonian rifting, the onset of postrift sinking and formation of the deep basin in Carboniferous–Permian, unique (in terms of extent) and very rapid sedimentation in the Early Triassic, continued thermal sinking with episodes of inversion vertical movements in the Middle Triassic–Early Cretaceous, folded pressure deformations that formed gently sloping anticlines in the Late Cretaceous–Cenozoic, and glacial erosion in the Quaternary. We performed paleoreconstructions for key episodes in evolution of the East Barents megabasin based on the 4-AR regional profile. From the geometric modeling results, we estimated the value of total crustal extension caused by Late Devonian rifting for the existing crustal model.

Tectonic and stratigraphic evolution of the Punta del Este and Pelotas basins (offshore Uruguay)

Regional seismic reflection profiles and well data from the Uruguayan margin were integrated in order to analyse and illustrate its tectonic and stratigraphic evolution. The evolution of the Punta del Este and Pelotas basins is divided into four major phases: pre-rift (Palaeozoic); rift (Jurassic–Early Cretaceous); transition (Barremian–Aptian) and post-rift (Aptian–Present). Each of these phases is characterized by a specific structural configuration and a stratigraphic architecture related to basin type, tectonic elements, sediment supply and base-level changes. During the geological evolution of the Uruguayan continental margin, a NE migration of depocentres occurred. The Cretaceous depocentre is located in the Punta del Este Basin, while the Cenozoic depocentre is located in the Pelotas Basin.

Petroleum systems modelling as an exploration tool: from surface seismic acquisition to basin modelling: a case study from a periplatform basin in Northern Adriatic

The Adriatic Sea hosts important historically explored hydrocarbon provinces. In the northern areas, the main sources of hydrocarbon productivity are from biogenic gas reservoirs located in Quaternary thick deltaic depositional systems related to the Apennine and Dinaric foreland domain. In addition, Mesozoic thermogenic oil plays were identified and exploited in the Southern areas. Herein, we use basin and petroleum systems modelling (BPSM) techniques to investigate the still unproved thermogenic hydrocarbon potential of deep Mesozoic basins in the North Adriatic Sea and to correlate the results with the sedimentary evolution of proven petroleum systems in the Central and South Adriatic, both in the Italian and Croatian offshore areas. We used the regional CROP-M16 marine seismic profile in the eastern segment of the study area, where it cuts the western margin of the Dinaric carbonate platform and reaches the pelagic domain of the Umbria-Marche basin intersecting the Barbara isolated platform (Figure 1). We reprocessed the 2D seismic data set to obtain the correct dips and depths of the geological structures from a depth-migrated profile. During the interpretation phase, we integrated the information from profile CROP-M16 with the orthogonal CROP-M17B and C profiles that are intersecting the Alessandra-001 exploration well. The interpretation allowed a detailed analysis of the main lithological discontinuities and of the fault system. We used the interpreted features together with the petrophysical parameters inferred by the available wells in the area and by literature, for 2D petroleum systems modelling. Our simulation integrated the available information to produce a set of possible scenarios of basin development, with the objective to understand the maturation and migration of hydrocarbons.

Paleogene and Neogene kinematics of the Alpine-Carpathian fold-thrust belt at the Alpine-Carpathian transition

In this study we analyze a ~300km long segment of the Alpine-Carpathian orogen using novel outcrop data and regional seismic profiles from the West Carpathians to unravel the kinematics and timing of Eocene to Late Miocene deformation of the fold-thrust belt. Comparison with data from the Eastern Alps and the Vienna Basin leads to an updated tectonic model for the Paleogene and Neogene of the Alpine-Carpathian transition, which includes three stages:(1) Eocene to Early Oligocene NNW-directed foreland-propagating thrusting. Thrusts are directed perpendicular to the strike of the European foreland in the Outer West Carpathians (OWC) and sub-parallel to thrusts observed in the Eastern Alps west of the Vienna Basin.(2) Continued Late Oligocene to Early Miocene NNW-directed foreland-propagating thrusting simultaneous with sinistral strike-slip reactivation of former nappe boundaries in the hinterland of the active thrusts. This deformation corresponds to the early stage of eastward lateral extrusion of the Eastern Alps. The ENE-striking sinistral faults in the OWC are kinematic equivalents of the SEMP fault system in the Eastern Alps, which was active at the same time. The latest stage of thrusting is characterized by SSE-directed out-of-sequence thrusts in the hinterland of the OWC and the reactivation of Variscan basement thrusts in the European foreland as SSE-directed backthrusts.(3) Formation of (N)NE-striking sinistral strike-slip faults which are kinematically linked to (N)NE-directed out-of-sequence thrusts post-dating NNW-directed thrusting. The sinistral faults formed coeval with the opening of the Vienna pull-apart basin during the Middle to Late Miocene stage of lateral extrusion.Unlike proposed in previous studies the West Carpathians do not appear to be affected by Oligocene to Early Miocene crustal-scale wrenching of the Pieniny Klippen Belt. Our data show that the deformation of the PKB is in line with the Eocene to Late Miocene tectonic evolution reconstructed for the OWC.

Tectonics and petroleum potential of the Kazan–Kazhim aulacogen, East European Platform

The paper presents a new interpretation of the surface structure of the crystal basement of the Kazan–Kazhim aulacogen based on geological–geophysical data and reprocessed regional seismic profiles. It is shown that the formation of the Vyatka uplift is related to deep reverse thrusts and that tangential stresses were a major factor in the formation of the aulacogen. The presence of a large left-lateral strike-slip fault is established, which cuts the Kazan–Kazhim aulacogen from west to east. Our data confirm wide-spread horizontal movements occurred in the crust in the eastern part of the East European Platform and help to optimize hydrocarbon exploration in the region.