Foreland Basin Research Papers - Academia.edu (original) (raw)

2025, Geological Quarterly

Multiproxy sedimentological, gamma-spec tro met ric, foraminiferal, cal car e ous nannoplankton, and otolith data were used for the re con struc tion of the Badenian (Mid dle Mio cene) his tory of the Moravian part of the Carpathian Foredeep. The study mate rial orig i nated from the new bore hole LOM-1, which drilled >20 metres of mo not o nous clayey siltstones with ex cep tion ally rich and well-pre served microfossil as sem blages. Dis tal parts of the Carpathian Foredeep (a forebulge depozone) are exposed in this suc ces sion. Gen er ally, a quiet en vi ron ment of outer shelf to up per bathyal of mo not o nous clayey silts was in terpreted, which is typ i cal for the prox i mal parts of a pe riph eral fore land ba sin. The sec tion stud ied can be sub di vided into six in ter vals, con firm ing the cy cli cal char ac ter of Mid dle Mio cene sed i men ta tion in the Cen tral Paratethys. Interannual os cil lations of nu tri ent con tent, tem per a ture and/or sa lin ity are in ter preted based on the os cil la tions of geo chem i cal as well as palaeo bio logi cal data. The turn over con nected with the ini ti a tion of the Mid dle Mio cene Cli ma tic Tran si tion is re corded above the LO (last oc cur rence) of Helicosphaera waltrans in agree ment with pre vi ous ob ser va tions in the Carpathian Foredeep. The changes in clude cool ing, a de crease in nu tri ents, a prob a ble in crease of the sa lin ity of sur face wa ter, and in crease of sea son al ity. Sea son al ity was man i fested by an al ter na tion of mixed and strat i fied wa ter col umns with a sea sonal in put of nutri ents. Con cern ing nu tri ents, sources of sea sonal riverine in put or sea sonal upwelling are both pos si ble.

2025, Tectonics

This paper sheds light on the evolution of the Patom belt. This mountain range draws an arc along the south-eastern edge of the Siberian craton. It is supposed to be of Caledonian age and to result from the accretion of microcontinents against the craton, but up to now, its detailed stratigraphic and tectonic history was unclear. A field study allows us to precise it. The sedimentary record is marked by a slow evolution with stable periods of more than 250 Ma. The observed sedimentary succession confirms the existence of a passive margin setting in the Late Riphean (900 Ma), followed during the Vendian (650-600 Ma) by the obduction of the Baikal-Muya ophiolites belt and a foredeep inversion. After then, a late Cambrian extension occurred, which is first described in this paper. The second collision stage occurred after 385 Ma, in the late Devonian-Early Carboniferous. Sedimentary and tectonic data are interpreted in the light of the geodynamic evolution of Siberia, which is dominated by continental collages against the Siberian craton. Field data reveal a homogeneous direction of compression from the inner areas to the foreland. Whereas the inner range displays metamorphosed units deformed in the ductile domain, deformation is weaker in the foreland, which developed above the cratonic crust. We relate this high deformation gradient to the presence of the stiff craton which impeded strain propagation. The irregular shape of the craton as well as pre-existent basement topography can explain the different tectonic styles observed along the belt.

2025, International Journal of Geosciences

The following paper presents an integrated geological (field observations, wells data) and geophysical data (Gravity measurements and seismic profiles) in Tellian foreland domain of the northeastern Tunisia (Mateur plain) served for a new proposed structural map with many faults already recognized or supposed by traditional structural studies and highlights major regional accidents.

2025, Iraqi Journal of Science

The study area is situated in the northern part of the Arabian Plate. The evolution of the Zagros Foreland basin is related to the compressional tectonic system at the beginning of the Tertiary Period. This study gives an adequate nomenclature for the Oligocene – Early Miocene Sequence is Missan Group. The Buzurgan Oilfield was chosen to represent the stratigraphic column corresponding to that period. These sediments were subdivided into two cycles, where each one ends by a sequence boundary, equivalent to the lowstand siliciclastic residues in the basin center. The first cycle, Paleocene-Oligocene Epoch, was deposited marly limestone with planktonic foraminifera in the basin center during the transgressive and highstand conditions. The Lower Missan Group was deposited during the latest Oligocene lowstand conditions and overlaid the deep marine Oligocene sediments. The second cycle represented the Early Miocene Epoch (Aquitanian), by which the Euphrates Formation was deposited...

2025, Tectonophysics

With the aim of obtaining Tertiary palaeomagnetic directions for the Adriatic Foreland of the Dinaric nappe system, we carried out a palaeomagnetic study on platform carbonates from stable Istria, from the northwestern and the Central Dalmatia segment of imbricated Adria. Despite the weak to very weak natural remanences of these rocks, we obtained tectonically useful palaeomagnetic directions for 25 sites from 20 localities. All exhibit westerly declinations, both before and after tilt correction. Concerning the age of the magnetizations, we conclude that five subhorizontal and magnetite bearing Eocene localities from stable Istria are likely to carry primary remanence, whereas three tilted and hematite-bearing ones were remagnetized. In the northwestern segment of imbricated Adria the cluster of the mean directions improved after tectonic correction indicating pretilting magnetization. In contrast, Maastrichtian -Eocene platform carbonates from Central Dalmatian were remagnetized in connection with the late Eocene -Oligocene deformation or Miocene hydrocarbon migration. Based on the appropriate site/ locality means, we calculate mean palaeomagnetic directions for the above three areas and suggest an alternative interpretation of the data of Kissel et al. [J. Geophys. Res. 100 (1995) 14999] for the flysch of Central Dalmatia. The four area mean direction define a regional palaeomagnetic direction of Dec = 336j, Inc= + 52j, k = 107, a 95 = 9j. From these data we conclude that stable Istria, in close coordination with imbricated Adria, must have rotated by 30j counterclockwise in the Tertiary, relative to Africa and stable Europe. We suggest that the latest Miocene -early Pliocene counterclockwise rotations observed in northwestern Croatia and northeastern Slovenia were driven by that of the Adriatic Foreland, i.e. the rotation of the latter took place between 6 and 4 Ma.

2025, Tectonophysics

The central-western and the eastern Southern Alps are separated by the triangular shaped Adige embayment, which belongs to stable Adria and was the site of pelagic sedimentation from the Tithonian through Maastrichtian. The first part of this study presents paleomagnetic results from the Tithonian-Cenomanian Biancone and Turonian-Maastrichtian Scaglia Rossa formations sampled at 33 geographically distributed and biostratigraphically dated localities. The new and high quality paleomagnetic results from the Adige embayment are then combined with coeval paleomagnetic directions from autochthonous Istria , which also belongs to stable Adria. The combined data set (which for the Late Albian-Maastrichtian time period is constructed similarly to the synthetic African curve by Besse and Courtillot, 2002, 2003) reveals an important tectonic event (Late Aptian-Early Albian) characterized by 20°CCW rotation and sedimentary hiatus. Comparison between paleomagnetic declinations/inclinations expected in an African framework (i.e. with the assumption that Adria is still an African promontory) leads to the following conclusions. The timedistributed Tithonian and Berriasian (150-135 Ma) paleomagnetic directions exhibit the "African hairpin" with an inclination minimum and a sudden change from CW to CCW rotation at 145 Ma. Concerning the younger ages, the declinations for Adria continue to follow the African trend of CCW rotation till the end of Cretaceous. However, the Tithonian-Maastrichtian declination curve for stable Adria is displaced by 10°from the "African" curve as a result of two rotations. The first, an about 20°CW rotation of Adria with respect to Africa took place between the Maastrichtian and the mid-Eocene. During this time the orientation of Adria remained the same, while Africa continued its CCW rotation. The younger rotation (30°CCW) changed the orientation of Adria relative to Africa as well as to the present North.

2025, …

Sedimentological and paleontological study of the Man Aike Formation at the Estancia 25 de Mayo, SW of Santa Cruz Province, Argentina, represents the evolution of an incised valley from fluvial to marine environment during the late middle Eocene. At the base of the unit there is an unconformity that corresponds to fluvial channels which cut down into the underlying Maastrichtian sandstones of the Calafate Formation. The fauna of invertebrates (mostly molluscs) illustrated herein was collected from shell beds interpreted as tidal ravinement surfaces. The fauna includes terebratulid brachiopods, bivalves of the families Malletiidae, Mytilidae, Pinnidae, Ostreidae, Pectinidae, Carditidae, Crassatellidae, Lahillidae, Mactridae, Veneridae, and Hiatellidae, and gastropods of the families Trochidae and Calyptraeidae, and a member of Archaeogastropoda of uncertain affinities. The similarities of this fauna with that recorded in the Upper Member of the Río Turbio Formation, together with 87 Sr/ 86 Sr ages, suggest a late Middle Eocene age for the Man Aike Formation.

2025

RESUMEN. En el sureste del lago Viedma afloran sedimentitas del Cretácico superior y Paleógeno de la cuenca Austral. En el perfil de Barrancas Blancas se describen 28 m de areniscas y fangolitas amarillentas correspondientes al Miembro La Asunción de la Formación Anita que son cubiertas en forma concordante y transicional por 390 m de areniscas y pelitas grisáceas de la Formación Cerro Fortaleza. Las primeras representan la progradación de ambientes de plataforma marina dominada por el oleaje mientras que las segundas atestiguan la sedimentación en ambientes transicionales, fluviales y fluviales con acción mareal. La evolución general de los paleoambientes sedimentarios y secuencias depositacionales, la procedencia de las areniscas y direcciones de paleocorrientes indican que estas rocas fueron depositadas durante la etapa de cuenca de retroarco (sag). En el cerro Pirámides se hallan presentes sedimentitas terciarias que se disponen en contacto tectónico sobre las rocas de la Formación Cerro Fortaleza. El escaso espesor preservado de las areniscas verdes de la Formación Man Aike (<1m) no permite un análisis detallado del paleoambiente de sedimentación. Por encima, en fuerte discordancia, se disponen 75 m de conglomerados, areniscas y pelitas, ocasionalmente carbonosas, correspondientes a la Formación Río Leona. Estas rocas son interpretadas como el registro de sistemas fluviales que rápidamente gradan desde alta a baja energía y que finalmente pasan en transición a más de 3 m de areniscas, fosilíferas, de ambiente marino litoral de la Formación Centinela. El arreglo de las litofacies y evolución de los paleoambientes sedimentarios, junto con la dirección de las paleocorrientes indican que estas rocas fueron depositadas durante la etapa de cuenca de antepaís.

2025

The main aim was to determine the composition, morphostratigraphy, provenance, sedimentary environment and age of the deposits using geomorphological, sedimentological, geochemical, mineralogical and biostratigraphical methods. Pliocene-Quaternary sediments were deposited in fluvial (braided and wandering river systems) and alluvial/colluvial fan environments. The sediments are preserved in the terrace staircase sequences, formation of which is strongly controlled by tectonic activity. Based on geomorphological analyses, low-, middle-and high-level terrace groups were constrained and tentatively attributed to Late Pleistocene, Middle Pleistocene, and Plio-Early Pleistocene, respectively. The provenance analyses focused on the Plio-Early Pleistocene sediments and included lithological and microfacies analyses of the clasts. Based on the provenance analyses and published data, the long-term development of the drainage network was interpreted. Major changes occurred during the transition from Miocene-Pliocene and at the latest at Plio-Early Pleistocene the drainage network reached conformity with the present one. Overall, the spatial distribution of the Pliocene-Quaternary landforms revealed tectonic activity in intramontane basins during their development, from which the landscape evolution was deduced.

2025, Science China-earth Sciences

Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanism of the Tibetan Plateau and their effects on climate, environment and life. Based on the extensive study of the sedimentary record on both sides of the Yarlung-Zangbo suture zone in Tibet, we review here the present state of knowledge on the timing of collision onset, discuss its possible diachroneity along strike, and reconstruct the early structural and topographic evolution of the Himalayan collided range. We define continent-continent collision as the moment when the oceanic crust is completely consumed at one point where the two continental margins come into contact. We use two methods to constrain the timing of collision onset: (1) dating the provenance change from Indian to Asian recorded by deep-water turbidites near the suture zone, and (2) dating the age of unconformities on both sides of the suture zone. The first method allowed us to constrain precisely collision onset as middle Palaeocene (59±1 Ma). Marine sedimentation persisted in the collisional zone for another 20-25 Ma locally in southern Tibet, and molassic-type deposition in the Indian foreland basin did not begin until another 10-15 Ma later. Available sedimentary evidence failed to firmly document any significant diachroneity of collision onset from the central Himalaya to the western Himalaya and Pakistan so far. Based on the Cenozoic stratigraphic record of the Tibetan Himalaya, four distinct stages can be identified in the early evolution of the Himalayan orogen: (1) middle Palaeocene-early Eocene earliest Eohimalayan stage (from 59 to 52 Ma): collision onset and filling of the deep-water trough along the suture zone while carbonate platform sedimentation persisted on the inner Indian margin; (2) early-middle Eocene early Eohimalayan stage (from 52 to 41 or 35 Ma): filling of intervening seaways and cessation of marine sedimentation; (3) late Eocene-Oligocene late Eohimalayan stage (from 41 to 25 Ma): huge gap in the sedimentary record both in the collision zone and in the Indian foreland; and (4) late Oligocene-early Miocene early Neohimalayan stage (from 26 to 17 Ma): rapid Himalayan growth and onset of molasse-type sedimentation in the Indian foreland basin.

2025, EGU General Assembly Conference Abstracts

2025, Marine Geology

wedge-top foreland basin (Pisuerga area, Cantabrian Zone, NW Spain)" by G.

2025, Sedimentology

A steep-margined carbonate platform is developed in the Carboniferous synorogenic foreland basin of northern Spain. Dips of 60±90°produced during Late Carboniferous thrusting enable cross-sections of a 4-km-wide portion of the marginal area of this platform (Las Llacerias outcrop) to be studied in aerial photographs at a seismic scale. Three stratal domains are observed: (1) a horizontal-bedded platform; (2) a clinoformal-bedded margin with a relief of up to 500 m; and (3) a low-angle toe-of-slope, where slope beds inter®nger with basin sediments. The slope shows well-bedded sigmoidal clinoforms with depositional dips ranging from 15°to 32°. Based on lithology and stratal patterns, four facies groups have been recognized: (1) a ¯at-topped platform, in which thick algal boundstone, skeletal packstone±grainstone and peloidal micrite wackestone with a poorly rhythmic character prevail; (2) the platform margin and upper slope, characterized by microbial boundstone spanning a bathymetric range of »150 m measured from the break of slope; (3) a slope, predominantly composed of margin-derived rudstones and breccias; and (4) a toe-of-slope to basin zone, where a cyclic alternation of spiculitic siltstones, packstone to grainstone calciturbidites and rudstone/breccia is visible. Five successive stages of platform development are deduced: (1) Bashkirian: ¯ooding of the pre-existing Serpukhovian platform giving rise to the nucleation of a low-angle ramp to the south-east of the study area with microbial mud-mound accumulations, and breccias and calciturbidites on the margins; (2) Early Moscovian: an in¯ux of siliciclastic sediment buried part of the platform and reduced the area of carbonate sedimentation; (3) Moscovian: aggradation and progradation of the carbonate system produced an extensive steep-margined and ¯at-topped shallow-water platform (shelf system); (4) Latest Moscovian±earliest Kasimovian: drowning of the platform; and (5) Kasimovian: covering of the platform by marly calcareous ramp sediments.

2025, Revista del Museo Argentino de Ciencias Naturales

Stratigraphic and taphonomic analysis of Bonitasaura salgadoi Apesteguía (Sauropoda, Titanosauria) at «La Bonita» site (Upper Cretaceous, Rio Negro Province, Argentina). «La Bonita» is a fossiliferous locality close to the town of Cerro Policía, Río Negro Province, Argentina. At the quarry are exposed siliceous rocks belonging to the Bajo de la Carpa and Anacleto formations (Santonian-Campanian), separated by an unconformity from the Renteria Formation (Upper Pliocene-Pleistocene). The Bajo de la Carpa Formation is composed of sandstones, fine beds of conglomerates, alternate with pelites and wackes beds. The Anacleto Formation is composed of sandy to pelitic beds. The Renteria Formation is dominated by conglomerates with clasts that reach 15 cm in length, included in a sabullitic matrix. The facies analysis suggests a fluvial regime, with a subacuatic control with changes from mid to low energy. The lenticular-shaped sandy channels with crossed stratification point to an unidirectional flow in the transporting agent and bioclasts. The taphonomical analysis suggested that the dinosaur dies close to the river margins, being rapidly incorporated to the fluvial sediments that sepulted the specimen in successive events. The spatial distribution and bone relations suggest a very short transport from the source area, with a slight northward movement. The presence of two caudal vertebrae series with an opisthotonous articulation pattern, suggests that the animal was exposed long enough to permitt the rigor mortis and dissecation. The disarticulation degree also point to some amount of weathering of the skeleton before being sepulted. However, the exceptional periostium preservation in many cases suggests a very short subaerial exposure.

2025, Acta Geologica Polonica

Many geological problems have not been convincingly explained so far and are debatable, for instance the origin and changes of the Neogene depositional environments in central Poland. Therefore, these changes have been reconstructed in terms of global to local tectonic and climatic fluctuations. The examined Neogene deposits are divided into a sub-lignite unit (Koźmin Formation), a lignite-bearing unit (Grey Clays Member), and a supra-lignite unit (Wielkopolska Member). The two lithostratigraphic members constitute the Poznań Formation. The results of facies analysis show that the Koźmin Formation was deposited by relatively high-gradient and well-drained braided rivers. Most likely, they encompassed widespread alluvial plains. In the case of the Grey Clays Member, the type of river in close proximity to which the mid-Miocene low-lying mires existed and then were transformed into the first Mid-Miocene Lignite Seam (MPLS-1), has not been resolved. The obtained results confirm the formation of the Wielkopolska Member by low-gradient, but mostly well-drained anastomosing or anastomosing-to-meandering rivers. The depositional evolution of the examined successions depended on tectonic and climatic changes that may be closely related to the mid-Miocene great tectonic remodelling of the Alpine-Carpathian orogen. This resulted in palaeogeographic changes in its foreland in the form of limiting the flow of wet air and water masses from the south and vertical tectonic movements.

2025, Precambrian Research

The Penokean orogeny began at about 1880 Ma when an oceanic arc, now the Pembine-Wausau terrane, collided with the southern margin of the Archean Superior craton marking the end of a period of south-directed subduction. The docking of the buoyant craton to the arc resulted in a subduction jump to the south and development of back-arc extension both in the initial arc and adjacent craton margin to the north. A belt of volcanogenic massive sulfide deposits formed in the extending back-arc rift within the arc. Synchronous extension and subsidence of the Superior craton resulted in a broad shallow sea characterized by volcanic grabens (Menominee Group in northern Michigan). The classic Lake Superior banded iron-formations, including those in the Marquette, Gogebic, Mesabi and Gunflint Iron Ranges, formed in that sea. The newly established subduction zone caused continued arc volcanism until about 1850 Ma when a fragment of Archean crust, now the basement of the Marshfield terrane, arrived at the subduction zone. The convergence of Archean blocks of the Superior and Marshfield cratons resulted in the major contractional phase of the Penokean orogeny. Rocks of the Pembine-Wausau arc were thrust northward onto the Superior craton causing subsidence of a foreland basin in which sedimentation began at about 1850 Ma in the south (Baraga Group rocks) and 1835 Ma in the north (Rove and Virginia Formations). A thick succession of arc-derived turbidites constitutes most of the foreland basin-fill along with lesser volcanic rocks. In the southern fold and thrust belt tectonic thickening resulted in high-grade metamorphism of the sediments by 1830 Ma. At this same time, a suite of post-tectonic plutons intruded the deformed sedimentary sequence and accreted arc terranes marking the end of the Penokean orogeny. The Penokean orogen was strongly overprinted by younger tectonic and thermal events, some of which were previously ascribed to the Penokean. Principal among these was a period of vertical faulting in the Archean basement and overlying Paleoproterozoic strata. This deformation is now known to have post-dated the terminal Penokean plutons by at least several tens of millions of years. Evidence of the Penokean orogen is now largely confined to the Lake Superior region. Comparisons with more recent orogens formed by similar plate tectonic processes implies that significant parts of a once more extensive Penokean orogen have been removed or overprinted by younger tectonic events.

2025, Swiss Journal of Geosciences

The study of the neotectonic activity in the Jura Mountains (northwestern most belt of the European Alps) represents a challenge in the application of quantitative geomorphology to extract landscape metrics and discuss potential coupling between tectonic, climatic and lithospheric mechanisms during the evolution of this mountain belt. The Jura Mountains are characterized by a karst calcareous bedrock, slightly affected by Quaternary glaciations, and by moderated uplift rates (\1 mm/year). In this study, we performed river profile analyses to decipher comparable geomorphological signals along tectonic structures within the entire Jura arc. Our results suggest higher tectonic activity in the High Range of the belt (internal part) than in the External Range, which is discussed in terms of deformation mechanisms. Integration of our results with previous geomorphological, neotectonic and geodetic studies from the literature leads us to propose new potential lithospheric and tectonic mechanism(s) driving the Plio-Quaternary deformation of the Jura Mountains. Our study finally reveals a regional-scale correlation between neotectonic deformations recorded by the Jura drainage network and the predicted isostatic rebound in response to Alpine Quaternary erosion. However, the correlation between our geomorphic signals and compressive structures suggests that the Jura Mountains could be still in horizontal shortening in both the High Range and the External Range.

2025, Earth and Planetary Science Letters

The investigation of deformation rates on a mountain piedmont can provide key information for improving our understanding of the overall dynamics of a mountain range. Here, we estimate the shortening rate absorbed by a Quaternary emergent detachment fold on the southeastern piedmont of the Tianshan (China). Our work is primarily based on new 10 Be cosmogenic exposure dating of deformed alluvial surfaces. The method we have developed combines depth profiling with sampling of surface cobbles, thereby allowing exposure time, erosion rate and inheritance to be simultaneously constrained. The exposure ages of the uppermost uplifted alluvial surfaces are around 140 ± 17 ka, 130 ± 9 ka and 47 ± 9 ka, from west to east. A terrace lying below the 140 ka surface is dated at 65 ± 5 ka. The ages of the uplifted and folded alluvial surfaces were then combined with estimates of shortening obtained using two distinct methods: (1) the excess area method, where sedimentation rates, extracted from magnetostratigraphic studies, are used to determine the amount of sedimentation after the abandonment of the river; and (2) a folding model derived from sandbox experiments. The late Pleistocene shortening rates are shown to be between 0.4 ± 0.1 mm/yr and 0.8 ± 0.5 mm/yr on the western part of the fold and 2.1 ± 0.4 mm/yr along its central part. The central part of the frontal Yakeng anticline therefore accommodates up to 25% of the total shortening currently absorbed across the whole Eastern Tianshan range (8 mm/yr). However, this situation seems to have prevailed for only the last 150 ka, as the shortening rate absorbed by this nascent fold was previously ten times slower. While the initiation of folding of the Yakeng anticline can be traced back to 5.5 Ma ago, the basinward migration of the active deformation front onto the Yakeng fold is a relatively recent phenomenon and appears to be diachronous from west to east, probably in relation to the tectonic activity of the folds in the hinterland.

2025, Geomorphology

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2025, Earth-Science Reviews

The Apennines-Sicilian-Maghrebian fold-and-thrust belt originated from the subduction of the Alpine Tethys and the later collision of drifted continental blocks against the African and Apulian paleomargins. From North to South, the Sicilian Fold-and-Thrust Belt (SFTB) is divided in four main tectono-stratigraphic domains: (1) the Calabro-Peloritani terrane, drifted from the European margin, (2) the remnants of the Alpine Tethys accretionary Wedge (ATW) related to the subduction of the Tethys, (3) the folded and thrusted platform (Panormide) and deep-water (Imerese-Sicanian) series of the offscrapped African margin, and (4) the African foreland (Hyblean). Unfortunately, apart from central Sicily (Catalano et al., 2013a), scarce quality seismic lines and outcrops of key tectono-stratigraphic units make the structure and dynamic evolution of the centraleastern part of the SFTB controversial. First, this study outlines through a review of the tectono-stratigraphic evolution of the central-eastern sector of the Sicilian orogen, the major remaining issues concerning: (1) the occurrence of inferred Alpine Tethys units far from the region where the remnants of the

2025, Comptes Rendus Geoscience

The structure and dynamic evolution of a mountain belt piedmont are controlled by strong interactions between tectonics, surface processes (erosion, sedimentation), and climate. Studying these couplings relies on detailed geometric and kinematic analysis of morphostructural markers (folds, faults, terraces, alluvial surfaces) and analysis of syntectonic sedimentation. To study quantitatively how these markers form, evolve and record deformation, we developed a new analogue modelling approach using a specific composite granular material. The originality stands in the simultaneous modelling of orogenic deformation mechanisms and erosion-transport-sedimentation processes, but also in the use of techniques allowing quantitative measurement of morphostructural evolution. This methodology opens new perspectives in the fields of geomorphology (relief dynamics), seismotectonics (study of active faults), and sedimentology (including sequential stratigraphy).

2025, Geotemas ( Madrid )

Las fallas normales y las zonas de relevo son comunes en contextos extensivos y juegan un papel importante en la distribución de sedimento. Este control está bien estudiado en condiciones subaéreas, pero no es así en condiciones subacuáticas, donde los estudios son escasos. En estos casos, la modelación numérica puede ser una buena herramienta para entender y complementar la sedimentación sintectónica. En esta contribución, se presenta un nuevo modelo numérico (que combina deformación tectónica con sedimentación clástica) para estudiar el relleno sedimentario en una cuenca extensiva y, concretamente, en la zona de relevo entre fallas normales. Para este caso, se han definido diferentes configuraciones variando tres parámetros: (1) estructura; (2) tasa de desplazamiento de las fallas; y (3) localización del área fuente. La comparación entre los diferentes experimentos permite concluir que, la configuración estructural condiciona la sedimentación de los diferentes tipos de sedimento creando asimetrías en la distribución de sedimentos. Aún así, los correspondientes cinturones de facies (sedimento mayoritario) no reflejan esa asimetría y, por lo tanto, la posición de las fallas en profundidad. Además, la dirección de transporte condiciona el patrón de distribución llegando a obtener arquitecturas de depósito complejas con aparentes terminaciones estratigráficas que pueden inducir a errores interpretativos (terminaciones aparentes de estratos) en áreas sin información litológica.

2025, Palaeogeography, Palaeoclimatology, Palaeoecology

Proximal alluvial sediments represent a precious sedimentary archive to reconstruct the tectono-climatic history of continental rift basins. However, poor dating of coarse fluvial successions usually prevents high-resolution distinction of tectonic and climatic processes and good determination of process rates. This paper presents a multi-method approach to the dating of Plio-Pleistocene sediments of the Kalavryta river system, during the development of the early Corinth Rift (northern Peloponnese, Greece). This river system developed across several active normal fault blocks that are now uplifted along the southern rift margin. The detailed sedimentary record constrains alluvial architectures from the proximal basin to the river outlet where small deltas built into a shallow lake. In four magnetostratigraphy sections the correlation to the reference scale relies on the identification of the Gauss/Matuyama magnetic reversal and biostratigraphic elements. The river system developed between about 3.6 to 1.8 Ma, with SARs ranging from 0.40 to 0.75 mm yr-1. SAR is lower in the alluvial fans than in the deltaic system, and higher at the centre of the normal fault depocentres than at the fault tip. By comparison with worldwide Cenozoic SARs based on magnetostratigraphy, our values are high but lie in the same range as those determined in coarse alluvial foreland basins. Moreover, in the context of overfilled intra-mountainous rift basins, these rates are minimum values and can be used as a proxy for accommodation rate. Therefore, early rift stratal wedges and growth synclines attest high sedimentation rates and also high rates of tectonic processes. Finally, in the distal river system, floral compositions and changes of vegetation deduced from palynological data are coherent with alternating fluvio-deltaic and shallow lacustrine deposits, which are linked to relative base level variations. Dry/cool climate is preferentially recorded in mouth bars and deltaic plains deposits during periods of low lake level, while the warm/moist climate is recorded in prodelta deposits during periods of high lake level. This correlation suggests that, despite the dominant control of active faulting, climate is a key control of syn-rift stratigraphic architectures.

2025, Journal of Geophysical Research: Solid Earth

2025, Geologica …

ABSTRACT.A comparison of structural, geophysical, metamorphic, stratigraphical and sedimentological data suggests that the progressive deformation of the Brabant Massif, the Brabantian orogeny, is more diachronous than commonly thought.... more

2025, International Journal of Earth Sciences

The development of the Alpine mountain belt has been governed by the convergence of the African and European plates since the Late Cretaceous. During the Cenozoic, this orogeny was accompanied with two major kinds of intraplate deformation in the NW-European foreland: (1) the European Cenozoic Rift System (ECRIS), a left-lateral transtensional wrench zone striking NNE-SSW between the western Mediterranean Sea and the Bohemian Massif; (2) long-wavelength lithospheric folds striking NE and located between the Alpine front and the North Sea. The present-day geometry of the European crust comprises the signatures of these two events superimposed on all preceding ones. In order to better define the processes and causes of each event, we identify and separate their respective geometrical signatures on depth maps of the pre-Mesozoic basement and of the Moho. We derive the respective timing of rifting and folding from sedimentary accumulation curves computed for selected locations of the Upper Rhine Graben. From this geometrical and chronological separation, we infer that the ECRIS developed mostly from 37 to 17 Ma, in response to north-directed impingement of Adria into the European plate. Lithospheric folds developed between 17 and 0 Ma, after the azimuth of relative displacement between Adria and Europe turned counter-clockwise to NW-SE. The geometry of these folds (wavelength = 270 km; amplitude = 1,500 m) is consistent with the geometry, as predicted by analogue and numerical models, of buckle folds produced by horizontal shortening of the whole lithosphere. The development of the folds resulted in ca. 1,000 m of rock uplift along the hinge lines of the anticlines (Burgundy-Swabian Jura and Normandy-Vogelsberg) and ca. 500 m of rock subsidence along the hinge line of the intervening syncline (Sologne-Franconian Basin). The grabens of the ECRIS were tilted by the development of the folds, and their riftrelated sedimentary infill was reduced on anticlines, while sedimentary accumulation was enhanced in synclines. We interpret the occurrence of Miocene volcanic activity and of topographic highs, and the basement and Moho configurations in the Vosges-Black Forest area and in the Rhenish Massif as interference patterns between linear lithospheric anticlines and linear grabens, rather than as signatures of asthenospheric plumes.

2025, International Journal of Earth Sciences

2025, Geotemas ( Madrid )

Taiwan provides an unparalleled opportunity to investigate the influence of inherited structures of the continental margin in the development of a fold and thrust belt (FTB). There, the Luzon Arc is obliquely colliding with the Eurasian continental margin forming the Taiwan Orogen. For this study we combine surface geological mapping and balanced cross sections with Vp tomography modelling and earthquake hypocenters. The margin's and FTB's basement is defined as pre-Eocene rocks. We use a Vp of 5.2 km/s as a proxy for the interface between basement and sedimentary cover. The south-central FTB includes significant along-strike changes in structure and stratigraphy that may be correlated with active structures in the basement. N to S changes in seismic velocities are interpreted as basement highs and lows and these correlate with areas where changes in the structural grain of the FTB take place. Several seismicity clusters align along the borders of these basement blocks. We interpret these features to indicate that basement is involved in the deformation and that the seismicity is imaging the reactivation of basement faults that influence the structure of the FTB.

2025

The Taiwan orogen forms an active mountain range that has been evolving since the Late Miocene as a result of the oblique collision between the Luzon Arc, located in the Philippine Sea Plate, and the continental margin of the Eurasian Plate. Due to this configuration, some inherited structures from the continental margin are at high angle to the structural trend of the Taiwan thrust-and-fold belt and are thought to play an important role in present day tectonics. The inherited structures resulted from processes undergone by the Eurasian margin, such as rifting in the Early Eocene, and further local extension in the Middle Miocene. They comprise sub-vertical faults that are presently being reactivated and are actively involved in the evolution of the structure, seismicity and topography of Taiwan, causing transverse zones in its thrust-and-fold belt and foreland.

2025, Geomorphology

The Parque Nacional Torres Del Paine and surrounding area in the Magallanes foreland basin in Chilean Patagonia is the site for numerous lakes fed by glaciers and rivers in the Andean highlands to the west. The lakes are elongate and have conspicuously systematic orientations. We hypothesize that the origin of the oriented lakes lies in the fault system, composed of a right-lateral strike-slip fault set oriented 58°from north, a left-lateral strike-slip set oriented 87°, and a thrust fault set oriented 167°, that exists within the underlying rocks. To test this hypothesis quantitatively, we determined the shape and orientation of the lakes by fitting each lake with an ellipse of appropriate aspect ratio, and later with multiple ellipses consistent with the composite geometry of some lakes. We then examined the faults in the area in terms of their kinematics, orientation and distribution. The distribution of lake orientations showed three distinct groups which appear to correspond to the three main fault groups. For lakes fitted with multiple ellipses, the difference in means between the right-lateral, left-lateral, and thrust faults and their corresponding groups of lakes are 3.05°, 1.57°, and 5.17°. Using a Kolmogorov-Smirnov (K-S) statistical test to compare the orientations of faults with respect to the lakes suggests that there is not a strongly significant difference between the fault orientations and the corresponding lake groups. These results indicate that the faults have a profound control on the orientation, shape, and distribution of the lakes. We attribute this to faults and their damage zones being weaker and therefore prone to a faster rate of erosion, and to stress perturbations associated with discontinuous faults resulting in localized high density fracturing and surface subsidence. These results have implications for lake and drainage system morphologies in other foreland basins along the Andes and other similar settings.

2025, Geologické výzkumy na Moravě a ve Slezsku

A thin veneers of coarse gravel deposits (clast size up to > 15 cm) are preserved on many summits of the Dyje–Pulkau watershed upland on the Carpathian Foredeep surface near the Bohemian Massif in the area, where the Waitzendorf fault parallels the boundary between both the large geological units. Related rim of the latter unit is there topographically manifested by the current prominent marginal slope mostly developed in granitoids of the Dyje Massif. In the existing maps and corresponding explanatory notes the northwestern occurrences of the gravel were considered, without direct stratigraphic evidence, as marine deposits of the Lower Badenian or uppermost Karpatian age (Lower/Middle Miocene transition). This paper revises the assumed genesis and stratigraphic position of the gravel based on pebble grain size and petrography analysis, assessment of geomorphological setting, and comparison with other gravel deposits in the vicinity characterized by some similar properties. The s...

2025, Geophysical Journal International

Current knowledge about deep crustal structure of the Alpine orogen has mainly been derived from P-wave velocity models obtained from active and passive seismic experiments. A complementary S-wave model to provide lithological constraints necessary for unique structural interpretation has been missing to date. In this paper, we present important new information on S-wave velocity model in the Alps. We applied the receiver function method using 6 yr of high quality data from 61 permanent and temporary stations sampling the Western-Central Alps. We determined first-order crustal features Moho depth (H) and average Vp/Vs ratio (κ) with the H-κ stacking technique that uses timing of direct and multiple P-to-S converted phases from the Moho interface. Synthetic tests reveal a dipping Moho interface, expected beneath an orogen, causes a systematic bias of H and κ potentially leading to misinterpretation. We thus applied corrections determined from synthetic data to remove the bias, providing better fit of recovered Moho depths with active seismic estimates. For each site, we also obtained independent H and κ estimates based on the timing of the strong Ps-phase. Our results show a gently south-southeast dipping European Moho at a depth of ∼24-30 km beneath the Northern Alpine Foreland, steepening rapidly towards the Europe-Africa suture zone to reach a maximum depth of ∼55 km. South of the suture, the Moho of the Adriatic crust, promontory of the African plate, is at ∼35-45 km depth. In the previously ill-constrained Western Alps, we found the European Moho at ∼30 km depth beneath the more external units dipping east-northeast to reach ∼50-55 km in the inner core of the Alps. The Poisson's ratio clearly correlates with the tectonic units that comprise the Alps. Average crustal values in the European Alpine Foreland are close to 0.25. In the Alps, we observe low values (0.22) in the highly deformed nappes of the Mesozoic Helvetic and Southern Alps indicating a thickening of felsic upper-crustal material. In contrast, the Poisson's ratio is significantly higher (0.26) in the Penninic and Austroalpine units near the suture zone. This rapid and significant change marks a clear rupture between the Alpine forelands and the suture domain. We assign this high Poisson's ratio to doubling of mafic lower crust consistent with results from previous active seismic experiments. A continuation of the lower crustal wedge into the central part of the Western Alps, however, seems unlikely based on low observed Poisson's ratios.

2025, Science advances

There is a considerable controversy about whether western Amazonia was ever covered by marine waters during the Miocene [23 to 5 Ma (million years ago)]. We investigated the possible occurrence of Miocene marine incursions in the Llanos and Amazonas/Solimões basins, using sedimentological and palynological data from two sediment cores taken in eastern Colombia and northwestern Brazil together with seismic information. We observed two distinct marine intervals in the Llanos Basin, an early Miocene that lasted ~0.9 My (million years) (18.1 to 17.2 Ma) and a middle Miocene that lasted ~3.7 My (16.1 to 12.4 Ma). These two marine intervals are also seen in Amazonas/Solimões Basin (northwestern Amazonia) but were much shorter in duration, ~0.2 My (18.0 to 17.8 Ma) and ~0.4 My (14.1 to 13.7 Ma), respectively. Our results indicate that shallow marine waters covered the region at least twice during the Miocene, but the events were short-lived, rather than a continuous full-marine occupancy o...

2025, Tectonophysics

Although numerous transfer zones of deformation have been observed in thrust wedges, their mechanisms and conditions of development are poorly understood. In this paper three basic questions are addressed: (1) what are the parameters controlling the genesis of transfer zones? (2) what are the kinematics of thrust propagation during transfer zone development? and (3) which kinds of geological structure link the two compartments on either side of the transfer zone? We attempted to solve these problems using a 3-D experimental approach. Sand models were used to simulate the foreland, a rigid, but mobile, backstop was used to produced a thrust Coulomb wedge which was studied during the various stages of its formation. Shortening led to the development of transfer zones in the wedge, separating two domains of homogenous behaviour and connecting thrust planes in different domains. The experimental results show that the development of transfer zones is controlled by mechanical and/or geometrical parameters such as: (1) variations in the sedimentary thickness in the foreland; (2) the steepness of the backstop; (3) domains with different basal friction in the foreland; (4) kinked backstop geometry. During deformation of the models, two types of thrust sequence were identified: alternative thrust propagations on both sides of the transfer zone and synchronous thrust propagations which are anastomosed within the transfer zone. 3-D reconstructions revealed that the thrust deformations observed in the transfer zone are oblique ramps. The frontal thrust bending of the Barbados accretionary complez, as well as the imbrication of thrust in the "Castellane" arc and the oblique ramp in the Zanskar Range, are discussed in relation to the mechanisms and structures revealed by the models. The results of analogue modelling suggest that the development of transfer zones is directly linked to variations in the boundary conditions (mechanical and/or geometrical) between two adjacent parts of a thrust wedge.

2025, Earth and Planetary Science Letters

Experimental modelling allows one to describe the development and kinematics of structures in mountain belts formed during oblique convergence. In the collision geometry of the Taiwan mountain belt, the Chinese continental margin is oriented about N60°E, whereas the N16°E Philippine Sea plate backstop is moving toward the Eurasian plate in the N55°W direction. Sandbox experiments have been conducted to simulate the Cenozoic arc-continent collision in Taiwan with a foreland-dipping backstop. The kinematics of deformation comprises a combination of compression and rotation which locally result in a partitioning between thrusting and wrenching. The experimental modelling shows that the faults or shear zones are rotated around the indentation point of the backstop by transcurrent and bookshelf faulting. An overall clockwise rotation (or right-lateral movements) occurs to the north of the indentation point and anticlockwise rotation occurs to the south of the indentation point. Oblique indentation and rotation structures can be demonstrated by (1) the crescent shape of the thrust wedge, (2) pull-apart structures induced by strike-slip tectonics, and (3) bookshelf-type strike-slip faulting resulting from the block rotation around the indentation point.

2025, Quaternary Geochronology

Fluvial, colluvial, and aeolian sediments were dated by optically stimulated luminescence (OSL) on quartz to improve the chronological framework for Quaternary sedimentation and landscape evolution in the forelands of the Ve ´rtes Hills (central Hungary). The separated quartz was suitable for age determination based on an OSL SAR protocol. Most samples have asymmetric equivalent dose distributions and OSL ages were calculated by the mean, central, and minimum D e values. Considering geomorphology and earlier age data from the area, the central D e values seem most appropriate for age calculation. A fan on the geomorphological level QV in the western foreland of the Ve ´rtes Hills was deposited 79-75 (AE8) ka ago. In the south-eastern foreland an alluvial fan on level QIIb is at most 42 AE 4 ka old. Fluvial incision and aggradation occurred 16-10 (AE1) ka ago on the geomorphic surface QIIa. Loess is 14 AE 1 ka old, and slope sedimentation was active 11-9 (AE1) ka ago. Our OSL data demonstrate that in the north-western foreland of the Ve ´rtes Hills wind remained an important agent after the last glacial times, into the early Holocene (9-8 AE 1 ka) and was able to accumulate large aeolian dunes.

2025, Earth Surface Processes and Landforms

ABSTRACTSediment distribution is investigated applying grain size analysis to 279 surface samples from the transitional zone between high mountains (Qilian Shan) and their arid forelands (Hexi Corridor) in north‐western China. Six main sediment types were classified. Medium scale (103 m) geomorphological setting is carefully considered as it may play an important role concerning sediment supply and availability. A tripartite distribution of sedimentological landscape units along the mountain to foreland transition is evident. Aeolian sediments (e.g. loess and dune sands) are widespread. They are used to identify aeolian transport pathways. The mU/fS‐ratio (5–11 µm/48–70 µm) among primary loess opposes the two grain size fractions being most sensitive to varying accumulation conditions. The first fraction is attributed to long‐distance transport in high suspension clouds whereas the latter represents local transport in saltation mode. The ratio shows strong correlation with elevation...

2025, GeoArabia

ABSTRACTOn the basis of structural style and differences in Late Cretaceous evolution, the carbonate platform in northern Oman and the allochthonous wedge comprising deepwater sediments and oceanic crust in the Oman Mountains form distinct structural domains. Imbrication associated with the emplacement of the Semail Ophiolite and predominantly SW-verging thrusting of the Arabian Platform margin culminated in the late early Campanian. The structural grain of NW-trending thrust faults and contractional folds contrasts markedly with the style and grain of the region immediately south of the Oman Mountains (our study area) and implies strong strain partitioning. Kinematic indicators from subsurface data, combined with the age of growth faulting, provide the basis for the interpretation that maximum horizontal stress was oriented NW-SE in this foreland region rather than NE-SW during the Campanian. The dominant tectonic control on the formation of faults is believed to have been an obliq...

2025, International Petroleum Technology Conference

This paper presents a new structural model for the North Kuwait Carbonate fields as well as its implications in term of fracture modelling and field development. It also describes a workflow which can be used as foundation for further fracture modelling study at production and exploration scales alike. This workflow consists of a four step approach: elaboration of a regional structural model,creation of 3D conceptual fracture diagrams,elaboration of constraints capturing the key elements of the conceptual diagrams andcreation of fracture model properties for further dynamic simulation. The application of this workflow resulted in the creation of a series of fracture models for the North Kuwait Carbonates fields. During the first step of the study, a new structural model has been elaborated based on key kinematic observations from well and seismic data, as well as experimental and field analogues which have been linked to the known regional phases of deformation. These main phases of...

2025, Revista Brasileira de Paleontologia

RESUMO -Duas estruturas sedimentares comparáveis a icnofósseis de metazoários foram descritas em rochas do Paleoproterozóico da Formação Cercadinho, Supergrupo Minas do Quadrilátero Ferrífero, Estado de Minas Gerais. As estruturas são perturbações parabólicas na laminação, perpendiculares ao acamamento de metarenitos com estratificações plano-paralelas a cruzadas tangenciais e acanaladas. A primeira, uma escavação semelhante a Skolithos ou Arenicolites, atinge 1,4 cm de largura e cerca de 4,5 cm de altura, com paredes nítidas e laminação interna desordenada; a segunda é comparável a um icnito de escape, com até 1,7 cm de largura e 6,7 cm de altura. A idade da Formação Cercadinho é bem restringida, entre 2,1 e 2,4 Ga, por uma série de dados geocronológicos e estratigráficos. A hipótese de que tais estruturas tenham sido produzidas por metazoários durante o Paleoproterozóico é incongruente com os registros fósseis mais antigos desse grupo. Outra possibilidade seria a de que essas estruturas não tenham origem orgânica e os processos que as formaram ainda sejam desconhecidos. Entretanto, experimentos preliminares, efetuados em laboratório, revelam ser difícil a geração de feições semelhantes por processos abióticos.

2025, Clay Minerals

Compositional trends of the Cenomanian Belle Fourche Formation, a marine shale unit in the Western Canada Sedimentary Basin, have been investigated on a regional scale using bulk-rock geochemistry and mineralogy, clay mineral compositions and oxygen isotope geochemistry of shale and bentonite core samples. Smectitic illite-smectite found in the matrix of immature, hemipelagic samples is compositionally and isotopically consistent with an origin from low-temperature alteration of volcanic ash in the central Western Interior Seaway, where the basin received minimal detrital input. The origin of the more illitic matrix in the deeply buried, western, pro-deltaic shales can be interpreted in terms of either diagenetic ‘illitization’ of a smectitic precursor, or depositional mixing of abundant, detrital, illitic material with minor amounts of ashfall-derived smectite. It is concluded that: (1) documented silicate mineral reactions during deep diagenesis of the Belle Fourche Formation took...

2025, Journal of Structural Geology

The Tuscarora fold system (TFS) is located in the Pennsylvania salient in the foreland of the Valley and Ridge province. The TFS is imaged in high quality 3D seismic data and comprises a system of small-scale folds within relatively flat-lying Lower Silurian Tuscarora Formation strata. We characterize the TFS structures and infer layer parallel shortening (LPS) directions and magnitudes associated with deformation during the Alleghany Orogeny. Previously reported LPS data in our study area are from shallow Devonian and Carboniferous strata (based on outcrop and core analyses) above the shallowest of three major detachments recognized in the region. Seismic data allows us to characterize LPS at depth in strata beneath the shallow detachment. Our LPS data (orientations and inferred magnitudes) are consistent with the shallow data leading us to surmise that LPS during Alleghanian deformation fanned around the salient and was distributed throughout the stratigraphic section -and not isolated to strata above the shallow detachment. We propose that a NW-SE oriented Alleghanian maximum principal stress was perturbed by deep structure associated with the non-linear margin of Laurentia resulting in fanning of shortening directions within the salient.

2025, Archaeologia Polona

The article raises the issue of the nature, intensity and environmental conditions of the settlement processes occurring on the borderline of the loessic Sandomierz Upland and the sandyclay areas of the Iłża Foothills, between the end of the 6th and the beginning of the 4th millennia BC. The results of previously conducted research confirm the high settlement activity in these areas, throughout the period of development of the Danubian cultural groups. The obtained data document the phenomenon of the formation and functioning of the early-agricultural settlement centres in upland areas, located outside the range of compact loess cover, i.e. within ecological and landscape zones that diverge from the basic preferences of the Danubian communities, inhabiting the upland areas of the upper Vistula basin.