Abstract Salt tectonics provinces host numerous resources and are now targeted as potential areas of development for energy storage capacities such as underground storage in salt caverns. Sedimentary basins containing salt structures are common at passive margins where volcanic rocks, emplaced either during the lithospheric breakup or the post‐rift subsidence, are also widespread. The interplay between volcanics and salt structures has been observed at various scales but never at the crustal scale along an entire passive margin. We have used subsurface data (seismic reflection and well data) to investigate how the formation of a Large Igneous Province (LIP) influenced the development of a gravity‐driven salt system in the Espírito Santo basin (offshore Brazil). The data show that where the LIP is absent, a classical gravity‐driven salt system emplaced with updip extension, translation and downdip contraction. When approaching the LIP, the emplacement of the volcanics caused salt expulsion under the load of the volcanic complex resulting in contractional features with a continent‐ward vergence. It completely overprinted the former translational domain and further south from the LIP, salt expulsion under the load of the volcanic complex, allowed for the development of a regional salt canopy. Our results highlight that salt‐related features such as halokinetic sequences, salt wings, allochthonous salt sheets and flats and ramps at the base of salt sheets, also occur when salt meets lava and volcaniclastics.

Geological Carbon Storage (GCS) is an essential climate mitigation strategy, enabling the long-term storage of carbon dioxide (CO₂) in deep subsurface formations. Offshore Atlantic Canada offers significant potential due to favourable geology, extensive subsurface data, and infrastructure from past hydrocarbon development. Major sedimentary basins such as the Scotian, Jeanne d’Arc, and Orphan contain structural traps, thick saline aquifers, and effective caprock seals that are critical for secure CO2 storage. Successful GCS depends on robust geological modelling workflows that incorporate subsurface heterogeneity, trapping mechanisms, and containment integrity. This paper reviews the foundational components of geological models - structural, stratigraphic, geometric, and topological frameworks – combined with numerical simulators to predict plume migration, pressure evolution, and geochemical interactions. Modelling supports all project stages, from site screening to post-injection monitoring, and is guided by parameters such as capacity, injectivity, containment, and storage efficiency. International offshore analogs such as Sleipner, Snøhvit, Northern Lights, Tomakomai, and Porthos provide valuable lessons in infrastructure reuse, regulatory development, and public engagement. These projects highlight the importance of tailored monitoring and verification plans, hub-based infrastructure models, and early-stage demonstration projects to build public trust. Offshore Atlantic Canada faces unique challenges including complex structural geology, overpressure zones, and salt tectonics, necessitating detailed technical evaluation. Recommended actions include high-resolution geologic modelling, probabilistic capacity assessments, and the creation of a regional carbon storage atlas. As regulatory frameworks evolve and carbon management becomes increasingly urgent, offshore Atlantic Canada is well-positioned to become a leader in safe, large-scale geological CO₂ storage.

ABSTRACT In Tunisia, the Atlas basin represents a key area to investigate sedimentation’s tectonic control from the Tethys Ocean’s final rifting stages to the onset of its closure. In this study, conducted in the Central Atlas, we aim to understand the regional rapid variations in thickness and facies of the Upper Cretaceous strata. Our study integrates both surface and subsurface data including lithostratigraphic sections of key outcrops, land gravity data, 2D seismic sections, and well data. The applied methodology successfully allowed us to determine the timing and duration of unconformities and highlight the subsidence migration within the basin. Cretaceous tectonics mainly consist of extensional deformations that created grabens and half grabens, where subsidence was active. 2D seismic sections interpretation and subsurface mapping reveal that sedimentary strata infilling grabens are expressed by divergent reflectors i.e. onlap terminations. However, pinch-outs and unconformities are marked by toplap terminations, suggesting non-deposition and/or erosion. Major unconformity (TGU) is identified on top of the Upper Cenomanian-Early Turonian shallow-water rudist-rich Gattar carbonates. It outlines a clear inversion creating local exposed paleohighs on subsiding domains prior to the event, and characterized in seismic with toplap and onlap reflector terminations. An important erosion occurred on the created high lands and the eroded material that formed ‘the Rouana polygenic breccias’ is resedimented in half-grabens and grabens. Breccias infilling grabens suggesting a structural inversion event was fundamentally, controlled by syn-depositional E-W and NW-SE-trending faults. The structural inversion caused locally, a long time (~60My) hiatus in stratigraphy which appears to be enhanced by other tectono-sedimentary events, particularly salt tectonics.

ABSTRACTThis study aims to investigate the structure and petroleum habitat of salt‐related structures in the Kosyu–Rogov Trough, which is a part of the Uralian fold‐and‐thrust belt in the Timan–Pechora Basin. The structures produced by the upper Ordovician salt are thought to have a much wider distribution in the Kosyu–Rogov Trough and the adjacent Chernyshev Swell than was previously believed. The sedimentary cover of the Kosyu–Rogov Trough is decoupled along the salt layer, resulting in the long‐distance transfer of contraction in the post‐salt deposits. Based on an integrated interpretation of subsurface data, including 2D and 3D seismic surveys, two types of salt structures are recognised: (1) salt pillows and (2) squeezed diapirs. The salt pillows are distributed in the mildly disturbed central part of the Kosyu–Rogov Trough above the layer‐parallel flat of the salt detachment. The squeezed diapirs are clustered within the external part of the study area in the highly disturbed Chernyshev Swell, where the salt layer is passing into basin margin carbonate equivalents. The squeezing of the massive salt diapirs of the Chernyshev Swell has produced large, salt‐detached backthrusts in the external part of the Kosyu–Rogov Trough. The horizontal displacement of the backthrust can reach 15 km. Stratigraphic thinning over diapirs and angular unconformities indicate that the initiation of the salt tectonics preceded the onset of the Uralian collision shortening in the late Artinskian. Salt diapirism episodically influenced the facies distribution in the post‐salt deposits, predetermining the location of carbonate banks, reefs, oolitic shoals and karstified areas. The large thickness of the sedimentary cover has resulted in early hydrocarbon migration, peaking before the Uralian shortening. This explains why previous exploration projects targeting thrust‐related traps that postdated the main migration were largely unsuccessful. It is proposed that traps associated with long‐lived salt structures, which were able to receive a hydrocarbon charge during the peak of hydrocarbon migration, are of primary exploration interest.

ABSTRACT This study presents a new geological map of the Salinas de Rosío diapir (Basque-Cantabrian Basin, northern Spain), based on detailed fieldwork, interpretation of high-resolution topographic data, and integration of existing geological information. The diapir displays an elongated geometry and consists of Keuper evaporites with Upper Triassic – Lower Jurassic carbonate intrasalt blocks and dolerite bodies. It pierces a Lower Cretaceous to Miocene sedimentary sequence, including marine and continental deposits variably affected by halokinesis. Structural and stratigraphic data from the overburden and the detailed mapping of progressive unconformities, indicate a multi-episodic history linked to extensional and contractional tectonics. The last stage of this evolution took place during the Miocene, under syntectonic Alpine compression, when accelerated salt rise and extrusion led to the formation of a characteristic salt glacier. This study highlights the value of detailed geological mapping and field-based structural analysis in advancing the understanding of salt tectonics.

Evidence for triassic salt tectonics in the meridional tellian Atlas: Example from the Ouled H'daïm diapir, Northern-central Algeria

Abstract Palaeogene depositional systems in the South Pyrenean foreland were influenced by eustatic sea level changes, compressive and salt tectonics, as well as biotic and environmental changes during and after the Palaeocene–Eocene Thermal Maximum (PETM). Decoupling these factors requires careful sedimentary and stratigraphic analysis. This study combines outcrop observations and microfacies analysis to derive a depositional model and to evaluate the relative roles of eustasy, tectonics and skeletal biota during deposition of the lower Eocene Alveolina Limestone, which immediately post‐dates the PETM. The studied succession is preserved in the footwall of the Montsec thrust. Diagnostic skeletal grains show a systematic upward change from coastal (miliolid foraminifera, charophytes) and inner ramp (miliolid and alveolinid foraminifera), through tidal bars or dunes (alveolinid and nummulitid foraminifera), to middle ramp (bryozoans, echinoderms, encrusters—mainly acervulinid foraminifera and coralline red algae) environments, a deepening succession recording the global early Eocene transgression. A condensation interval rich in red algae, iron and glauconite grains and cement marks the maximum flooding and passage to the overlying tidally‐influenced Baronia Formation sandstones. The fossil assemblage is consistent with expansion of foraminifera at the expense of corals in the aftermath of the PETM. Lower accommodation space and higher detrital input in the footwall of the Montsec thrust caused stratigraphic thinning and interbedding of carbonate debrites and sandstones. This suggests that the Montsec tectonic structure was at least partially emergent already during the earliest Eocene. Uplift of the Montsec tectonic structure, which was probably related to salt movements and compressive tectonics, and the early Eocene transgression facilitated a detrital provenance shift from a southern provenance in the Palaeocene to north/northeasterly Pyrenean sources. The large tidal bedforms in the Alveolina Limestone, deposited by currents amplified in a narrow strait, may provide evidence for the development of an Atlantic‐Mediterranean seaway.

The article discusses the problems of fixing wells in salt-bearing sediments. Research by domestic and foreign specialists in this area has been conducted since the middle of the 20th century, however, the problem of the quality of well anchoring in salt-bearing sediments has not been completely solved and remains relevant to the present. The article presents the causes of complications that occur during and after the attachment of wells, associated with plastic deformation of rocks and violation of the integrity of the casing. The specifics of salt-bearing deposits due to various factors are considered: — geological — spatial arrangement, chemical composition of rocks. During the implementation of the salt compressibility mechanism, changes occur in the sediments associated with the active activity of the accumulated fluid. This leads to the transformation of hydrodynamic and hydrochemical conditions and saturation of inter-salt layers with fluid;- tectonic – when exposed to salt tectonics and the mechanism of asymmetric compression of salt-bearing rocks is activated, loosening of inter-salt layers is formed during disorderly folding. All this contributes to an increase in the porosity and permeability of inter-salt formations due to the appearance of new cracks in them and the opening of old cracks. The movement of salt-bearing sediments under the influence of tectonic forces generates abnormally high pressures, leading to significant internal salt tectonics. The most intense tectonic fracturing is recorded in areas that have undergone maximum stress (the arched part of the structure, steep wings, and periclinal closure);- technological – the impact of drilling mud on the walls of the borehole can contribute to cavern formation, plastic deformation and destruction of rock, as well as fluid formation. At the same time, the weighting of the drilling fluid to create back pressure on the borehole walls can initiate new absorption complications, which are much more difficult to eliminate with simultaneous manifestation and absorption. Also, one of the favorable moments for the onset of plastic deformation of salts and fluid phenomena are lifting operations that cause sudden pressure drops. Methods for improving the attachment of wells in salt-bearing sediments are proposed.

Abstract Passive rifted margins comprise some of the largest and thickest (up to ∼4 km) salt basins in the world and exhibit some of the most complex salt tectonics. In the majority of these, the salt is deposited during the final stages of rifting, prior to continental breakup and oceanic spreading, with most of salt deformation occurring during the post‐rift. Post‐rift salt tectonics is controlled primarily by the differential load of supra‐salt sediments and the slope of the salt basin producing kinematically‐linked domains of deformation. Despite their similar geodynamic context and timing of salt deposition, salt tectonic evolution and structural styles vary significantly for salt‐bearing rifted margins. Our study aims to contribute to understanding what controls different types of salt structures developed along salt‐bearing rifted margins. We use 2D thermo‐mechanically coupled numerical forward models of rifted passive margin formation and salt tectonics to simulate late‐syn‐rift salt deposition and post‐rift salt deformation for different margin types. We focus on analyzing the geometry and dynamic evolution of individual salt structures and their controls along different margin domains for narrow, wide, and ultra‐wide rifted margins. Model results show that salt thickness, base‐salt relief and variations of sediment load are the overarching controls for the relative contribution of Poiseuille and Couette flow. This governs the effects of extension, shortening, vertical subsidence and diapir rise, which control the different types of salt diapirs, minibasins, faults, and rollover systems and their distribution along the margin.

The Mediterranean salt giant deposited during the Messinian salinity crisis (5.97−5.33 Ma) is the youngest known example of its kind on Earth. Unlike older layered evaporite sequences, which typically become gravitationally unstable and pierce through overlying formations, the Mediterranean salt remains relatively undeformed at shallow depths, with its internal stratification largely preserved due to minimal postdepositional deformation. This provides an opportunity to study the early stages of salt deformation. Still, the restoration of a repeatedly deformed multilayered sequence remains a challenge, even when original stratigraphic markers are identified. To reconstruct the history of deformation, one needs to distinguish between the various deformation phases and restore the evolving structures in sequence. In practice, such a restoration is rarely possible because kinematic markers (vectors) are nearly impossible to observe after multiple overprinting deformation phases. The strength of this study is rooted in the comprehensive regional mapping of a diverse array of faults and fold crests across five stratigraphic levels. This detailed mapping revealed several dominant deformation groups, shedding light on the tectonic processes at play. By assuming that the gliding direction was approximately perpendicular to the azimuth of the faults and the fold crests, and that asymmetric verging folds hint at the direction of motion, we inferred the kinematic patterns. Additionally, our analysis of crosscutting relationships, truncation features, and variations in syntectonic thickness allowed us to reconstruct a chronological sequence of deformation events. This study identified and chronologically constrained multiple deformation phases of the Messinian salt in the Levant Basin, providing new insights into both syn- and postdepositional kinematics. Our basinwide analysis underscores the key roles of regional tilting, buttressing structures, and differential sedimentary loading in controlling salt flow. Based on an extensive three-dimensional seismic reflection data set, this work presents the first high-resolution salt tectonic analysis of its scale, advancing understanding of early-stage halokinesis and setting a benchmark for future global research in sedimentary basins.

Abstract Triassic clayey-evaporitic materials played an important role in the detachment of tectonic units when structuring the Betic Cordillera. In the Cambil sector (Jaén, southern Spain), Triassic outcrops of detrital-evaporitic materials and carbonates have been interpreted as a nappe ("Cambil nappe"). The great development of breccias with clayey-gypsiferous matrix within these materials may be related to an olistostromic unit of the Oligocene-Aquitanian. However, such a redeposit of Triassic materials in the Subbetic Zone during the Miocene is controversial. The geological mapping carried out in this study reveals the tectonic complexity of the area. Large blocks of different nature and age crop out throughout the sector. The identification of Muschelkalk carbonate units of diverse paleogeographic origin, based on the Triassic stratigraphy, implies structures undergoing displacements of almost one hundred kilometers. Largely brecciated bands would be related, in this context, to tectonic structures of brittle-plastic range developed on clayey-gypsiferous materials. Salt tectonics alone cannot explain these regional displacements; hence most of the described tectonic fabrics must be associated with the thrusting and strike-slip faulting of the Betic fold and thrust belt.

Abstract The Kolwezi area of the Democratic Republic of the Congo hosts world-class stratabound Cu-(Co) and U-(± Cu-Ni-Co-Pb-Zn) mineralization within large fragments (écaille) of Lower Roan Group units that are hosted in the regional Roan breccia. Long-debated genetic models for the development of these types of deposits include the development of tectonic mélanges, friction breccias, sedimentary mélanges, olistostromes, and halokinesis or salt tectonics. Compiled historical data and new data at K.O.V. mine, which is an amalgamation of the Kamoto-East, Oliveira, and Virgule mines, situated in the Kolwezi “klippe” or subbasin, has been reanalyzed and used in the construction of a new, fully constrained, implicit 3-D model of lithologies and major structures. This data, which spans approximately 80 years, includes diamond and reverse-circulation drilling, new structural and lithological mapping data, downhole televiewer data, and macrostructural logging. In-pit observations, combined with these new, fully constrained, implicit 3-D models, provide new insights into the geometry and genesis of these deposits and their encompassing volume. The Kolwezi subbasin, characterized by K.O.V. mine, resulted from gravity-driven mass transport processes, concomitant with sedimentary deposition within a progressively folded foreland basin during orogenesis. The final geometry of fragments is due to (1) features that were inherited from the fold-and-thrust belt in the hinterland; (2) features caused by incorporation and dismemberment of fragments throughout a regional Roan breccia, as they were shed into the foreland basin; and (3) large-scale juxtaposition and impingement of fragments, complicated by late-kinematic tightening of the Kolwezi subbasin, further dewatering of the pile, and possibly further remobilization of fluids and metals. Collectively, these features, typified by K.O.V. mine, indicate that the Kolwezi subbasin, the Tombolo subbasin, and book similar regions in the foreland constitute the localized, preserved remnants of an olistostrome that was deposited within a previously much larger foreland basin, ahead of an advancing, thin-skinned fold-and-thrust system, and against the Nzilo block on the western margin of the Lufilian arc.

Terrebonne Basin, Gulf of Mexico gas hydrate resource evaluation and 3-D modeling of basin-scale sedimentation, salt tectonics, and hydrate system evolution since the early Miocene

Revealing the Salt Tectonic Puzzle: Mesozoic Base of the Norwegian North Sea

The Great Peak of Ouarsenis (“Grand Pic de l’Ouarsenis”) shows a spectacular geological structure that has intrigued geologists for more than a century. A stratigraphic pile comprising the entire Jurassic and lower Cretaceous levels is completely overturned for several kilometers. Various geological interpretations have been proposed, all of them within the framework of the Cenozoic compressional events responsible for the building of the Tell-Rif orogenic system. Based on a review of literature and field data, we propose a new interpretation in which early Mesozoic salt tectonics plays a major role. Salt activity is perceptible at the end of the Liassic and the Dogger but the main event, leading to the overturning of the lithostratigraphic succession dates from the Early Cretaceous. We tentatively correlate this event with a renewal of the extensive activity along the southern margin of the Tethys. The structures are then accentuated in the Cenozoic during the inversion of the margin and the building of the Tell system. The integration of the Early Cretaceous rifting in the geodynamics of North Africa is discussed.

Proper geologic reservoir characterization is crucial for energy generation and climate change mitigation efforts. While conventional techniques like core analysis and well logs provide limited spatial reservoir information, seismic data can offer valuable 3D insights into fluid and rock properties away from the well. This research focuses on identifying important structural and stratigraphic variations at the Mississippi Canyon Block 118 (MC-118) field, located on the northern slope of the Gulf of Mexico, which is significantly influenced by complex salt tectonics and slope failure. Due to a lack of direct subsurface data like well logs and cores, this area poses challenges in delineating potential reservoirs for carbon storage. The study leveraged seismic multi-attribute analysis and machine learning on 3-D seismic data and well logs to improve reservoir characterization, which could inform field development strategies for hydrogen or carbon storage. Different combinations of geometric, instantaneous, amplitude-based, spectral frequency, and textural attributes were tested using Self-Organizing Maps (SOM) to identify distinct seismic facies. SOM Models 1 and 2, which combined geometric, spectral, and amplitude-based attributes, were shown to delineate potential storage reservoirs, gas hydrates, salt structures, associated radial faults, and areas with poor data quality due to the presence of the salt structures more than SOM Models 3 and 4. The SOM results presented evidence of potential carbon storage reservoirs and were validated by matching reservoir sands in well log information with identified seismic facies using SOM. By automating data integration and property prediction, the proposed workflow leads to a cost-effective and faster understanding of the subsurface than traditional interpretation methods. Additionally, this approach may apply to other locations with sparse direct subsurface information to identify potential reservoirs of interest.

Abstract On 27 March 2021 a 3‐months lasting seismic sequence struck the Central Adriatic Basin that is part of the Adria plate, a relatively undeformed plate since recent times. Analyzing the waveform data acquired by the Italian and Croatian seismic networks, we computed the location parameters of 160 earthquakes and the focal mechanisms of the Mw 5.2 mainshock and the larger aftershocks. Most events align along a WNW‐ESE trending, 30 km long, narrow belt. The depth distribution of events indicates that the mainshock and a few aftershocks occurred within the upper 4 km, while most aftershocks were located below 5 km within the carbonate platform. We propose that the evolution of the 2021 earthquake distribution is primarily ruled by the top ductile salt layer. Moreover, the presence of a salt layer explains the relatively high VP/VS ratio of 1.83 in the sediment rocks surrounding the salt bodies, as also observed in similar tectonic settings. We suggest that the seismogenic fault likely responsible for the 2021 events is an inherited SW‐dipping normal fault, reactivated by reverse kinematics in response to the regional compressive stress. These results, and the understanding that salt deposits play a key role in focusing deformation and seismogenesis, represent a novel contribution to the long‐standing challenge of seismic hazard assessment of the Central Adriatic Basin, where moderate to large events could have devastating impacts along the densely populated coasts.

The North Caspian Basin, known for its oil and gas potential, was formed because of the evolution of the ancient Tethys Ocean and is also a result of the collision of the East European, Kazakhstania, and Siberian paleocontinents. At the beginning of the Mesozoic Era, it was a part of the northern continental margin of the Neo-Tethys, which formed Eurasia. In the Late Triassic and Early Jurassic, a major restructuring of the North Caspian sedimentary basin occurred, characterized by angular unconformity and the erosion of underlying sediments in the coastal zones of the basin. The sedimentary succession of the depression accumulating in the Mesozoic Era consisted of alternating siliciclastic and carbonate rocks. It began to form due to the destruction of the uplifts formed north and west of the East European craton and Urals, which resulted in coastal clastic material in the Triassic and Jurassic, but by the end of the Jurassic and Cretaceous, when all uplifts existing in the north of Tethys were leveled, it was mostly marine environments that contributed to the accumulation of siliciclastic and carbonate strata. The appearance of a large amount of sedimentary material towards the center of the depression, causing stress, as well as the deflection of the basement, contributed to fault tectonics and the resumption and manifestation of salt tectonics. As a result of the continuous diapirism of salt bodies during the Late Mesozoic, mini basins were formed, in which different sedimentogenesis was manifested. These processes contributed to the redistribution of hydrocarbons from the underlying pre-salt formations to the intermediate depth interval post-salt succession with Permian–Triassic and also near-surface Jurassic–Cretaceous formations.

Clinoform architecture influenced by salt tectonics and Quaternary Sea level changes: The Acheloos delta complex, Gulf of Patras, Greece

This paper investigates the structure and evolution of diapirism in the Ait Ourir Basin, located in the High Atlas of Morocco, using structural and sedimentological fieldwork integrated with field mapping. A tectonic-sedimentological study of the Mesozoic cover of the Ait Ourir Basin area revealed that these units were subjected to important saccadic halokinetic activity, reflected by anticline structures associated with regional faults that created several synclinal mini-basins. However, the absence of seismic coverage in the study area makes the proposed interpretation reliant on extrapolations from surface observations. In this work, we suggest that faults and salt activity led to the formation of different structures within the studied area. The growth of Triassic evaporites during various stages of the Mesozoic era is evident through the presence of both progressive and localized unconformities, each with distinct ages recorded. These geological features gave rise to elevated diapiric zones that saw reduced sedimentation, leading to abrupt lateral variations in thickness in multiple areas where this geological activity took place. This phenomenon is particularly well-documented in the mini-basins of Wanina and Jbel Sour, where a Senonian angular unconformity is clearly observed over the entire sedimentary cover, spanning from the Liassic to the Turonian period. The diapirism associated with the major faults, especially encountered between the basins, is often accompanied by late Triassic volcanic material. This diapir-fault relationship resulted in shallow and often depocentric zones in a pull-apart system within a distensive context.