Basin Research - Volume 34, Issue 2, 2022

In contrast to former tectono‐stratigraphic models, the model presented here considers: the creation of new real estate owing to basement exhumation via detachment faults; the younging of the base of passive infill oceanward related to sequential localization of deformation; the existence of syn‐necking unconformities at distal margins.

One fundamental lesson from the last decade's research into rifted margins is that stratigraphic horizons cannot be simply correlated from the proximal into distal domain, which makes the interpretation of poorly calibrated and largely inaccessible distal margins difficult. In this contribution, we propose a new tectono‐stratigraphic model to help break through the proximal/distal interpretation frontier. After reviewing the scientific advances on rifted margins achieved during the last century, we describe the primary spatio‐temporal evolution of active deformation during rifting. We show that different rift domains are associated with specific (1) periods of active deformation; (2) tectonic structures and related stratigraphic architecture; (3) amounts of accommodation creation owing to specific ranges of horizontal widening and vertical deepening and (4) depositional environments. We demonstrate that the sequential localization of extension during rifting results in a younging of the base of passive infill (i.e. sediment deposited in a non‐tectonic setting) oceanward. We propose a panel of few to few tens of My time intervals related to specific tectonic events—our Tectonic Sequences—that may be correlated more or less easily and continuously across rifted margins. This study underlines the value of an iterative approach between fieldwork on fossil rifted margins and offshore geophysical studies, where field studies offer easy‐to‐access and high‐resolution calibration of dismembered rifted margin remnants, while geophysical studies provide comparatively low‐resolution imaging of entire, intact but largely inaccessible, rifted margins. It also highlights the necessity of jettisoning outdated dogma on rifted margins and changing our routines when interpreting seismic sections and outcrops.

How and when the Pamir formed remains an open question. This study explores Pamir tectonics recorded in a sedimentary section in the eastern Tajik Basin. A prominent lithofacies change that has been recognised regionally is assigned to the middle Miocene (13.5 Ma based on preferred magnetostratigraphic correlation). Closely following this change, detrital zircon U‐Pb age spectra and mudstone bulk‐rock εNd values exhibit a sediment source change from the Central to the North Pamir estimated ca. 12 Ma. At the same time, the stable oxygen and carbon isotopic values of carbonate cements show negative and positive shifts, respectively. Combined with previous studies in both the Tajik and Tarim basins, these results suggest that the North Pamir experienced a middle–late Miocene phase of deformation and surface uplift. This supports models proposing middle–late Miocene Pamir tectonism, and climate models implying that coeval Pamir orogenesis deflected Westerly moisture and affected Asian environments.

Synchronous shifts of sediment accumulation rate, mudstone bulk‐rock εNd, and carbonate cement stable oxygen (δ¹⁸O) and carbon (δ¹³C) isotopic values around 12 Ma indicate deformation and surface uplift of the North Pamir since ~12 Ma.

The formation of carbonate build‐ups associated with seafloor methane vents – where microbially mediated sulphate‐dependent anaerobic oxidation of methane produces alkalinity – is well documented in modern marine environments and in the geologic record. However, the triggering event(s) behind the processes leading to hydrocarbon disequilibrium, seeping and consequent deposition of seep‐carbonates remain poorly constrained. This contribution characterises the salinity, geochemistry and temperature framework of a suit of fluid inclusions from hydrocarbon‐derived seep‐carbonate veins, collected from the Marmorito Formation in the Monferrato Hills, NW Italy. The datasets yield evidence of three different precipitation events, which comprise porous structures composed of well bladed calcites and aggregated spherules of aragonite. Fluid inclusions analysis shows the presence of a heterogeneous entrapment of immiscible fluids proving the paleo‐dissolution of a suite of complex hydrocarbons, which have a wide range of closing temperature starting at ca. 60°C. These physical and chemical conditions are considered to indicate seep‐carbonate deposition driven by disequilibrium of hydrocarbon‐bearing compounds at temperatures much warmer than the background ambient bottom waters (ca. 1 to 5°C) due to the influence of the Late Oligocene to Early Miocene tectonic compression at the junction of the southern Alps and Apennines.

Micro‐thermometry and Raman analyses of fluid inclusions from seep‐carbonates. Deposition of seep‐carbonates in hydrothermal conditions over 100 °C along structural discontinuities. Link between tectonic active regions and destabilization of complex hydrocarbons.

Late to post‐Caledonian, Devonian extension remains unresolved in the SW Barents Sea, despite considerable knowledge from onshore Norway, East Greenland and Svalbard. We analyse intrabasement seismic facies in high‐resolution 3D and reprocessed 2D data to investigate evidence for Caledonian deformation and post‐Caledonian detachment faulting in the central SW Barents Sea. These results are compared to published potential field models and analogue field studies from onshore Svalbard and Bjørnøya, substantiating that structures inherited from post‐orogenic extension influenced the Late Paleozoic and Mesozoic basin evolution. The Late Paleozoic Fingerdjupet Subbasin is underlain by a NNE‐striking, ESE‐dipping extensional detachment fault that records a minimum eastwards displacement of 22 km. The detachment fault and associated shear zone(s) separate post‐orogenic metamorphic core complexes from the syn‐tectonic deposits of a presumed Devonian supradetachment basin. Spatial variability in isostatically induced doming likely governed Devonian basin configurations. Pronounced footwall corrugations and faults splaying from the detachment indicate eastward extensional transport. This ultimately led to two interacting but subsequent, east‐stepping detachments. Local reactivation of the detachment systems controlled the extent of Carboniferous carbonate and evaporite basins in the Bjarmeland Platform area. Further, the Mesozoic Terningen Fault Complex and Randi Fault Set testify to how the inherited Devonian structural template continued to control spatial localisation and extent of rift structures during subsequent periods of extensional faulting in the Fingerdjupet Subbasin.

Intrabasement seismic facies analysis in the central SW Barents Sea indicates the presence of two subsequent, east‐stepping detachment faults motivating exhumation of metamorphic core complexes.

During the Early Cretaceous, Australia was flooded by the epicontinental Eromanga Sea, deposits of which occur across the Great Australian Superbasin. However, the mid‐Cretaceous retreat of this shallow sea, and the resultant palaeogeographic and sediment distribution patterns, are poorly understood. This study chronicles the Eromanga Sea's northward regression through the Carpentaria Basin as captured in the sedimentary record of the Normanton Formation. We achieve this by integrating sedimentary facies analysis of cores from across the Carpentaria Basin with palynology, sandstone petrography and U‐Pb detrital zircon geochronology. Results indicate that the Normanton Formation was deposited between ca. 100 and 96 Ma, and that it represents a large, northward‐prograding, likely river‐dominated delta system. The unit's volcanoclastic nature is exhibited through abundant lithic volcanics and devitrified glass, with a prominent, near‐depositional detrital zircon population attributed to a proximal continental magmatic arc‐derived source hypothesised to parallel the eastern seaboard of Australia at this time. The Normanton Formation is temporally correlative with the lower‐middle portions of the similarly volcanoclastic Winton Formation in the Eromanga Basin, which drained southwards into the Cenomanian‐Santonian Ceduna River Delta system. However, Normanton Formation strata display subtly different provenance signatures and drainage patterns, indicating input from similar, but likely more northern source terrains than much of the contemporaneous Winton Formation. These sediments were unlikely recycled southwards into the Ceduna Delta like those of the Winton Formation; rather they drained northward following the retreat of the Eromanga Sea through the Carpentaria Basin, indicating a Cretaceous drainage divide between two river systems, with distinct northern and southern drainage catchments. The mid‐Cretaceous palaeogeography of eastern Australia is analogous to that of the Late Cretaceous Western Interior Seaway of North America, in which the retreat of a shallow epicontinental sea is marked by the rapid deposition and progradation of multiple large, geographically distinct clastic wedges.

Palaeogeographic reconstruction of mid‐Cretaceous (Albian‐Cenomanian) eastern Australia, illustrating the formation of discrete palaeodrainage systems and both the southward (via the Ceduna River) and northward draining of the Eromanga Sea.

Fault‐propagation folding can be a protracted process that occurs in multiple phases. Additionally, extensional growth folds accommodate a significant portion (10–40%) of the total extensional strain. Therefore, the four‐dimensional evolution of extensional growth folding can provide a record of fault growth and rift history.

Extensional growth folds form ahead of the tips of propagating normal faults. These folds can accommodate a considerable amount of extensional strain and they may control rift geometry. Fold‐related surface deformation may also control the sedimentary evolution of syn‐rift depositional systems. Thus, by examining the stratigraphic record, we can constrain the four‐dimensional evolution of extensional growth folds, which in turn provides a record of fault growth and broader rift history. Here, we use high‐quality 3D seismic reflection and borehole data from the SW Barents Sea, offshore northern Norway to determine the geometric and temporal evolution of extensional growth folds associated with a large, long‐lived, basement‐rooted fault. We show that the fault grew via the linkage of four segments, and that fault growth was associated with the formation of fault‐parallel and fault‐perpendicular folds that accommodated a substantial portion (10%–40%) of the total extensional strain. Several periods of fault‐propagation folding occurred in response to the periodic burial of the fault, with individual folding events (ca. 25 and 32 Myr) lasting a considered part of the ca. 130 Myr rift period. Our study supports previous suggestions that continuous (i.e. folding) as well as discontinuous (i.e. faulting) deformation must be explicitly considered when assessing total strain in an extensional setting. We also show that changes in the architecture of growth strata record alternating periods of folding and faulting and that the margins of rift‐related depocentres may be characterised by basinward‐dipping monoclines as opposed to fault‐bound scarps. Our findings have broader implications for our understanding of the structural, physiographic and tectonostratigraphic evolution of rift basins.

Sketch showing presumed pattern for the development of differential compaction folds above the TZA/CT in the Neogene sediments of NE Atlantic margin.

This paper evaluates previously proposed diagnostic criteria that can be used to determine whether or not there is active migration of the opal‐A to opal‐CT transition zone (TZA/CT). The criteria are based on the interpretation of 2D and 3D seismic surveys and are therefore geometrical. They involve an assessment of the relationship of the TZA/CT with polygonal fault systems, differential compaction structures and tectonic folds. The most robust evidence for an inactive ‘reaction front’ between opal‐A and opal‐CT bearing sediments is the discordance of the TZA/CT relative to present‐day isotherms. Any of these may be persuasive as diagnostic criteria for the upward arrest of the diagenetic transformation at a regional scale, but actual truncation of the TZA/CT at the modern seabed is definitive for arrested diagenesis. This study argues that diagenetic assessment based solely on a single criterion independently is not reliable as an indicator for the current state of a silica transition. As a conclusion, the analysed seismic/structural criteria should be synthesised to provide a more credible interpretation for silica diagenesis. The use of modern 2D and 3D seismic data for the reconstruction of the diagenetic history of opaline silica bearing sediments offers a new approach to the study of silica diagenesis at a regional scale.

The buildup of a continental rise and its morphological patterns depend on sediment transport and deposition via downslope slumps, turbidity currents, along‐slope contourites and other deepwater currents. These delivery mechanisms are central to source‐to‐sink reconstructions, yet untangling their individual roles is not straightforward. The current study focuses on the sink section of the Nile system at the northern Levant continental rise (eastern Mediterranean). During the Pliocene, fluvial systems from northern Africa and the Levant margin supplied sediments to the study area. This supply decreased significantly during the Quaternary because of two processes: (a) The aridification of North Africa made the Nile River the predominant contributor to the basin; (b) the topographic rise of the Levant landmass severely limited fluvial supply. Meanwhile, on‐going counter‐clockwise marine currents became the prevalent supply system to the Levant margin, and downslope sediment‐transport became the only source to the northern Levant continental rise, which became a significant sink of the larger Nile system. These conditions provide an excellent natural laboratory for understanding the individual role of downslope sediment‐transport processes in building a continental rise. This research is based on single‐channel sparker seismic data, multibeam bathymetry and four 7–8 m long piston‐cores collected over the northern Levant continental rise at water depths of 1200–1800 m, together with available multibeam bathymetry and industrial multi‐channel seismic reflection data. The results show a major depositional changeover during the Pliocene‐Quaternary transition from concordant aggradation to repeated deposition of >12 sediment wave subunits, interpreted as upslope migrating cyclic steps. Quantitative analysis of the sediment wave morphology at the seafloor and subsurface, along with core data, indicates that the immediate sediment source was the nearby shelf. The supply was regulated by basinward‐landward shifts of the shore‐parallel marine currents during lowstand‐highstand conditions (respectively). Hence, this case study highlights the connection between sea‐level change and sedimentation patterns on a continental rise.

This study isolates the shelf‐related sedimentary contribution to its nearby continental rise and shows how the deep‐sea continental rise buildup (>1 km deep) is tangled with tectonic and sea‐level alterations. The study integrates analysis of multibeam, seismic reflection, and core data. The direct shelf‐rise sedimentary connection is central for source‐to‐sink analyses worldwide. In the figure: multibeam‐derived bathymetry of the Levant margin and adjacent deep basin (easternmost Mediterranean) overlain by dip azimuth map of the seafloor, 200 m contours interval, yellow arrow—schematic trajectory of the Levant Jet System (LJS) flow along the shelf and upper slope, white arrows—fallout sediments that glide downslope and settle on the sediment waves area as unconfined turbidites, light blue arrows—erosional channels. Abbreviations: CS—Carmel structure, D—Dor slide, EC—erosional channels, P—Palmahim slide, SC—slope canyons. Numbers represent the morphological domainsdiscussed in the text.

The Cathaysian Coastal Mountains are thought to be an ancient high‐topographic feature that existed along the margin of South China. They are characterised by extensive Jurassic–Cretaceous magmatism; however, their formation mechanism and timing remains uncertain. In this paper, we present sedimentological and detrital zircon analyses from Cretaceous–Eocene strata and drainage sediments from Hainan Island. Our analyses show a change in provenance from a proximal Cathaysian Coastal arc source in Cretaceous strata to a widely distributed intra‐island granite source in the Eocene strata and modern river sediments. Reconstruction of the crustal thickness evolution for the South China margin from Eu/Eu*‐in‐zircon proxy shows significant crustal thickening during the Late Jurassic–Cretaceous, thereby suggesting the existence of the Cathaysian Coastal Mountains. Together with a compilation of detrital zircon U‐Pb ages in the northern basins of the South China Sea margin, we conclude that the Cathaysian Coastal Mountains extended from the Red River region to Taiwan along the South China margin during the Late Jurassic–Cretaceous and then collapsed/eroded from northeast to southwest during the Eocene–Miocene. This large mountain range supplied detrital sediments to the marginal basins in the northern South China Sea and formed a topographic barrier that prohibited moist Pacific air to reach the relatively arid inland area of South China during the Late Jurassic–Cretaceous.

The Cathaysian Coastal Mountains extended from the Red River region to Taiwan along the South China margin during the Late Jurassic‐Cretaceous and then collapsed/eroded from northeast to southwest during the Eocene‐Miocene.

Extensional processes can lead to complex crustal configuration depending on the mechanisms of lithospheric thinning and the impact of magmatic additions during rifting and breakup. In this context, we studied the Vøring volcanic passive margin offshore Norway. The evolution of the inner Vøring Margin is well explained by standard models of lithosphere extension. However, these models fail to reproduce key observations at the outer (volcanic) province such as regional uplift at the time of breakup and excess magmatism. Therefore, additional processes are required to explain these observations. Excess magmatism and uplift have been related to mantle processes such as the arrival of the hot Icelandic mantle ‘plume’ or small‐scale convection processes. Melt retention in the asthenosphere has also been proposed to explain uplift. At last, mantle phase transitions during extension may contribute to uplift. We present tectonic and thermal models of basin evolution along a seismic profile crossing the Northern Vøring Margin. The thermal and isostatic history of basins is constrained through time‐forward basin modelling based on an automated inverse basin reconstruction approach. Two scenarios are evaluated: The first one includes pronounced mantle stretching during the last late Cretaceous‐Paleocene rifting event, and the second one includes late Paleocene‐early Eocene mantle thinning, at the breakup time around 56–54 Ma. Models incorporating late Paleocene‐early Eocene mantle thinning and taking into account magmatic processes (melt retention and magmatic underplate) and mantle phase transitions satisfactorily reproduce the specific observations of the outer (volcanic) margin. This result supports the contribution of the hot Iceland plume on the evolution of the Vøring Margin. Our results also indicate that thin‐crust models can produce a partially serpentinized mantle beneath the highly extended parts of the Vøring Basin. However, this model fails to reproduce observations. This suggests that serpentinization can occur locally but could not explain the entire lower crustal body nature.

A tectonic model incorporating late Paleocene‐early Eocene mantle thinning and taking into account magmatic processes (melt retention and magmatic underplate) and mantle phase transitions satisfactorily reproduce the specific observations of the outer (volcanic) margin such as uplift at the time of breakup and abundant magmatism. This result supports the contribution of the hot Iceland plume on the evolution of the Vøring Margin.

The Matzitzi Formation is the stratigraphic record of a late Permian, anastomosing fluvial system that flowed in a ~ NNE‐trending extensional basin developed on top of the Caltepense belt, a transpressive belt formed along the Caltepec dextral fault. Three possible scenarios can be proposed for the formation of the Matzitzi basin. 1) The basin was formed as a manifestation of the Caltepec fault late activity, which caused local NW–SE extension along the western margin of Pangea during its final assembly. 2) The basin was formed by slab rollback along the western equatorial Pangea margin. 3) The basin was formed in the framework of Pangea breakup. In this case, our data would suggest that Pangea breakup initiation must be dated back to late Permian time, which is ~ 15 m.y. older than the Middle Triassic age documented by previous work.

The breakup of Pangea fundamentally shaped modern continents and controlled the climatic distribution and biodiversity on Earth. Although our knowledge on the processes that control the assembly and breakup of supercontinents has significantly improved, the timing of supercontinent assembly and breakup initiation remains in some cases controversial. According to the available data, the assembly of Pangea was completed in middle Permian time, resulting in the formation of major orogenic belts and transform faults like the N–S‐trending, dextral, Caltepec fault in Mexico. Pangea breakup initiation is bracketed to early Middle Triassic time. In this work, we present new sedimentological, structural and U‐Pb geochronological data from a fluvial unit, the Matzitzi Formation of southern Mexico, the age and tectonic setting of which have remained an enigma for the past century. Our data document that the Matzitzi Formation is the stratigraphic record of a late Permian, anastomosing fluvial system that flowed in a—NNE‐trending extensional trough developed on top of the Caltepense belt, a transpressive belt formed along the Caltepec fault. We propose and discuss three possible scenarios for the tectonic setting of the Matzitzi Formation. In the first scenario, the unit is the stratigraphic record of the Caltepec fault late activity, which caused local NW–SE extension along the western margin of Pangea during its final assembly. In the second scenario, the Matzitzi Formation was deposited in an extensional basin formed by slab rollback along the western equatorial Pangea margin. In the third scenario, the extensional basin of the Matzitzi Formation was formed in the framework of the Pangea breakup. In this case, our data would suggest that Pangea breakup initiation must be dated back to late Permian time, which is ca. 15 m.y. older than the Middle Triassic age documented by the previous work. Considering that evidence of Permian extension has also been reported along the Appalachian belt, we suggest that the Matzitzi Formation was deposited during regional‐scale extension of western equatorial Pangea; therefore, we preliminarily support the third scenario. The distribution of Permian extension along suture belts developed during Pangea assembly highlights the fundamental role played by pre‐existent zones of weakness in the breakup of a supercontinent.

Oblique‐slip faults, which are essentially reactivated pre‐existing fault caused by non‐coaxial stress, are common in rift basins. Large faults with lengths exceeding thousands of kilometres are mostly rooted faults and would have experienced numerous reactivations. Using 3D seismic and drilling data, we investigated the geometry, kinematic features, growth and linkage, and three‐dimensional evolution of the Nandagang fault system (NDGFS) on the Qinan Slope in the Qikou Sag, Bohai Bay Basin. A hybrid fault model incorporating a lengthening stage and a displacement accrual stage was used to analyse the growth and linkage of NDGFS. By using the throw/displacement backstripping approach, ratios of maximum displacement to fault length (Dmax/L) of the evolving NDGFS were also obtained to delineate faulting stages of the hybrid fault model. From the pre‐Cenozoic basement to the Quaternary strata, NDGFS comprises three fault systems separated vertically by two unconformities, namely the lower, the middle and the upper systems. On planar view, NDGFS encompasses three structural trending zones with variable vertical growth styles. The E–W and NEE–SWW trending zones are mainly dominated by growth faults, while the NE–SW zones are characterised by dip‐linkage faults. For NDGFS, both the middle and deeper fault segments experienced a two‐stage hybrid faulting and reached their final lengths in ca. 20%–30% less time than the usual faulting lifetime proposed by previous researchers. In contrast, the upper faults, especially the segments within the Neogene Guantao (Ng) and Minghuazhen (Nm) formations, only experienced a lengthening stage. The slip rates and the pre‐existing faults have strong influences on the duration that faults accomplished their lengthening stages. A Dmax/L ratio of 0.015 obtained from the evolving NDGFS is determined to be effective in delineating between the lengthening stage and the displacement accrual stage, which may have a broad application for normal faults in similar geological settings.

Throw‐strike projection of three fault systems of NDGFS in Qikou Sag, Bohai Bay Basin. Its growth process mainly follows the ‘hybrid model’ encompassing the lengthening and displacement accrual stages. The Dmax/L of 0.015 may be the limitation between two stages of normal faults in rifted basins.

The magma‐poor West Iberian Margin (WIM), as part of the Peri‐Atlantic alkaline province, records multiple evidence for intra‐plate post‐rift magmatism. Based on high‐resolution multichannel seismic data, this work discusses the presence of large volcanic and intrusive features in the Estremadura Spur, providing evidence for important magmatic activity during the drifting of the continental margin. Our observations reveal distinct voluminous fissure‐fed effusive sequences and the details of the 2800 m‐high Fontanelas compound volcano, including its external and internal architecture, secondary vents and associated lava flows, all of which were probably extruded at intermediate water depths. Numerous and morphologically diverse sills and sill complexes are also described, attesting to the presence of a Late Cretaceous shallow magmatic plumbing system in the area. Magmatism in this region is interpreted as having occurred during two main pulses and types of activity: (1) Coniacian to lower Campanian(?) age, characterised by fissural and fault‐controlled volcanism, which mostly extruded massive lobate/sheet lava flows; and (2) a second voluminous intrusive and extrusive event of mid to late Campanian age, which includes the intrusion of the Estremadura Spur laccolith and the prominent Fontanelas compound volcano with associated dendritic lava flows. The inferred volumes of the first fissure‐fed effusive event suggest a large eruption magnitude, comparable to some of the largest historical effusive eruptions. The second magmatic pulse led to the emplacement of discrete clusters of sills and sill complexes, as well as the construction of the ca. 2.8‐km‐high Fontanelas volcano, suggesting a syn‐rift structural inheritance that controlled the location of the Estremadura Spur Intrusion and the Fontanelas volcanic area. Altogether, a total volume of rock exceeding 1.452 km³ is estimated to have been emplaced or extruded in this region in a relatively short period, attesting to the prominence of the magmatism in this sector of the WIM.

3D depth perspective of lava flows associated with fissural magmatism preceding the build‐up of the Fontanelas compound volcanic edifice.

Integrating seismic interpretation facilitates the discernment of tectonostratigraphic evolution in the eastern Korean continental margin, East Sea. The sedimentary succession of this margin is divided into three major seismic units based on distinct unconformities. These unconformities and their associated seismic characteristics indicate that the eastern Korean continental margin has experienced four evolutionary stages through extensional and subsequent two‐phase tectonic inversions. Early Miocene back‐arc opening of the East Sea triggered the extension of NNW–SSE and N–S trending rifts, resulting in non‐marine to deep‐marine deposition of typical rift‐related linked sedimentological systems in the eastern Korean continental margin. In the early Late Miocene, changes in plate motion and the subduction mode of the Japanese island (NW–SE compression) caused the positive inversion of extensional fault‐bounded half‐grabens in the eastern Korean continental margin, and the Hupo Basin was likely created by the regional flexural response. During this depositional period, hemipelagic sedimentation accompanied by episodic gravity‐controlled slope failures was predominant in the deep‐water environment. The subsidence of the Hupo Basin was enhanced by crustal shortening (E–W compression) that was induced by subduction initiation at the western margin of the Ulleung Basin during the late Early Pliocene (ca. 3.8 Ma). At that time, sedimentary environment gradually became shallower with time and coarse‐grained terrigenous input into the Hupo Basin began so that shallow‐ to deep‐marine sedimentation occurred. In the Quaternary period, the uplift of the Hupo Bank and coeval subsidence of the Hupo Basin were maintained by continued compressive neotectonics. The shallow‐ to deep‐marine deposition continued, but greater quantities of coarse‐grained terrestrial sediment were transported into the Hupo Basin due to combined effects on tectonics and eustasy. Based on the tectonostratigraphic reconstruction developed in this study, we propose that the Hupo Basin is likely a Late Miocene–Quaternary compression‐related basin induced by crustal or thrust loading.

The proposed model indicates that the evolution of the eastern Korean continental margin is characterised by four stages through an extensional and subsequent two phases of inversion tectonics. The spatio‐temporal distribution of depositional systems was conditioned by episodic syn‐tectonic activities.

The competition between the impact of inherited weaknesses and plate kinematics determines the location and style of deformation during rifting, yet the relative impacts of these ‘internal’ and ‘external’ factors remain poorly understood, especially in 3D. In this study, we used brittle‐viscous analogue models to assess how multiphase rifting, that is changes in plate divergence rate or direction, and the presence and orientation of weaknesses in the competent mantle and crust, influences rift evolution. We find that the combined reactivation of mantle and crustal weaknesses without any kinematic changes already creates complex rift structures. Divergence rates affect the strength of the weak lower crustal layer and hence the degree of mantle‐crustal coupling; slow rifting decreases coupling, so that crustal weaknesses can dominate deformation localisation and surface structures, whereas fast rifting increases coupling and deformation related to mantle weaknesses can have a dominant surface expression. Through a change from slow to fast rifting mantle‐related deformation can overprint structures that previously formed along (differently oriented) crustal weaknesses. Conversely, a change from fast to slow rifting may shift deformation from mantle‐controlled towards crust‐controlled. When changing divergence directions, structures from the first rifting phase may control where subsequent deformation occurs, but only when they are sufficiently well developed. We furthermore place our results in a larger framework of brittle‐viscous rift modelling results from previous experimental studies, showing the importance of general lithospheric layering, divergence rate, the type of deformation in the mantle, and finally upper crustal structural inheritance. The interaction between these parameters can produce a variety of deformation styles that may, however, lead to comparable end products. Therefore, careful investigation of the distribution of strain localisation, and to an equal extent of basin depocenter locations over time is required to properly determine the evolution of complex rift systems, providing an incentive to revisit various natural examples.

We modelled 3D structural weaknesses and multi‐phase rifting with changing kinematics. Strain and topography analysis shows that fast rifting localizes deformation along the simulated central mantle weakness, and slow rifting along the oblique simulated crustal weaknesses, respectively. The final model structures are very similar, despite having a very different history.

We reconstructed the infill of the offshore sector of the Campi Flegrei caldera, integrating the individuated seismic units with the marine, pyroclastic and volcaniclastic sediments outcropping on‐land. Results allowed us to constrain the timing of ground motion related to caldera resurgence and fine‐tune the stratigraphic position of debated coastal eruptions.

Silicic calderas are volcanic systems whose unrest evolution is more unpredictable than other volcano types because they often do not culminate in an eruption. Their complex structure strongly influences the post‐collapse volcano‐tectonic evolution, usually coupling volcanism and ground deformation. Among such volcanoes, the Campi Flegrei caldera (southern Italy) is one of the most studied. Significant long‐ and short‐term ground deformations characterise this restless volcano. Several studies performed on the marine‐continental succession exposed in the central sector of the Campi Flegrei caldera provided a reconstruction of ground deformation during the last 15 kyr. However, considering that over one‐third of the caldera is presently submerged beneath the Pozzuoli Gulf, a comprehensive stratigraphic on‐land‐offshore framework is still lacking. This study aims at reconstructing the offshore succession through analysis of high‐resolution single and multichannel reflection seismic profiles and correlates the resulting seismic stratigraphic framework with the stratigraphy reconstructed on‐land. Results provide new clues on the causative relations between the intra‐caldera marine and volcaniclastic sedimentation and the alternating phases of marine transgressions and regressions originated by the interplay between ground deformation and sea‐level rise. The volcano‐tectonic reconstruction, provided in this work, connects the major caldera floor movements to the large Plinian eruptions of Pomici Principali (12 ka) and Agnano Monte Spina (4.55 ka), with the onset of the first post‐caldera doming at ca. 10.5 ka. We emphasise that ground deformation is usually coupled with volcanic activity, which shows a self‐similar pattern, regardless of its scale. Thus, characterising the long‐term deformation history becomes of particular interest and relevance for hazard assessment and definition of future unrest scenarios.

The Permian‐Triassic alluvial rift succession in the Horda Platform area is analysed to construct a refined depositional model. The study demonstrates how subsurface continental rift successions may be stratigraphically subdivided and correlated by integrating seismic and well‐log data in concert with conceptual models. Regional unconformities mark the top and base of the Permian‐Triassic succession, which is sub‐divided into six seismic stratigraphic sequences, delineated by erosional‐ and non‐depositional surfaces. The definition of seismic stratigraphic sequences is based on seismic facies trends and Gamma Ray log signatures. Time‐thickness maps combined with geometries in cross‐section display the depocentre development. During the Permian‐Triassic, the Horda Platform experienced faulting, shaping the Caledonian pre‐rift landscape into a series of N–S trending half‐graben basins, contemporaneous to a gradual climate change from arid in the Permian to humid in the latest Triassic. The basin underwent three phases of rifting during the Late Permian‐Middle Triassic: (1) disconnected heterogeneous depocentres with strain concentrated in the west; (2) depocentres expanded northward; and (3) mature half graben development with widely distributed strain. Vertical lithological changes in mudstone/sandstone dominance reflect varying rates of accommodation and sediment supply (A/S). Systematic A/S variation reflects strong climatic fluctuations, which controlled facies patterns during both tectonic quiescence in the Middle‐Late Triassic, and during syn‐rift sedimentation. The Permian‐Triassic tectono‐sedimentary development in the Horda Platform area provides valuable lessons on the influence of faulting on depocentre development, how the interplay between tectonic and climatic forcing is expressed in subsurface continental deposits, and aid the characterisation of reservoirs.

The Permian‐Triassic basin in the Horda Platform (northern North Sea) was filled by alluvial sediments during a syn‐ to post‐rift regime contemporaneous with a gradual change from arid to humid climate. The interplay between tectonics and climate controlled the rate of accommodation creation relative to the rate of sedimentation, reflected in the basin geometry, sand:mud ratio, and facies distribution. A stratigraphical subdivision and correlation is applied to the Permian‐Triassic rock‐sequence by integrating seismic and well‐log data in concert with classic tectonostratigraphic schemes.

Detrital zircon geochronology of the Albian lower Blackleaf Formation in southwestern Montana documents a sharp change in provenance along the shoreline of the Western Interior Seaway. The western, nonmarine, lithic sandstone has a Sevier belt provenance; the eastern, marine, quartz sandstone was sourced from the Appalachians of eastern North America.

The Lower Cretaceous Blackleaf Formation in southwestern Montana records sedimentation in the Idaho‐Montana retroforeland basin of the North American Cordillera. Regional‐scale sedimentology suggests that during Albian time southwestern Montana was partially flooded by an early marine incursion of the Western Interior Seaway during deposition of the Blackleaf Formation. We use sandstone petrography, large‐n (n = 600) U‐Pb detrital zircon geochronology and mixture modelling to determine the provenance of these strata. Our analysis suggests three distinct provenance groups: Group 1 sandstones occur in the eastern region of the study area, are quartz‐rich and have zircon age‐probability peaks of ca. 110, 160, 420–450, 1050 and 1160 Ma; these sandstones match with a primarily Appalachian provenance. Group 2 sandstones occur in the western region of study area, are lithic‐rich and have peaks of ca. 110, 160, 1780, 1840, 1920, 2080 and 2700 Ma; the primary source for these sandstones was exhumed lower‐middle Palaeozoic strata from the Idaho sector of the Sevier belt. Group 3 sandstones occur in the western region of the study area, are lithic‐rich and have prominent peaks of ca. 115, 170, 430, 600, 1085, 1170, 1670 and 1790 Ma; the primary source for these sandstones was exhumed Triassic‐upper Palaeozoic strata from the Idaho sector of the Sevier belt. Our provenance data record a sharp change that coincides with the western shoreline of the seaway, and we infer that it may indicate the position of an irregular, submarine forebulge depozone influenced by dynamic subsidence during a period of reduced thrusting in the adjacent fold‐thrust belt. Albian‐aged sediments in southwestern Montana were delivered by rivers with headwaters in the Sevier belt as well as transcontinental river systems with headwaters in eastern North America. In southwestern Montana, west‐flowing transcontinental fluvial systems were flooded by the Western Interior Seaway as it encroached from the north.

The Rukwa Rift Basin, Tanzania is regarded as a modern example of a cratonic rift zone despite complex polyphase extensional and episodic inversion structures. We interpret 2D seismic reflection data tied to wells to identify and describe structures controlling stratigraphic sequences (Late Carboniferous to Pleistocene) in two main segmented Rukwa Rift domains, A and B, which are controlled by the Chisi and Saza shear zones. Fault geometry and stratal patterns are illustrated in relation to their kinematic interaction with folds. Fold structures reflect both extensional and compressional deformation and were mapped with a particular interest for their helium potential. We illustrate fault bend folds, fault propagation folds and fault propagation monoclines that are related to extension events. Folds related to compression exhibit various structural styles reflecting at least two phases of episodic and widespread inversion. First, Early Jurassic inversion phase which involved multi‐faulted anticlines in the Karoo strata. Second, a mild and widespread inversion structures during the Pleistocene which are characterised by both symmetrical and asymmetrical anticlines styles. Taken together, the extensional and compressional fold structures, stratal juxtapositions and unconformities define stratigraphic packages that are widely distributed in the Rukwa Rift Basin, and form potential subsurface traps for helium‐nitrogen–rich gases, from which some seep to the surface, evidently documented in thermal springs across the region.

Helium and hydrothermal system in the Rukwa Rift Basin.