Sequence stratigraphy has long provided a framework for deciphering how environmental conditions are recorded in sedimentary basins across a range of tectonic settings. Much of our current understanding of sequence architecture in depression basins, however, comes from studies that focus on individual external forcings such as sediment supply, climate, or lake-level change. The relative importance of these forcings in shaping key characteristics of stratigraphic patterns remains poorly quantified. Moreover, distinguishing external signals from autogenic variability is particularly challenging at mid-term (105–106 yr) timescales. To address these issues, we conducted nine numerical simulations of continental-scale sediment-routing systems, spanning millions of years, to examine how basin sedimentation and sequence stratigraphy respond to variations in lake level, precipitation and tectonic uplift within the source region of a depression basin. Our results show that different external forcings dominate distinct aspects of stratigraphic development: (1) precipitation strongly governs depositional and erosional rates, whereas uplift exerts only a minor influence; (2) uplift determines the overall extent of the basin margin, while autogenic processes introduce local spatial variability in its position; and (3) lake-level cyclicity controls stratal stacking patterns. A reduction in amplitude results in an earlier development of the initial flooding surface, which in turn extends the duration of transgression and increases the regressive ratio. Across all simulations, enhanced precipitation produces short, thick stratigraphic packages, whereas tectonic uplift generates more elongated, thin successions. These findings highlight the distinct signatures of different external forcings in shaping stratigraphic development and provide a basis for interpreting environmental signals preserved in continental depression basins, particularly over mid-term timescales.
This paper presents a new interpretation of an early Neoproterozoic cratonic basin. Its depositional history is a record of fault reactivation and differential subsidence in a heterogeneous basement during Rodinia's breakup. Globally, the reactivation of deep structures in older Proterozoic lithosphere surrounding the Archaean cratonic cores probably controlled the development of Neoproterozoic cratonic basins. These structures may also have provided conduits for mineralizing fluids. The Throssell Range Group (TRG) is a 1–3.5 km thick siliciclastic succession, topped by a carbonate platform, in the Paterson Orogen of north-western Australia. It hosts the c.2 Mt. Nifty Cu deposit. It is among several successions attributed to the large continental Centralian Superbasin, thought to have its origin in crustal sagging at c.840 Ma. However, the TRG includes deep water strata unusual for continental sag basins, and the ages of intrusions suggest that it is older than 840 Ma. Based on detailed logging of recent drillcore, two sedimentary sequences separated by a disconformity are recognised. This differs from previous work which interprets the TRG as a single conformable succession. Sequence 1 consists of three lithofacies associations, interpreted as the record of deposition in half-graben sub-basins, bounded by basement faults reactivated by extensional stresses related to Rodinia's breakup. Sequence 2 comprises four lithofacies associations, interpreted as recording a period of reduced clastic sediment supply in a peri-marginal continental basin exposed to wind-driven upwelling of nutrient-rich oceanic water. The subsidence of thin, more juvenile Proterozoic lithosphere produced a flooded margin between the Pilbara and North Australian Cratons. As sea level rise slowed, a carbonate platform prograded over the basin. More generally, this suggests that the Centralian Superbasin, and other Neoproterozoic cratonic basins, may best be thought of as mosaics of roughly coeval sub-basins, each with a specific history determined by local basement reactivation.
Major thickness changes of the Namurian interval (Serpukovian and early Bashkirian) recorded in wells across several basins in northwestern Europe provide indications for rifting, but little is known about the dynamics of this extensional phase. On the basis of new biostratigraphic analyses, well-log correlations, seismic interpretations, and geological models for the Campine Basin (northeastern Belgium), this study is the first to provide detailed constraints on the timing and geometry of this middle Carboniferous tectonic phase. The karstification of the lower Carboniferous carbonates, which is key for geothermal and gas storage applications in the region, was strongly influenced by the middle Carboniferous tectonics, highlighting the importance of a thorough understanding. During the early to late Visean, the Campine Basin was characterised by carbonate platform development under relative tectonic quiescence. The latest Visean was a time of major shifts in tectonics throughout Western Europe and marked the start of differential subsidence of the eastern Campine Basin. In this part of the basin, a several hundred meters thick sediment succession was deposited, with a progressive increase in siliciclastics at the expense of carbonates. In the western Campine Basin, in contrast, the latest Visean and earliest Namurian represented a major depositional hiatus. As differential subsidence continued from the Visean into the Namurian up to the earliest Westphalian A (late Bashkirian), the contemporaneous depositional sequences, mainly delta-systems, were consistently developed thicker in the eastern Campine Basin compared to the western Campine Basin. The regional thickness model of the Namurian, on the basis mainly of seismic data, indicates that the differentiation between the western and eastern Campine Basin took place along a narrow basin margin comprised of tilted blocks and faults with normal vertical throws having predominantly NNE–SSW orientations. This fault direction could have resulted from an ESE–WNW extensional direction that likely originated from N-S maximum horizontal compression by the northwards migrating Variscan thrust front further south. The extensional phase ended in early Westphalian A and marked the start of a thermal subsidence phase that likely continued up to the late Westphalian B when compressional foreland dynamics gradually started dominating the region. This transition from extension to thermal subsidence coincided roughly with a regional change in sedimentary deposition from delta progradation towards lower delta plain deposition.
The Pamplona Fault at the SE Basque-Cantabrian Basin is one of the most notable and controversial transverse faults of the Pyrenees. Previous studies of this structure have been based on the analysis of single geological and geophysical datasets, which has resulted in a variety of interpretations regarding its origin and role during the Mesozoic rifting and Cenozoic inversion of the Pyrenean orogen. In this study, a 3D model integrating all the geological and geophysical information available for the transition between the Basque-Cantabrian, Jaca-Pamplona and Ebro foreland basins has been built to provide an updated, comprehensive view of the Pamplona Fault. We have found strong conclusive evidence for its presence in the Palaeozoic basement, as part of a widespread NNE-SSW fault network that extends across the study area. Further evidence for the activity of the fault during the Mesozoic rifting derives from the geometry and sedimentary evolution of the overlying, allochthonous Cretaceous sedimentary units. Overall, our results indicate that the Pamplona Fault represented the easternmost boundary of the Basque-Cantabrian basin during Hauterivian-Barremian times, was active during the beginning of the hyperextension process that led to the eastward propagation of the basin across the fault during the Aptian-early Albian and acted as an accommodation structure during the rest of the Cretaceous. By the integration of these results with those from surrounding areas, we identify this fault not as a single structure but as a ~65 km-wide strip labelled Pamplona Transfer Zone that includes the neighbouring Hendaya and Oroz-Betelu faults and represented a diffuse transfer linkage between the Basque-Cantabrian and Mauléon segments of the Pyrenean rift. This wide transfer zone also exerted a clear role during the Cenozoic inversion of the rift, for it had an impact on the style of deformation and the local configuration of the Pyrenean thrust front.
Organic maturation and clay mineral-based estimates of the maximum paleotemperatures experienced by the Precambrian/Cambrian sediments on the East European Craton (EEC) are in disagreement. To resolve this conflict and reconstruct thermal histories of these sedimentary rocks we used three low-temperature thermochronometers: zircon and apatite (U–Th)/He (ZHe, AHe) and apatite fission track (AFT) methods, complemented by AFT modelling of thermal histories. At the cratonic edge (Podillya), the ZHe ages are partially reset, implying that the AFT ages are fully reset, and that the maximum paleotemperatures were in the range of 160°C–200°C, similar to earlier estimates based on the degree of illitization of smectite. Comparison with analogous data for the overlying Silurian bentonites identifies the edge zone of the former Devonian/Carboniferous Variscan foreland basin. In the Podillya region the modelling of thermal history of the Cambrian/Ediacaran strata indicated exhumation in Carboniferous time. In the cratonic interior (Volyn, Belarus, and Lithuania), the AFT ages are totally or partially reset, implying the maximum paleotemperatures close to 120°C, which confirm earlier estimates based on the degree of illitization of smectite, but are higher than the estimates based on the organic geochemistry. The relatively short mean confined tracks lengths (13.6 ± 0.4 to 10.8 ± 0.4 μm), and their varied standard deviation values (2.1–0.9) indicate slow exhumation within the partial annealing zone.
Mass-transport complexes (MTCs), the deposits of submarine slope failures and common features of sedimentary basins worldwide, can act as effective seals for hydrocarbons and carbon sequestration due to shear-induced overcompaction. However, seal failure is occasionally observed in specific parts of MTCs, leading to hydrocarbon and carbon dioxide leakage and posing potential threats to seabed stability. In this study, we combine 3D seismic and well log data from Qiongdongnan Basin, northern South China Sea, to investigate the mechanisms that influence and control the seal potential of MTCs. We identified three vertically stacked MTCs overlying a gas hydrate bearing interval. Seismic interpretation reveals that MTCs seal tends to fail in intervals where MTCs overlies the frontal ramp or remnant block, whereas the remaining intervals effectively seal the underlying gas hydrate. Petrophysical analyses show that MTCs intervals overlying frontal ramps or remnant blocks exhibit significantly lower density and velocity, higher porosity and permeability, indicating reduced compaction in these intervals. Numerical simulations indicate that during MTCs emplacement, shear localisation normally develops in the lowermost part, forming a narrow (10%–20% MTCs total thickness), highly deformed basal shear zone. However, shear localisation is disrupted by the remnant block or frontal ramp, leading to low shear strain and thus low seal potential in MTCs intervals overlying the remnant block or frontal ramp. Therefore, we propose that shear localisation is a key mechanism controlling the seal potential of MTCs. Disruption of this process during emplacement can significantly compromise MTCs seal potential, with important implications for understanding hydrocarbon distribution and for assessing the feasibility of submarine carbon sequestration using MTCs as natural seals.
The search for natural hydrogen (H2) in sedimentary basins is gaining increasing recognition due to its environmental friendliness. Therefore, as an alternative energy source, natural hydrogen could address the issue of environmental challenges and participate in the energy mix necessary for the energy transition. Despite ongoing research, many uncertainties remain in H2 exploration, which is still at an early stage. In this work, we provide, for the first time, a numerical model of radiolytic natural H2 generation from the fractured basement based on the Taranaki Basin example (New Zealand). This approach uses conventional hydrocarbon exploration techniques, with some adjustments to properly reproduce the subsurface natural H2 behaviour. We calculated the potential radiolytic H2 generation rate to be approximately 10.3 mg/g/Ma. This value was used as a constant rate input in the model. Potential reservoirs within the possible optimal H2 preservation window (80°C–200°C) include the Tane formation sandstone, as well as the Taimana and Tikorangi carbonate formations. The model highlights that H2 mass concentration in water is higher along the faults and in interbedded sand facies of the Rakopi and Wainui formations, implying that hydrogen in solution could migrate both by diffusion and advection along these paths. The density inversion of the seal and the underlying reservoirs began at 9.4 Ma and 6.8 Ma in the Witiora and Taranga boreholes respectively, due to the northwestward progradation of the Mohakatino Formation. This inversion indicates a period during which hydrogen-saturated water could be trapped or experience delayed flow, potentially leading to the exsolution of supersaturated hydrogen into a gaseous phase. The Tane formation gas anomaly reported during the drilling could be due to the conversion of CO2 into abiotic CH4 via the Sabatier reaction at higher temperatures (> 200°C). Consequently, abiotic CH4 could be an accurate proxy for depicting natural H2 generation.
The permanent oceanic connection between the Jurassic Central Atlantic and the Cretaceous South Atlantic was only established with the late opening of the Equatorial Atlantic, but the timing of this event remained unclear due to a lack of geological dating. In 2023, the DIADEM oceanographic cruise conducted sampling of the Buteur Ridge, offshore French Guiana, by dredging and during a manned deep submersible (Nautile) dive. The Buteur Ridge belongs to the eastern rifted margin of the Demerara Plateau, formed during the Lower Cretaceous Equatorial Atlantic rift. It is a 7 km-long and 6 km-wide tilted block, located at a depth of 3750 m, where sedimentary records of the Equatorial Atlantic are outcropping, making it an ideal location for investigating the timing of this rift.
We integrate petrological observations, biostratigraphy, fission-track analyses of detrital apatites and zircons, and LA-ICP-MS U–Pb dating of authigenic apatites to reconstruct the sedimentary, diagenetic and thermal history of the sediments sampled on the Buteur Ridge.
Our results constrain the tectono-sedimentary evolution of the divergent margin of the Demerara Plateau, revealing a complex rifting history of the Equatorial Atlantic involving two distinct rifts. The onset of the first rift occurred between 130 and 125 Ma (Hauterivian), which is earlier than the previously proposed Aptian age. A second rifting then occurred during the Cenomanian, likely during the kinematic reorganisation between Africa and South America in the Equatorial Atlantic. This later rifting is evidenced on the Buteur Ridge by terrigenous sedimentation followed by telodiagenesis during basin inversion, likely related to normal fault reactivation and ridge uplift. We interpret the crystallisation of authigenic apatites, dated 93 ± 12 Ma, as a record of the subsequent onset of marine transgression at the end of this second rifting, likely not occurring after the Late Cenomanian (circa 93 Ma).
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