Basin Research最新文献

Submarine canyon and channel systems are the primary paths for sediment transport from platforms to deep-sea terminal depositional fans and are present on all continental margins. The temporal morphological expression of such systems should be documented in order to fully understand the development of these important sediment pathways. We utilise a 3D seismic dataset from the northern Shetland Platform to the southern Møre Basin region and map two regionally continuous seismic horizons. The dataset includes an early Eocene northward-oriented canyon-channel system that allows high-resolution mapping of erosion and sedimentation. The morphology of the system allows a subdivision of platform, upper, middle, and lower slope, and basin floor. It is further subdivided from east to west according to the degree of erosive maturity. The platform contains channel shapes and their fill stretching from the south towards the platform edge and upper slope, where dendritic canyon heads developed. Scars in the canyon sidewalls indicate slope failure as an important widening mechanism. The slope canyons progressively shallow and widen basinward. At the canyon exits, deepwater submarine channels developed and continued onto the basin floor. We document progressive filling and overspilling of channels towards the terminal fan. The filling of the channels that resulted in overbank deposition is likely due to a decrease in slope gradient leading to an increased deposition rate that exceeds the channel capacity. Post-depositional differential compaction of the clastic channel fill and the surrounding muddy sediments causes the channel fills to form elongated ridges that lead towards the terminal fan. It is further shown that the morphological elements observed in the canyon-channel system adjust towards an equilibrium profile with a shallower gradient. These detailed observations provide an enhanced understanding of how canyon-channel systems develop on active margins and how sediment transport pathways are influenced by the submarine equilibrium profile and post-depositional processes.

Comprehensive mapping of the stratigraphy and structures is essential when exploring basaltic reservoirs for CO₂ storage. A major task in analysing the storage potential of the reservoir is to bring all relevant geological data within a single framework for integration and joint interpretation. In this study, we illustrate how data integration facilitates an improved understanding of the geological evolution of the Faroe Islands, the North Atlantic Igneous Province, and how the data integration forms a foundation for future carbon capture and storage campaigns. We have integrated new and existing data including geological field observations, digital elevation models, digital outcrop models, lithological logs, seismic profiles, and bathymetry in a single, consistent, and quality-controlled toolbox. Two key findings are that (a) we have mapped stratigraphic markers in the central Faroe Islands across the islands, and there is no indication of large-scale strike-slip faults that offset the volcanic stratigraphy; (b) our analysis provides no clear onshore evidence of transfer zones in the Faroe Islands. We show that a high density of data and integration of data types across different vertical and horizontal scales is crucial for mapping the highly heterogeneous basaltic reservoir.

There are numerous studies analysing volcaniclastic supply to continental environments in distal areas from source volcanoes. However, there are few examples where large pumice fragments are mentioned in distal fluvial deposits. In this work, the Miocene synorogenic deposits of the Northern Patagonian Foreland (Chichinales and El Palo Formations) were studied. The deposits of the latter unit include pumice fragments with diameters of up to 30 cm that were accumulated in a fluvial environment more than 200 km from the Andean volcanic arc. Although previous works mention the presence of pumice in this unit, an analysis of the origin, the transport and depositional processes of these fragments was not carried out. Based on the study of stratigraphic sections along the extra-Andean zone, it was determined that the sediments of the Lower Miocene (Chichinales Formation) were deposited in a low-to-medium energy fluvial environment with development of wide floodplains and palaeosol formation during stability periods. The Middle Miocene?—Lower Pliocene deposits (El Palo Formation) correspond to a moderate-to-high energy braided fluvial system with occasional high discharge periods. The pumice fragments present in this unit were derived from the reworking of primary pyroclastic deposits outcropping at the foot of the Andes, associated with important explosive volcanic activity during the Miocene. These fragments were transported and deposited by both dilute flows and sediment gravity flows with high concentrations of pumice. Petrographic analysis of El Palo Formation sandstones showed a provenance mostly related to the erosion of pyroclastic, arc-related deposits. The main source areas would have been the Andean arc and the North Patagonian Massif. A maximum depositional age of 14.6 ± 1 Ma was obtained in a sample from the El Palo Formation, which constitutes the first U–Pb dating of detrital zircons from this unit in the study area. This age matches with a peak of magmatic activity of the Patagonian Batholith responsible for huge arc-derived ignimbrites recorded at the foot of the Andes.

Jurassic and Early Cretaceous times were marked by significant changes in Earth's climate and tectonics, most notably the breakup of the supercontinent Pangaea, which led to the opening of the Atlantic Ocean. In Southwest Britain, one of the most prominent features of this time is the Base Cretaceous unconformity representing widespread erosion and non-deposition separating Cretaceous strata from underlying rocks. Despite its widespread presence in Southwest Britain, Iberia, Ireland and conjugate North Atlantic basins, the origin and nature of this unconformity remains enigmatic. To better understand its nature, seismic data was used to map the extent of the unconformities and to establish their relationships with onlapping Jurassic and Cretaceous stratigraphy. We reveal that the Base Cretaceous unconformity is a composite of at least three—Middle Jurassic, Late Jurassic to Early Cretaceous and Mid-Cretaceous—unconformities likely generated by erosion and non-deposition. The Mid-Cretaceous unconformity is often assumed to be responsible for the majority of erosion, but our findings suggest otherwise. Onlap patterns of the Lower Cretaceous Wealden Formation on truncated Jurassic units indicate that the Jurassic to Early Cretaceous unconformity was the most significant. Amplitudes of uplift across different basins in SW Britain are shown to be variable. The most substantial denudation occurred following Berriasian uplift, likely linked to shortening associated with North Atlantic opening. The Mid-Cretaceous unconformity is more subtle, primarily observed at basin margins and linked to the rift-drift transition of the Bay of Biscay. Subsidence histories differ across basins; some (e.g., Brittany Basin) can be explained by simple post-rift thermal cooling models, while others (e.g., Melville and South Celtic Sea Basins) require more complex explanations due to substantial missing stratigraphy, including reactivation of Variscan thrusts and sub-plate support. Our results emphasise that spatially and temporally distinct tectonic and denudation events can combine to generate large-scale composite unconformities.

This study presents a detailed 3D lithofacies model of the Upper Pleistocene–Holocene Tiber Depositional Sequence (TDS) within the alluvial plain of Rome, Italy, developed using an integrated approach. A deterministic framework was used to establish 1D lithofacies constraints, while geostatistical algorithms, particularly indicator kriging, were employed to reconstruct the stacking patterns and interfingering of lithofacies within systems tracts. This methodology allows for the realistic depiction of depositional trends and stratigraphic architecture while addressing challenges posed by limited data density in unsampled locations. The resulting 3D model demonstrates its ability to honour observed data while enabling meaningful extrapolation of subsurface features. The model captures key evolutionary trends and aligns with the conceptual 2D stratigraphic reconstruction developed in this study and the sequence-stratigraphic framework of the TDS derived from previous studies. Stratigraphic cross-sections and 2D correlation profiles extracted from the 3D model reveal the depositional architecture and constrain the thickness and extent of primary lithofacies associations. Key findings include the identification of braided and meandering channel-belt complexes associated with poorly and well-drained floodplain deposits. The lowstand systems tract (LST) is characterised by extensive braided channel belts with high width-to-thickness ratios, while the transgressive systems tract (TST) exhibits vertically stacked meandering channels associated with poorly drained floodplains. The highstand systems tract (HST) shows increased channel clustering and lateral expansion of meandering channel belts, associated with well-drained floodplain deposits displaying pedogenic features. The findings highlight the strengths and limitations of two-point geostatistical algorithms, with indicator kriging outperforming traditional methods like Truncated Gaussian Simulation and Sequential Indicator Simulation in maintaining geological coherence and lateral continuity. The 3D model enhances our understanding of the Tiber alluvial basin evolution and provides a robust framework for urban geological applications. It serves as a pivotal tool for managing subsoil resources, mitigating geohazards, and preserving cultural heritage in densely populated areas. This approach demonstrates the feasibility of applying efficient, scalable techniques to model sedimentary successions in similar urbanised alluvial settings worldwide.