Basin Research最新文献

Stratigraphy and its associated grain size preserve a record of the dynamic behaviour of source-to-sink systems over time. Sediment supply and available accommodation space primarily control downstream grain-size fining preserved in stratigraphy. In principle, these grain-size trends can be inverted to quantify temporal and spatial variation in these driving forces. Here, we illustrate how grain size and stratigraphic thickness can be used to quantify fault growth and interaction using the early-mid Pleistocene Pirgaki-Mermoussia (P-M) fault, Gulf of Corinth, Greece, as a natural laboratory. A 2.5 km long exposed cliff section of the uplifted Kerinitis Gilbert-type delta, which lies in the hanging wall of the P-M fault, was selected for study. In the field, we traced out stratigraphic units in the lower part of the Kerintis delta, which are bounded by flooding surfaces, and measured their thickness to reconstruct hanging wall subsidence. We collected down-system grain-size data at 31 measurement sites using the Wolman point count method. Our results show the observed grain-size fining rate increase from 11 to 17 mm.km⁻¹ for the lower delta deposits over a timescale of up to 120 kyr. Using a self-similarity-based grain-size fining model and considering a minimum increase in accommodation generation from 0.6 to 1 mm year⁻¹ over this period, we reconstruct an increase in delta sediment supply from ca. 170 to 460 m³ year⁻¹. The integration of stratigraphic thickness measurements with grain-size fining trends enables quantitative reconstruction of temporal variations in fault-driven accommodation space and sediment supply, thereby demonstrating fault slip rate evolution. We show an increase in the P-M fault slip rate during its early history from 1 to 2 mm year⁻¹, reflecting early interaction of the P-M fault segments over ca. 120 kyr. Reconstructed catchment-averaged erosion rates are ca. 20% of the footwall uplift, implying a transient response of the landscape to the P-M fault growth. These analyses demonstrate how grain-size data from a well-constrained geological example can be used to reconstruct landscape dynamics quantitatively in fault-controlled sedimentary systems with high temporal and spatial resolution.

The Levant Basin of the Eastern Mediterranean accumulated voluminous siliciclastic sediments during the Oligocene–Miocene. The deep-sea section has attracted significant interest as it contains world-class hydrocarbon reservoirs (‘Tamar Sands Play’). Our recent sandstone provenance study revealed that the hydrocarbon-bearing, lower Miocene ‘Tamar Sands’ were recycled from older quartz-rich sandstones that covered the Arabian flank of the Red Sea Rift. However, sandstones constitute just a third of the thickness of the Oligocene–Miocene siliciclastic section in the Levant Basin, with the rest being mainly composed of shales. Unravelling the provenance of the shale fraction is therefore essential for a comprehensive reconstruction of the Oligocene–Miocene source-to-sink system of the Levant Basin. In the present study, we examined the mineralogy and Sr-Nd isotopes of clay samples retrieved from deep-sea boreholes that penetrated the Oligocene–Miocene siliciclastic section. The isotopic composition of most clay fractions resembles that of Nile Delta sediments, indicating that unlike the ‘Tamar Sands’, their dominant provenance lay in NE Africa. Our investigations show that they were derived from Neoproterozoic basement rocks of the Arabian-Nubian Shield and Tertiary continental flood basalts. The absence of chlorite and serpentine negates detrital contribution from the Arabia-Eurasia suture in the north. Compilation of the available thermochronology data and major geologic events shows that the accumulation of the siliciclastic section in the Levant Basin coalesced with uplift of the continental areas around the Red Sea. The marked switch to shale deposition recognised in the basin during the late early Miocene signifies the downfall of the ‘quartzose’ Arabian sediment transport system, when it was partially captured by the evolving Dead Sea Transform valley. Our study highlights the strength of coupling sand and clay provenance investigations in source-to-sink studies of sedimentary basins.

In this contribution, we document changes in detrital zircon ages in the upper Devonian (Famennian) to lower Carboniferous (Mississippian) Billefjorden Group on Bjørnøya, the southernmost island of Svalbard. This alluvial, coal-bearing clastic succession is widely distributed across the archipelago and the Barents Shelf. The sediments were deposited in subsidence-induced lowlands that formed just after regional post-Caledonian collapse-related extension, which created the classical ‘Old Red Sandstone’ basins during the Devonian, and prior to localised rift-basin development in the middle Carboniferous (Serpukhovian–Moscovian). Moreover, the succession is little affected by Ellesmerian compressional deformation, which occurred in the latest Devonian. However, little is known of the provenance and regional sediment routing in this tectonically transitional period between the post-Caledonian structuring events in the Devonian and the middle Carboniferous rifting. It has previously been invoked that a regional fault running parallel to the western Barents Shelf margin, the West Bjørnøya Fault, controlled sedimentation in the area. Here, we combine detrital zircon U–Pb ages and sedimentological data to investigate stratigraphic provenance variations and test whether tectonics controlled deposition of the Billefjorden Group on Bjørnøya. Sedimentological investigations demonstrate changes in fluvial style with intercalations between successions dominated by meandering channel fills and abundant overbank fines to sandstone-dominated sheet-like successions of braided stream origin. Palaeocurrent data show that two competing drainage directions accompany the changes in fluvial architecture. Northeasterly transport directions, recorded in the braided stream deposits, indicate possible fault-transverse drainage. The detrital zircon content in these deposits indicates sourcing from Caledonian terranes in Northeast Greenland. Northwest-oriented transport directions, measured in the meandering channel deposits, are inferred to represent axially positioned drainage systems. These may have been sourced from either Northeast Greenland, a more localised source, or Baltica. The latter would require long-distance sourcing, which, given the tectonic setting of the region, seems unlikely. Although our sedimentological observations point to syn-tectonic deposition, this is not clearly captured in the detrital zircon data, suggesting a common source for the Late Devonian–Mississippian fluvial systems of Bjørnøya. Thus, combined with previously published provenance data from Svalbard and Greenland, we demonstrate that the East Greenland Caledonides formed a long-lived and significant source area which provided sediments to nearby basins from the Devonian to the Early Cretaceous.

The exhumed hydrocarbon traps of East Greenland provide a superb opportunity to study the evolution of fluid flow in the petroleum systems of the North Atlantic. Following basin inversion during the Cenozoic these structures were exhumed and deeply incised which has allowed them to be observed and mapped in great detail. This study examines the diagenetic history of the Mols Bjerge and Laplace Bjerg exhumed hydrocarbon traps, from the initial charge of Triassic and Jurassic reservoirs, to their eventual uplift and destruction. Detailed petrographic analysis was undertaken on 67 samples collected at representative intervals throughout the structures. Variations in the distribution of diagenetic phases and remnant porosity were investigated. Twenty three samples were also subjected to helium porosity measurement. Bitumen, up to 18%, was recognised in 34 samples, 6 of which were analysed for their form and reflectance. Fluid inclusion data, collected from the nearby Bjørnedal region, helps to constrain the thermal history of the region. Helium porosity and permeability measurements are low, largely below 10% and 2 mD respectively. However, the abundance of bitumen highlights the presence of significantly higher porosity and permeability during hydrocarbon charge. A synthesis of fluid inclusion data and bitumen reflectance, alongside a detailed examination of the paragenetic sequence, demonstrate that hydrocarbon charge occurred in the Eocene, during maximum burial, at which time only a minor reduction in original intergranular porosities had taken place. The destruction of the pore systems occurred due to the degradation of hydrocarbons to bitumen, resulting from heat flow during intrusive events, and subsequent carbonate and limonite cementation during uplift. The original source of the hydrocarbons is unclear. This work highlights that where unaffected by intrusives and uplift, the largely untested Triassic play may still contain viable reservoir intervals at depth on the Norwegian Continental Shelf.

Paleo source to sink system analysis requires a complete earth systems model approach, utilising regional geology, tectonics, climate and modern-day source to sink analogues. This study examines the Cretaceous source to sink systems of Senegal, NW Africa, integrating a broad regional dataset using a multidisciplinary mineralogical approach. The most significant regional geological and tectonic events to affect Senegal since the Pan-African Orogenies (800–520 Ma) are the Hercynian Orogeny (320–290 Ma), Pangea break-up and rifting between S. America and Africa, with associated Central Atlantic Magmatic Province volcanism (200 Ma) and uplift of the Mauritanide hinterland (113–66 Ma). In addition to tectonic controls, climate is the principal driver for paleo-drainage reorganisation. During the Cretaceous an antithetical shift in climate from warm and arid (145–115 Ma), to hot and humid (100–88 Ma), increased fluvial catchment and energy. Antecedent paleo-drainage of the Cretaceous Senegalese Basin is governed by subsurface grabens striking hundreds of kilometres into the continent formed during Atlantic rifting. Early Cretaceous aridity restricted fluvial catchments to recycling pre-Cretaceous basinal sediments. Climate change triggered expansion of paleo-drainage catchments during the Aptian caused fluvial incision and erosion of the Gaouâ Group Hercynian to Pan-African age source rocks along the western flank of the Mauritanides. Exhumation increased significantly throughout the Cretaceous Thermal Maximum during the Cenomanian–Turonian, with exhumation of the Gadel Group Pan-African source rocks, evidenced from a shift between a garnetiferous to staurolitic basin mineralogy. Inclusion of 200 Ma zircons into the central Senegalese Basin during the Albian is evidence of possible catchment shifts to include CAMP detritus from the Fouta Djallon Plateau. Cretaceous basinal sediments are almost exclusively sourced from the Mauritanide belt which includes Hercynian metamorphic host rocks and Palaeozoic sediments ultimately derived from the erosion of the Pan-African orogenic belts. During the Maastrichtian, the central fluvial systems breached the southern Mauritanides, sourcing Cambrian zircons from the south.

The submarine Miocene Central Canyon and Pleistocene channel systems in the Qiongdongnan Basin constitute valuable sedimentary records that provide insight into the depositional processes and sediment routing from the hinterland to the deep sea. However, the primary source of sediment for the Pleistocene channel systems and the variation in relative sediment contributions since the Miocene from potential source terranes remain unknown. We have integrated new and published detrital zircon U–Pb ages and rare earth elements (REEs) from Pleistocene channel sands and late Miocene Central Canyon sands in the Qiongdongnan Basin to analyse the sediment routing system of these channel systems since the Miocene. Qualitative analyses of REEs, comparisons of detrital zircon age spectra, and multidimensional scaling plots suggest that the Red River is a significant source of sediment supply. The quantitative analysis of sediment mixing models indicates that the Pleistocene channel sands were mainly sourced from the Red River (62.8%–85.7%), followed by Central Vietnam rivers (4.8%–27.1%), with a minor amount derived from rivers in Hainan Island, Northern Vietnam and Southern Vietnam. Sand sediments, mainly from the Red River system, were deposited in the Yinggehai Basin, then transported and deposited again in the Qiongdongnan Basin. The relatively stable and major sediment supply from the Red River since the Miocene may have been driven by the uplift of the Tibetan Plateau. This study quantifies the relative provenance contributions to submarine channel systems in the Qiongdongnan Basin since the Miocene. It provides crucial geological implications for tectonic responses to channel migrations and the prediction of gas hydrates in sandy reservoirs.

Exhumation affects sedimentary basin evolution by influencing structural, pressure and temperature dynamics, thereby impacting energy resource formation. Compaction-based methods are widely used to quantify exhumation, utilising sonic and porosity data to track sediment uplift from its maximum burial depths. However, uncertainties arise from applying empirical compaction models developed for specific geological regions, highlighting the need for region-specific models. Even such region-specific models contain uncertainties, which can compromise exhumation estimates. We, therefore, develop a probabilistic compaction model for the Northwest Shelf Basins using sonic data from normally compacted and unexhumed shales from the Northern Carnarvon Basin (NCB). The model's robustness is estimated using MCMC, and uncertainty propagation analysis is employed to assess the impact of model uncertainty on the model's predictive applications. The model shows exponential porosity reduction with depth, demonstrating rapid compaction from the surface to ca. 2 km and slower compaction thereafter. The model is then applied to interpret new datasets from the Canning, Gippsland and NCB regions. The results reveal that while some parts of the NCB exhibit normal compaction without exhumation, others were significantly exhumed. Conversely, Canning and Gippsland Basin data indicate signs of significant exhumation, as suggested by previous studies, thereby confirming the model's effectiveness outside the Northwest Shelf. Since the model could not explain data from exhumed regions, we inferred new models incorporating “exhumation” parameters to interpret the complex compaction histories of these areas, and the best-fitting models were selected using the Bayes Factor method. Uncertainty analysis revealed that the impacts of model uncertainty on exhumation estimates are consistent across wide depth ranges. Our findings highlight the need to refine compaction models for better predictive reliability and informed resource exploration in sedimentary basins.

Detachment fault system associated with a mature metamorphic core complex (MCC) is still not well understood. Using high-resolution 3D seismic data, we analyse the geometries and kinematic development of detachment fault system associated with a mature and exhumated MCC in the northern South China Sea rifted margin, with an emphasis on the MCC-associated faults within the supra-detachment basin. Faults within the supra-detachment basin can be classified into three stages, the pre-MCC, syn-MCC and post-MCC faults, based on their formation time relative to the MCC. The NE to NEE-striking pre-MCC faults developed in the early syn-rift 1 stage, and the NW to WNW-striking post-MCC faults were both dominated by the regional tectonics and are perpendicular to the extension directions. While the syn-MCC faults, synchronous with the MCC development in the late syn-rift 1 stage, show overall EW-striking, consistent with the long axis of the KP MCC. These syn-MCC faults were well developed and are significant in shaping the basin architecture. Besides, the syn-MCC faults are regularly distributed in the four zones overlying the convex-upward master detachment fault surface, and are defined in this study as a synthetic fault zone, an upper collapse synformal-graben fault zone, a lower collapse antiformal-graben fault zone and an antithetic fault zone respectively. These four fault zones show distinct features and evolutionary patterns, and have a closed relationship with the rolling-hinge process of the KP MCC. An evolutionary model is established for the development of MCC-associated detachment fault system which should have global implications.

The Cenozoic topographic growth of the Tibetan Plateau is a pulsed, polyphase process that still requires more constraints. The Cenozoic sedimentary record of the Ningnan Basin, a continental basin located adjacent to the northeastern margin of the Tibetan Plateau, is a key archive for recording the surface evolution of the Tibetan Plateau. This work reports new provenance data (apatite fission-track, apatite U–Pb dating, and trace element analysis on the same individual grains) from the Oligocene–Pliocene sedimentary sequence that filled the Ningnan Basin. The data set shows variations in provenance patterns through the Miocene which are related to the tectonic evolution of the northeastern margin of the Tibetan Plateau. In contrast to a primary provenance from the Western Ordos Block (WOB) during the Oligocene, the Miocene sediments were mostly derived from the recycling of Mesozoic successions that occur along the northwestern Haiyuan Fault, documenting it was active in the last ca. 15 Myr. These sediments, in turn, were derived from different orogenic blocks but mainly from different segments of the Qilian Mountains. We show that the Late Miocene–Pliocene sediments were primarily derived from transpressional uplift along the Haiyuan Fault, which affected regions such as the Liupan Mountains. Progressive northeastward migration of tectonic stress since the Middle Miocene has induced extensive regional deformation in the northeastern Tibetan Plateau, particularly along the Haiyuan Fault. The provenance record of the neighbouring Cenozoic basins is a key archive for deciphering this tectonic evolution.