Basin Research最新文献

{"title":"Geometric and Spatial Analysis of Wing-Like Intrusions as Outcrop Analogues for Subsurface Analysis","authors":"Robert J. Waltham,&nbsp;Gustavo Zvirtes,&nbsp;Brian S. Burnham,&nbsp;Andrew Hurst","doi":"10.1111/bre.70036","DOIUrl":"https://doi.org/10.1111/bre.70036","url":null,"abstract":"<p>Wing-like intrusions are some of the most prominent architectural elements identified within subsurface sand injectite complexes. These structures are composed of discordant inner wing zones and bedding-concordant outer wing zones, which can crosscut hundreds of metres of stratigraphy and extend laterally for several kilometres. Their large-scale geometry makes them discernible on seismic data; however, the inability to detect associated smaller intrusions can lead to underestimates of their significance within a basin. To support subsurface analysis, this study integrates field and digital mapping analyses of two wing complex outcrops from two giant injection complexes of the San Joaquin Basin. The Dosados Canyon wing, of the Panoche Giant Injection Complex (PGIC), features a single 14 m thick stepped inner intrusion that bifurcates into outer sills. The wing extends laterally over 1.5 km, crosscutting ca. 300 m of mudstones. Up to 64% of the sandstones are associated with sub-seismic intrusions (&lt; 3 m thickness). The Tumey Hill wing within the Tumey Giant Injection Complex (TGIC) intrudes vertically &gt; 200 m of mudstones and extends laterally for at least 1.3 km. It comprises laterally stacked inner intrusions (up to 12 m thick) transitioning to a highly connected outer sill zone. A total of 225 intrusions (0.15 m to 8 m thick) are identified within the composite wing structure, adding sand volume and providing excellent connectivity. Comparison with the Volund and Varadero fields within the North Sea reveals intrusions with similar scale and geometry, underscoring the value of the outcrops as analogues for characterisation of subsurface reservoirs and to aid the understanding of sand intrusion formation within different basin settings.</p>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imaging Bajocian Coral Ridges in the Paris Basin and Deciphering Their Origin","authors":"Benjamin Brigaud,&nbsp;Benoît Vincent,&nbsp;Marc Pessel,&nbsp;Albane Saintenoy,&nbsp;Hermann Zeyen,&nbsp;Christophe Durlet,&nbsp;Jessica Saïag,&nbsp;Michel Hayet","doi":"10.1111/bre.70034","DOIUrl":"10.1111/bre.70034","url":null,"abstract":"&lt;p&gt;Enigmatic N120° ridges have been identified from 3D seismic reflection imaging of the Bajocian limestones of the eastern Paris Basin. These features may impact flows within the active Middle Jurassic aquifer beneath the Callovian–Oxfordian claystones and marls that host the Underground Research Laboratory (URL) where the Andra (French National Agency for Radioactive Waste Management) is studying the feasibility of a deep repository for radioactive waste. Worldwide, there are numerous other examples where carbonate buildups form ridges in 3D, which are more or less interconnected, laterally amalgamated, or bifurcating, with no clear reason for these geometric features. It is consequently of paramount importance to understand the nature and origin of these ridges, and an integrated study combining (1) well logs, (2) new 3D seismic acquisitions, (3) classical field sedimentology and stratigraphy, (4) near-surface geophysics including ground penetrating radar (GPR), electrical resistivity tomography (ERT) and frequency-domain electromagnetics (FDEM) and (5) seismic refraction has been developed to investigate them. Facies analysis and a regional sequence stratigraphy interpretation, integrating near-surface geophysical imaging performed on time-equivalent outcrop sections, demonstrate that elongated mounds of hermatypic scleractinian corals developed during the early Bajocian (&lt;i&gt;Humphriesianum&lt;/i&gt; chronozone) in shallow, warm oligotrophic seawater. These buildups nucleated as patches on hardground atop giant subaqueous dunes composed of peloidal and bioclastic grainstones, dipping mostly N30° with N120°-oriented crests. Some of the coral reefs form buildups up to 15 m high and several hundred meters wide. They are elongated in the main N120° direction of the underlying dunes, although the dispersion of measurements illustrates the complexity of the interfingered structures observed in 3D seismic images. The coral buildups are progressively onlapped and draped by oncoid-rich alternating marl-limestones that may result from a shift from oligotrophic to mesotrophic conditions probably brought about by a rise in relative sea level. Near-surface geophysics provide insightful supporting evidence to supplement the field work, particularly by imaging the roots of several coral reefs, their internal structures and the infill of the inter-reefal troughs. This work demonstrates the critical importance of outcrop analogue studies for resolving subsurface problems and also shows how near-surface geophysical methods can usefully supplement direct classical field geology investigations. This new characterisation suggests that coral reefs forming ridges, structures that have often remained enigmatic, could develop by directly settling at the top of early cemented giant oo-bioclastic dunes. Submarine early diagenesis generates hardgrounds that constitute stable substrates for nucleation and growth of coral reefs, especially when they cap prominent submarine relie","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal Melting Events During the Late Stage of Syn-Rift at the Magma-Intermediate Continental Margin: A Numerical Study From the Northern South China Sea Margin","authors":"Fucheng Li,&nbsp;Zhen Sun,&nbsp;Hongfeng Yang,&nbsp;Yunying Zhang,&nbsp;Ziying Xu,&nbsp;Lijie Wang","doi":"10.1111/bre.70035","DOIUrl":"10.1111/bre.70035","url":null,"abstract":"<div>\u0000 \u0000 <p>The traditional distinction of magma-poor and magma-rich margins is challenged by the presence of significant late-stage rift-related magmatism in certain margins, such as the South China Sea (SCS). We use numerical modelling to investigate the conditions and processes that lead to crustal melting and the formation of high-velocity lower crustal layers (HVLs) in such magma-intermediate margins. The models demonstrate that the preferential removal of the lithospheric mantle during rifting is crucial for crustal melting, as it allows the crust to receive sufficient heat from the upwelling asthenosphere. The extent and distribution of crustal melts are influenced by extension velocity and crustal rheology, and the models reveal a strong correlation between the presence of crustal melts and thin-crust domains (&lt; 20 km thick). The study reveals a younger-oceanward trend in magmatism, attributed to the progressive exposure of the crust to the hot asthenosphere during rifting. Comparison of modelling results with seismic observations from the SCS margin suggests that both asthenospheric and crustal melts contribute to the formation of HVLs, with crustal melts estimated to constitute approximately 15%–30%. The results not only deepen our understanding of magmatic processes in magma-intermediate margins, but also provide quantitative evidence for the classification and interpretation of passive margins.</p>\u0000 </div>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143926914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Misleading Basin Margins—Analysis of the Upper Permian Succession in the Retroarc Foreland Bowen Basin of Northeast Australia","authors":"Jasmin Naher,&nbsp;Christopher R. Fielding,&nbsp;Mike A. Martin","doi":"10.1111/bre.70033","DOIUrl":"10.1111/bre.70033","url":null,"abstract":"<div>\u0000 \u0000 <p>The meridional, Permo–Triassic Bowen Basin of NE Australia became a retroarc foreland basin in the late Permian, with a mapped foredeep axis (Taroom Trough) running north–south adjacent to the eastern edge of the basin. The present outline of the basin is, nonetheless, shaped by significant structural deformation along its eastern margin, and stratigraphic pinch-outs and erosional truncation in the west. The plan form of the basin thus gives a potentially misleading representation of the basin's original shape and extent. By analysing wireline log data from over 1000 drillholes, we developed isochore, net sand thickness, and net-to-gross maps, which inform a new set of palaeogeographical maps for the three upper Permian formations of the Bowen Basin (Peawaddy Formation, Black Alley Shale, and Bandanna Formation, in ascending order). These maps were further refined using palaeocurrent data from outcrops and validated against logged vertical sections from various parts of the basin. Isochore plots for the three formations indicate abrupt truncation of contour lines along the structural eastern margin, in the Taroom Trough. This pattern is interpreted as evidence of significant erosion of stratigraphy along the eastern basin margin during contractional deformation. Based on these findings, we posit that the Taroom Trough synclinal axis does not represent the original foredeep axis, which we propose was located farther east and was erosionally excised. The configurations of sand-prone depositional systems, and the preservation of upper Permian strata outside the structural basin boundaries, support the hypothesis that the original eastern depositional edge of the basin extended farther east than its current structural boundary. Similarly, truncation and westward onlap of formations along the western margin suggest that the basin's original western boundary lay beyond its present margin. Based on the truncated isochores and other criteria, we estimate that the preserved part of the basin is ~50% of its original area.</p>\u0000 </div>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143915598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal Segmentation Between Failed Rift and Successful Rifted Margin Along the NW South China Sea","authors":"Shihao Hao,&nbsp;Lianfu Mei,&nbsp;Guangrong Peng,&nbsp;Lili Zhang,&nbsp;Jing Wu,&nbsp;César R. Ranero","doi":"10.1111/bre.70029","DOIUrl":"10.1111/bre.70029","url":null,"abstract":"<div>\u0000 \u0000 <p>Most works propose a genetic “wide-rift” model for the northern South China Sea (SCS) rifted margin, where low-angle detachment faults accommodate significant deformation during crustal extension. However, a new seismic grid along the northern SCS shows along-strike changes in tectonics. At least two distinct tectonic domains, i.e., “wide-rift” Eastern Domain and “narrow-rift” Western Domain, have been revealed, which indicates that the current conceptual SCS rift models are likely too simplistic. Whereas, the Western Domain remains little explored because of the lack of available 3D seismic data and boreholes here. The 3D rift architecture in this tectonic domain is therefore inadequately constrained, which leads to insufficient knowledge of the syn-tectonic rift evolution in this region. Based on an unpublished 2D deep-penetration grid of seismic reflection sections, we have investigated the faulting style, sedimentary structure, and crustal architecture in the Western Domain of the mid-northern SCS. Our data display that the Western Domain contains the Changchang and Heshan Segments separated by a transfer fault zone. The aborted Changchang Segment is characterised by landward-dipping faults and younger T60 breakup unconformity. The neighbouring Heshan Segment, reaching the final continental breakup, is characterised by oceanward-dipping faults and older T70 breakup unconformity. The observations imply abrupt along-strike rifting changes not contemplated by current models, requiring unexplained crustal or mantle heterogeneity during extension.</p>\u0000 </div>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Geomorphology of an Early Eocene Canyon-Channel-Lobe System North of Shetlands","authors":"Hans Jørgen Kjøll,&nbsp;Ivar Midtkandal,&nbsp;Ben Manton,&nbsp;Sverre Planke","doi":"10.1111/bre.70031","DOIUrl":"https://doi.org/10.1111/bre.70031","url":null,"abstract":"<p>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.</p>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the Stratigraphy and Structure of the Faroe Islands Flood Basalts for Large-Scale CO2 Storage in Basalt Reservoirs","authors":"Rakul Maria Ingunardóttir Johannesen,&nbsp;Jana Ólavsdóttir,&nbsp;Lars Ole Boldreel,&nbsp;Óluva Eidesgaard,&nbsp;Kim Senger,&nbsp;Olivier Galland","doi":"10.1111/bre.70032","DOIUrl":"https://doi.org/10.1111/bre.70032","url":null,"abstract":"<p>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.</p>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transport and Depositional Processes of Neogene Pumice Fragments in a Distal Fluvial System of the Northern Patagonian Foreland (Argentina)","authors":"Lucas Peñacorada,&nbsp;Ricardo Gómez,&nbsp;Maisa Tunik,&nbsp;Silvio Casadio","doi":"10.1111/bre.70028","DOIUrl":"https://doi.org/10.1111/bre.70028","url":null,"abstract":"<p>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.</p>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two Stages of Rifting Control the Crust Thinning and Basin Evolution: Insights From the Southern Qiongdongnan Basin, NW South China Sea","authors":"Jingyuan Yu,&nbsp;Dianjun Tong,&nbsp;Chen Hu,&nbsp;Yancheng Xu,&nbsp;Jianye Ren","doi":"10.1111/bre.70030","DOIUrl":"https://doi.org/10.1111/bre.70030","url":null,"abstract":"<div>\u0000 \u0000 <p>In rifted margins or rifted basins, the structure of the basin is often complex due to the multistage development of fault systems. As we can only see the result of the basin evolution, it is difficult to judge the influence of early fault activity on the later stages. Here, we present a case study from the southern part of Qiongdongnan Basin (QDNB) where the influence of the early stage can be clearly recognised. Using newly acquired high-resolution 3D seismic datasets, we analyse the prototype and temporal evolution of the study area since the Cenozoic. Three fault systems (FS1, FS2 and FS3) were identified according to fault activities and fault strike. Observation results show a rotation of the stress field at the end of the Eocene, dividing the whole rifting into two stages. FS1 initiated in NW-SE extension at rift stage I (42.5–33.9 Ma), showing a typical basement-involved structure while FS2 and FS3 developed in N-S extension at rift stage II (33.9–23.03 Ma). The faults in FS1 were either crosscut to form a zigzag plane geometry by FS2 and FS3 faults, or became long-lived active faults throughout the rifting period, resulting in a localisation of strain and extremely thinning of the crust. It can also be compared with adjacent basins which have undergone the same regional tectonic evolution history at the northern margin of the South China Sea. The long-lived NE–SW trending faults cause significant variation in the subsidence history, basin structure, and crust thickness along strike in the study area, indicating that faults developed in rift stage I play a significant role in basin evolution at rift stage II.</p>\u0000 </div>","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 3","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation and Architecture of Subsurface Strata in the Whatcom Sub-Basin, Georgia Basin, Canada and USA","authors":"Maziyar Nazemi,&nbsp;Shahin E. Dashtgard,&nbsp;Chuqiao Huang,&nbsp;Md Jamilur Rahman,&nbsp;James A. MacEachern,&nbsp;Francyne Bochi do Amarante","doi":"10.1111/bre.70027","DOIUrl":"https://doi.org/10.1111/bre.70027","url":null,"abstract":"&lt;p&gt;Outcrops of sedimentary strata that infill the Georgia Basin, Canada and USA have been studied extensively as they record information on the tectonic evolution of western North America. However, these outcrops are situated in only a limited extent of the basin (mainly Vancouver Island) and preserve mainly Upper Cretaceous strata, and so the information that can be derived from outcrops is incomplete and spans less than half of the Georgia Basin's temporal history. The majority of the Georgia Basin, and the complete stratigraphy, occurs in the subsurface in the Whatcom Sub-Basin, which extends below much of the Strait of Georgia, the Lower Mainland of British Columbia (LMBC), Canada and northwest Washington, USA. In this study, we reconstruct the stratigraphic architecture, evolution and palaeogeography of Upper Cretaceous and Cenozoic strata in the Whatcom Sub-Basin, and we use these data to develop a more complete record of the depositional history of the Georgia Basin and its evolution relative to major tectonic events along North America's west coast. We focus on the Canadian extent of the Whatcom Sub-Basin, the LMBC, because of the availability of two-dimensional seismic reflection datasets and cored intervals, which enable facies characterisation and provide detrital zircon datasets. The stratigraphy of the Whatcom Sub-Basin is divided into four stratal packages, including: lower Nanaimo Group, upper Nanaimo Group, Huntingdon Formation and Boundary Bay Formation. The few outcrops and a single cored interval suggest that the lower Nanaimo Group is dominated by fluvial strata in the Whatcom Sub-Basin. The upper Nanaimo Group is dominated by fluvial strata in the central part of the Whatcom Sub-Basin and turbidites and deep-marine strata in the west, and this facies relationship indicates that sediment transport was to the west. The Eocene and younger Huntingdon and Boundary Bay formations record re-organisation of the basin, with a shift in sediment transport to the south and southwest. Both the Huntingdon and Boundary Bay formations are dominated by terrestrial strata with evidence of marine influence increasing towards the southwest but decreasing stratigraphically upwards. Changing sediment transport pathways and recycling of Nanaimo Group strata in Eocene time reflect the bifurcation of the Georgia Basin with uplift of the forearc high (i.e., Vancouver Island). Boundary Bay Formation deposits extend further east than do all other stratigraphic units, and detrital zircon-based maximum depositional age estimates indicate that parts of the Lower Mainland probably have experienced active subsidence for at least the past 15 million years. A comparison of our data to tectonic events along North America's western margin indicates that (a) the fill and geometry of the basin evolved due to syn- and post-depositional tectonism, and (b) basin topography and syntectonic activity drove major changes in depositional environments both areally and temp","PeriodicalId":8712,"journal":{"name":"Basin Research","volume":"37 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bre.70027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}