Depositional Record最新文献

{"title":"Testing geological proxies for deep‐time tidal model simulations","authors":"B. Guo, L. A. M. Fitzgerald, J. M. Hewitt, O. Pampaloni, J. A. M. Green","doi":"10.1002/dep2.256","DOIUrl":"https://doi.org/10.1002/dep2.256","url":null,"abstract":"Abstract Tides are a key driver of a range of Earth system processes, and we now have the capacity to simulate tidal dynamics on a range of temporal and spatial scales. Deep‐time tidal model simulations have been used to provide insight into past ocean circulation patterns, evolution of life and the developments of the Earth‐Moon system's orbital configuration. However, these tidal model simulations are relatively poorly constrained and validated because of a lack of readily available proxies. The feasibility of using two types of proxy is explored here; (1) sedimentary deposits which can directly estimate palaeotidal ranges, and (2) black shale, to constrain three palaeotidal model simulations for different time slices. Specifically, three palaeotidal range proxies were used for the early Devonian (400 Ma), three palaeotidal range proxies and five black shales for the lower Jurassic (185 Ma), and eight black shales for the early Cretaceous (95 Ma). Both tidal proxies confirm the tidal model results in most locations. The model results for 400 Ma and 185 Ma matched 2/3 of the palaeotidal range proxies for each of these periods. The locations of black shale were compared with tidal front locations predicted by the model outputs based on the Simpson–Hunter parameter and the model results from 95 to 185 Ma agree with the black shale proxies in 10/13 of the locations. In the cases where there is a disagreement, the model resolution is probably too low to fully resolve the details of the coastal topography, or—in one case—the palaeobathymetry is incorrect. Consequently, it is argued that it is worth expanding this type of work, and that such data can be used to validate both models and reconstructions.","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135889007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The origin of planar lamination in fine‐grained sediment deposited by subaqueous sediment gravity flows","authors":"Omar N. Al‐Mufti, R. William C. Arnott","doi":"10.1002/dep2.257","DOIUrl":"https://doi.org/10.1002/dep2.257","url":null,"abstract":"Abstract Planar lamination is a ubiquitous component of modern and ancient fine‐grained sediments deposited by subaqueous sediment gravity flows. These sediments commonly exhibit alternating sub‐millimetre‐thick, sharply bounded silt‐rich and clay‐rich layers that change little in thickness or sediment texture over lateral distances that range up to at least several tens of metres. Silt‐rich layers are moderately to well‐sorted and a few tens to hundreds of microns to a single silt‐grain thick. In contrast, clay‐rich layers are more poorly sorted, and a few tens to hundreds of microns thick. The thickness and regular alternation of these texturally differentiated interlayers, in addition to the absence of features suggesting transport bypass or deposition by migrating rugged bed forms, suggest alternating physical processes and related modes of deposition in the near‐bed region immediately above the bed. Previous interpretations have focussed on clay flocculation, which is difficult to reconcile with the high fluid shear conditions in the near‐bed region. Here it is suggested that in the millimetre to sub‐millimetre‐thick viscous sublayer at the base of a hydraulically smooth turbulent flow, a combination of high fluid shear and sediment concentration initially leads to shear thinning and enhanced mobility in the lower part of the flow, and for silt to continue settling to the bed forming a well‐sorted silt lamina. As silt settles and clay‐size sediment increases in concentration, hydrodynamic lubrication forces strengthen and reduce mobility of the near‐bed part of the flow. This condition is then perturbed by a bedward‐directed outer flow disturbance that dramatically increases frictional stresses and effective fluid viscosity and ultimately shear jamming that causes gelling and deposition of a poorly sorted clay‐rich layer. This process is then repeated multiple times to build up a deposit composed of alternating silt‐rich and clay‐rich laminae overlain by structureless mud deposited directly from suspension.","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135758764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrated petrographical and geochemical study of the Tredian Formation in the Salt and Trans-Indus Surghar ranges, North-West Pakistan: Implications for palaeoclimate","authors":"Kamil Ahmed Qureshi,&nbsp;Muhammad Rizwan,&nbsp;Hammad Tariq Janjuhah,&nbsp;Ihtisham Islam,&nbsp;George Kontakiotis,&nbsp;Ahmer Bilal,&nbsp;Mohamad Arif","doi":"10.1002/dep2.255","DOIUrl":"10.1002/dep2.255","url":null,"abstract":"<p>The Middle Triassic Tredian Formation is well exposed in the western region of the Salt Range. It is mostly composed of sandstone with minor alternations of shales and dolomite. This is the first integrated attempt using petrographical and geochemical features to reveal palaeoclimate during deposition of the Tredian Formation. This work sheds light on the petrographical and geochemical properties of the Tredian sandstone in order to date various layers and evaluate the palaeoclimate. The formation was sampled at two distinct stratigraphic layers for petrographic and geochemical analysis of major and trace elements. The sandstone of the Tredian Formation is sub-feldspathic to feldspathic arenite with sub-angular to rounded grains that are moderately to extensively sorted. The relative proportions of the quartz, feldspars and lithoclasts in the examined sandstone samples shows that the Tredian sediments originated from the interior of the craton during a transitional continental regime. Chemical index of alteration values of 59, chemical index of weathering values of 67, and plagioclase index of alteration values of 74.5 indicate a low to moderate degree of weathering in the Tredian sediment source region. Based on the silica content, SiO₂/Al₂O₃ ratios (2.7–6.1; mean 4.1), and chemical maturity index, it is deduced that the Tredian Formation was deposited in chemically immature to sub-mature and dry to semi-arid conditions. Geochemical proxies indicate the acidic source of sediment and deposition on the passive margin of the Indian Plate. The trace element characteristics of the sediments, especially the Rb/Sr, Cu/Zn, Ni/Co, V/Cr and Sr/Ba ratios, indicate that the sediments originated from the first weathering cycle and support the notion that they were deposited in an oxidising continental environment. A semi-arid to arid palaeoclimate predominated through the Middle Triassic at the north-western passive continental margin of the Indian Plate in the south-eastern Neo-Tethys.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.255","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135758628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Discussion on ‘Middle Jurassic multi-scale transgressive–regressive cycles: An example from the Lusitanian Basin’, by Magalhães et al., Depositional Record, 2023, 9(1), 174–202","authors":"Ana C. Azerêdo,&nbsp;Vânia F. Correia,&nbsp;Ángela Fraguas","doi":"10.1002/dep2.252","DOIUrl":"10.1002/dep2.252","url":null,"abstract":"<p>The paper by Magalhães et al. (<span>2023</span>) concerns the Jurassic coastal outcrop between Consolação and São Bernardino beaches, in the western-central Lusitanian Basin (LB), Portugal (Figure 1). The authors used a sequence stratigraphic approach, defining multi-scale cycles and, based on nannofossils and dinoflagellate cysts (dinocysts) data, they re-assigned the section to the Middle Jurassic ‘Candeeiros Formation’; formerly the section had been established as part of the Upper Jurassic Alcobaça Formation (namely Fürsich et al., <span>2022</span>; Leinfelder, <span>1986</span>; Manuppella et al., <span>1999</span>; Schneider et al., <span>2009</span>; Werner, <span>1986</span>). Although the sedimentology and sequence analysis were detailed, we consider their assessment to be incorrect and oversimplified including, for example, the assigned age of the unit and the top of the section. Moreover, the new fossil data are too briefly discussed and based on limited data, and the local/regional geology is barely discussed.</p><p>The Alcobaça Formation, recently formalised by Fürsich et al. (<span>2022</span>), is an important unit of the Upper Jurassic of the LB (Figure 2). Fürsich et al. (<span>2022</span>) provided an extensive literature overview, in which the formation is thoroughly described, illustrated and correlated within the basin (including the Consolação section); they presented facies analysis, macropalaeontological and micropalaeontological taxonomic and palaeoecological data and palaeogeographical interpretations. However, this seminal work is not mentioned by Magalhães et al. (<span>2023</span>). The Alcobaça Formation is a mixed siliciclastic-carbonate succession; its age is constrained by macrofossil and microfossil data and strontium isotope values, and has been confidently considered to be mainly of Kimmeridgian age, although possible slight age extensions of its base and top have been discussed (Fürsich et al., <span>2022</span>; Kullberg &amp; Rocha, <span>2014</span>; Leinfelder, <span>1986</span>; Manuppella et al., <span>1999</span>; Schneider et al., <span>2009</span>; Werner, <span>1986</span>).</p><p>If the part of the section described by Magalhães et al. (<span>2023</span>) were Middle Jurassic strata, then the local succession would be: the outcrops of Kimmeridgian Alcobaça Formation at the Consolação section, succeeded southwards by the Middle Jurassic (Bathonian/Callovian) ‘Candeeiros Formation’, in turn overlain by the much later Upper Jurassic Lourinhã Formation, the intervening units locally (and implausibly) not present. No considerations of plausible depositional geometries or regional correlations with nearby formations were made to support the drastic sequence changes implied.</p><p>At Cesareda zone, about 9 km eastwards, and at Baleal Peninsula, about 7 km north-westwards (Figure 1), Middle Jurassic carbonate outcrops occur, dated by ammonites from, respectively, Bajocian to Callovian and Bajocian/Bath","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.252","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134947438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Comment on: Magalhães et al., Middle Jurassic multi-scale transgressive–regressive cycles: An example from the Lusitanian Basin, The Depositional Record, 9, 174–202","authors":"S. Schneider,&nbsp;F. T. Fürsich,&nbsp;W. Werner,&nbsp;C. S. Pierce","doi":"10.1002/dep2.253","DOIUrl":"10.1002/dep2.253","url":null,"abstract":"<p>In a recently published paper, Magalhães et al. (<span>2023</span>) re-studied the coastal section between the villages of Consolação and São Bernardino south of Peniche, central Portugal, and determined a novel Bathonian to early Callovian age for the exposed strata. They identified low-frequency to high-frequency transgressive–regressive sequences, and interpreted the depositional settings as offshore to shoreface for siliciclastic strata, with subordinate carbonate intervals associated with inner to outer ramp settings. Based on these new results, they assigned the studied strata to the Candeeiros Formation. We show that these conclusions are based on misinterpretation and the non-consideration of previously published contradictory data.</p><p>The Jurassic sedimentary succession of the Lusitanian Basin is unusually well-exposed along the Atlantic coast, and offers unique opportunities for study. The coastal section between the villages of Consolação and São Bernardino is a prime example, and has been studied repeatedly (Fürsich et al., <span>2022</span>; Mateus et al., <span>2017</span>; Taylor et al., <span>2014</span>; Werner, <span>1986</span>), but a modern sequence stratigraphic analysis of this succession has never been attempted. As such, the study of Magalhães et al. (<span>2023</span>) generally comes as a welcome addition. However, this study falls short in several aspects. Most significantly, its dissonance with previously published contradictory literature is not taken into account, and the interpretation of the data generated is selective and model-driven. We address these issues in the following sections, drawing on the literature, including a recently published study by the present authors (Fürsich et al., <span>2022</span>), accessible online approximately half a year before the submission of the manuscript of Magalhães et al. (<span>2023</span>), but not considered in their paper.</p><p>Magalhães et al. (<span>2023</span>) characterise the geodynamic evolution of the Lusitanian Basin in sufficient detail, and the literature cited in this section is relevant and up to date. However, despite the sequence stratigraphic focus of their study, the sedimentological evolution of the basin is barely addressed. In the context of a presumed Middle Jurassic age for the strata at Consolação, it would have been essential to focus on the Early to Middle Jurassic evolution of depositional environments in the Lusitanian Basin, but the lithostratigraphic scheme used is outdated, and numerous key studies are not cited. Magalhães et al. (<span>2023</span>) use the oversimplified scheme of largely concordant successive Coimbra, Brenha and Candeeiros formations, which was established by Shell Prospex Portuguesa in the 1970s, but never formally published (Witt, <span>1977</span>). This scheme has been superseded by much more detailed lithostratigraphy. In its revised, restricted sense, the Coimbra Formation of Moitinho de Almeida et al. (<span>19","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.253","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134947439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Reply to the discussion and comments of Azerêdo et al. (2023) and Schneider et al. (2023) on the paper by Magalhães et al. ‘Middle Jurassic multi-scale transgressive–regressive cycles: An example from the Lusitanian Basin’, The Depositional Record, 9, 174–202","authors":"Antonio J. C. Magalhães,&nbsp;Gerson J. S. Terra,&nbsp;Felipe Guadagnin,&nbsp;Daniel G. C. Fragoso,&nbsp;Mirian C. Menegazzo,&nbsp;Nuno L. A. Pimentel,&nbsp;Sissa Kumaira,&nbsp;Gerson Fauth,&nbsp;Alessandra Santos,&nbsp;David K. Watkins,&nbsp;Mauro D. R. Bruno,&nbsp;Daiane Ceolin,&nbsp;Simone Baecker-Fauth,&nbsp;Guilherme P. R. Gabaglia,&nbsp;Washington L. E. Teixeira,&nbsp;Francisco P. Lima-Filho","doi":"10.1002/dep2.254","DOIUrl":"10.1002/dep2.254","url":null,"abstract":"<p>We want to acknowledge the comments about our recently published paper. The exchange of ideas, data and interpretation improves our knowledge and is the right way to discuss science's advances.</p><p>This reply considers the points raised by Azerêdo et al. (<span>2023</span>) and Schneider et al. (<span>2023</span>). In both manuscripts, these authors raised many issues about sedimentological and stratigraphic aspects that can be separated into two groups: (a) those related to the age of the studied succession; and (b) those assigning the studied succession to the Candeeiros Formation.</p><p>There is a long tradition of using macropalaeontology in the Lusitanian Basin, and many authors have used macrofossils as palaeoenvironmental indicators and to date sedimentary deposits. However, except for ammonoids, micropalaeontology data are much more accurate than those from corals or bivalves, for example. This is particularly important in the Consolação–São Bernardino succession because of the lack of micropalaeontological and biostratigraphical studies.</p><p>It is noteworthy that Magalhães et al. (<span>2023</span>) presented a hitherto unpublished micropalaeontological and biostratigraphical analysis of the Consolação–São Bernardino succession. The association of two fossil groups (calcareous nannofossil and dinoflagellates) support our biostratigraphic data, in which we performed taxonomic and biostratigraphic analyses with care and due importance. Hence, our analysis assures the age of the studied succession, which confirms the Bathonian<b>–</b>early Callovian age. Azerêdo et al. (<span>2023</span>) and Schneider et al. (<span>2023</span>) questioned our age assignments, but failed to present their micropalaeontological and biostratigraphical analysis for the same Consolação–São Bernardino succession. Moreover, our findings were integrated with facies analysis, ichnofacies, petrography and macrofossil content to support the proposed age. Azerêdo et al. (<span>2023</span>) and Schneider et al. (<span>2023</span>) have no doubts about the taxonomy presented, and their issues about our dating are based on reinterpretations of our data. They assumed that the literature had already defined the age of the studied succession, which we consider is beyond debate as a result of the new data. That paper acknowledged the previous studies in the Consolação-São Bernardino section. Still, the arguments by Azerêdo et al. (<span>2023</span>) and Schneider et al. (<span>2023</span>) are not based on micropalaeontological data collected in the Consolação-São Bernadino section, but rather on correlations with supposed chronoequivalent units that do not consider our new age. Their comments failed to include irrefutable evidence of the Upper Jurassic age based on micropalaeontological data from the Consolação–São Bernardino succession to contrast with dates presented by Magalhães et al. (<span>2023</span>).</p><p>New data bring new interpretations. Even though all i","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135482482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Record of palaeoclimate across the Cretaceous–Palaeogene boundary from palaeosols in the west-central San Juan Basin, New Mexico, USA","authors":"Lawrence H. Tanner,&nbsp;Spencer G. Lucas","doi":"10.1002/dep2.251","DOIUrl":"10.1002/dep2.251","url":null,"abstract":"<p>The mass extinction at the Cretaceous–Palaeogene boundary is widely attributed to sudden and severe climate changes forced by bolide impact and/or flood basalt volcanism. In terrestrial depositional settings, these changes may potentially be recorded by palaeosols. To test the ability of pedogenic features to record both long-term climate and shorter-term changes preceding and following the Cretaceous–Palaeogene extinction event, palaeosols in the Upper Cretaceous (Maastrichtian) Naashoibito Member of the Ojo Alamo Formation and the lower Palaeocene (Danian) Nacimiento Formation in the San Juan Basin of north-western New Mexico, USA, were examined, including data from previous studies. The fine-grained facies of the Naashoibito Member comprises grey to greenish-grey and red-banded mudstones displaying pedogenic features including colour mottling, root traces, cutans, ped fabrics, pedogenic slickensides and calcareous nodules. Aside from a high-chroma horizon at the formation base, palaeosols in the lower Nacimiento Formation are broadly similar to those observed in the Naashoibito Member. Lateral and vertical variability of the pedogenic features between correlated sections suggest that soil hydrology varied spatially and temporally from very saturated to seasonally well-drained, with temporal variations controlled by basin sedimentation rates. Abrupt and/or catastrophic climate events precisely at the Cretaceous–Palaeogene boundary are not recorded due to an unconformity at the top of the Naashoibito Member. However, the presence of kaolinite in the clay mineral assemblage of the Nacimiento Formation, particularly near the formation base, but not in the Naashoibito Member, indicates episodic warmth and short (10⁴ years) intervals of more intense weathering conditions during the very early Danian as compared to the late Maastrichtian. Aside from short warm intervals, the overall palaeoclimate during deposition of both formations was warm and consistently subhumid to humid and seasonal, suggesting no substantial long-term (10⁵–10⁶) climate change took place across the Cretaceous–Palaeogene boundary in the San Juan Basin.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.251","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44824673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Resolving tsunami wave dynamics: Integrating sedimentology and numerical modelling","authors":"Jon Hill,&nbsp;Graham Rush,&nbsp;Jeff Peakall,&nbsp;Michael Johnson,&nbsp;Luke Hodson,&nbsp;Natasha L. M. Barlow,&nbsp;Elisabeth T. Bowman,&nbsp;W. Roland Gehrels,&nbsp;David M. Hodgson,&nbsp;Georges Kesserwani","doi":"10.1002/dep2.247","DOIUrl":"10.1002/dep2.247","url":null,"abstract":"<p>Tsunamis are a major hazard along many of the world's coastlines. To understand the impact of these events, a sufficiently long record of previous events is needed, which can be provided by their sedimentary deposits. A number of past events have left extensive sedimentary deposits that can be used to understand the hydrodynamics of the tsunami. The <i>ca</i> 8.15 ka Storegga submarine slide was a large, tsunamigenic mass movement off the coast of Norway. The resulting tsunami had estimated run-up heights of around 10 to 20 m on the Norwegian coast, over 30 m in Shetland and 3 to 6 m on the Scottish mainland coast. New cores were taken from the Ythan Valley in North-East Scotland, where Storegga tsunami deposits have previously been found. High-resolution sedimentary analyses of the cores, combined with statistical (changepoint) analysis, shows signatures of multiple waves. Moreover, detailed CT scans of the erosional basal surface reveal sole marks called skim marks. Taken in conjunction with the grain size and sedimentary fabric characteristics of the tsunami deposits, this indicates that the flow exhibited a high-concentration basal component, with an initial semi-cohesive phase and that deposition was dominantly capacity driven. A multiple wave hypothesis is tested by creating a high-resolution numerical model (metre-scale) of the wave inundation, coupled to a previously published regional model. The inundation model confirms that multiple waves passed over the site in agreement with the sedimentological analysis. The sensitivity of the model to the reconstructed palaeocoastal geomorphology is quantitatively explored. It is concluded that local palaeogeomorphological reconstruction is key to understanding the hydrodynamics of a tsunami wave group in relation to its sedimentary deposit. Combining sedimentological data with high-resolution inundation modelling is a powerful tool to help interpret the sedimentary record of tsunami events and hence to improve knowledge of their risks.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.247","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44710204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Timing of the initiation and duration of the Cretaceous extensional regime in South-east China: Constraints from growth strata in terrigenous basins","authors":"Xinqi Yu,&nbsp;Jun Hu,&nbsp;Wei Li,&nbsp;Kun Liu,&nbsp;Ran Hao","doi":"10.1002/dep2.250","DOIUrl":"10.1002/dep2.250","url":null,"abstract":"<p>There has been no consensus yet regarding the precise initial timing and duration of the late Mesozoic extensional tectonics in the South-eastern China Block. This work focusses on the growth strata of the Early Cretaceous red beds in the South-eastern China Block to determine the late Mesozoic tectonics and the precise timing of the initiation and duration of extensional tectonics in this area. Field observation of several terrigenous basins shows that the dip angles of the Cretaceous red beds have varied from moderate to gentle from basin edges to interiors (or centres). The visible and estimated thickness within a single bed increases slightly downwards from the upper to the lower part. These characteristics indicate that the sedimentary area of these beds has undergone an extensional process with expansion and deepening of the sedimentary basins. Rotation of the border surfaces (limbs) and downward warping of the hanging walls or retreat of the footwalls of listric normal faults causes three types of extensional growth (or syntectonic) strata in the deposits of different basins. Dating of the volcanic rocks related to the growth beds reveals that the sedimentary basins were enlarged and deepened when the Early Cretaceous strata were deposited in the South-eastern China Block from <i>ca</i> 140 to 137 Ma. Regionally, under the influence of Palaeo-Pacific plate rollback since <i>ca</i> 140 Ma, the South-eastern China Block stress field has led to lithospheric uplift and pull-apart structures near the surface, causing the half-graben basins to receive sedimentation. Although the extensional event was interrupted by a short compressional event during 120 to 105 Ma, with the oceanward retreat of the trench, the area of extension gradually enlarged and rejuvenated south-eastwards until the end of the Cretaceous. This Cretaceous extension event of the South-eastern China Block must belong to a worldwide geological event with global significance.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.250","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49446829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Depositional architecture and sequence stratigraphic framework of the fluvio-lacustrine Ash Shumaysi Formation, Jeddah-Makkah Region, Saudi Arabia: Implications for climatic and tectonic changes in a local-scale sub-basin","authors":"Faisal A. Alqahtani,&nbsp;Murad R. Abdulfarraj,&nbsp;Hamdalla A. Wanas","doi":"10.1002/dep2.248","DOIUrl":"10.1002/dep2.248","url":null,"abstract":"<p>This study aims to interpret and document the depositional architecture styles and sequence stratigraphic framework of the Ash Shumaysi Formation in the Jeddah-Makkah region, the west-central part of Saudi Arabia, and presents an example of rarely discussed, local-scale sub-basins (half grabens). It also shows the relationships between synchronous sedimentary processes and pre, syn and post-rift conditions. The described lithofacies and their facies associations indicate the presence of seven architectural depositional styles: proximal-distal braided fluvial, meandering fluvial (point bar), crevasse splay, floodplain, estuarine and lacustrine. A proposed depositional model for the Ash Shumaysi Formation is drawn. The Ash Shumaysi Formation forms a second order depositional sequence, which is organised into two third order depositional sequences (sequences I and II) bounded by three sequence boundaries. Each third-order sequence encloses the low accommodation systems tract and high accommodation systems tract. The low accommodation systems tract represents the coarse-grained, braided-distal fluvial facies developed during low accommodation space associated with high sediment supply (high discharge). The high accommodation systems tract encloses the fine-grained deposits of point bar, estuarine and lacustrine facies that reflect the creation of significant accommodation space and low sediment supply (low discharge). Vertical and lateral variations of the inferred depositional architectural styles, sequences and systems tracts reflect that tectonic forces and climate are the main controlling factors during deposition of the Ash Shumaysi Formation, although base-level changes in response to sea-level changes cannot be ruled out.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48986679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}