Sedimentology最新文献

{"title":"Universal decomposition model: An efficient technique for palaeoenvironmental reconstruction from grain‐size distribution","authors":"Yuming Liu, Ting Wang, Bo Liu, Yi-Jie Long, Xingxing Liu, Youbin Sun","doi":"10.1111/sed.13115","DOIUrl":"https://doi.org/10.1111/sed.13115","url":null,"abstract":"For many years, researchers have used the decomposition of grain‐size distributions to acquire critical information on provenances, transport dynamics and depositional environments. This study presents a novel decomposition method, termed the universal decomposition model, for analysing grain‐size data. The universal decomposition model unifies single‐sample unmixing and end‐member modelling analysis approaches and overcomes their respective limitations. To evaluate the effectiveness of the universal decomposition model, an artificial dataset and borehole data from the west Weihe Basin were analysed. Results indicate that the universal decomposition model algorithm performs proficiently on both datasets. Correlation analysis was employed to compare the abilities of universal decomposition model, single‐sample unmixing and end‐member modelling analysis to extract minor signals, with universal decomposition model and single‐sample unmixing exhibiting greater proficiency. Furthermore, the universal decomposition model provides a broader perspective for contrasting single‐sample unmixing and end‐member modelling analysis. The study highlights the inadequacy of the statistical method for determining the optimal number of components and summarizes an empirical approach. Moreover, disregarding the potential diversity in component shapes of real‐world sediments has been demonstrated to be a sub‐optimal design. Finally, this article presents results of a new investigation into the geological significance of sediment grain sizes revealed by various analytical methods that suggest that the universal decomposition model has enormous potential in reconstructing paleoenvironment.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"39 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77821594","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":"A mechanistic approach for interpreting hydroclimate from halite‐bearing sediments","authors":"I. Sirota, M. Armon, Yoav Ben Dor, E. Morin, N. Lensky, Y. Enzel","doi":"10.1111/sed.13114","DOIUrl":"https://doi.org/10.1111/sed.13114","url":null,"abstract":"Establishing accurate palaeo‐hydroclimatic reconstructions from lacustrine and marine archives is a long‐standing challenge in palaeoenvironment studies. Closed‐basin evaporites, and especially halite, record episodes of extremely arid conditions during rapid climate change. However, the complex limnological behaviour of deep hypersaline water bodies and the stochastic nature of the hydroclimatic regime and its variations limit detailed palaeo‐hydroclimatic interpretations from such records. Therefore, a mass‐balance model was developed to explore hydrology–limnology–sedimentology relationships in hypersaline environments under both deterministic and stochastic approaches that generates synthetic halite–mud sequences. Applying the model to the Holocene Dead Sea halites yields novel insights into palaeoenvironmental conditions in the Levant. The deterministic framework indicates that: (i) under a series of similar hydroclimatic cycles, the thickness of each subsequent halite interval decreases, due to the depletion of dissolved‐ions storage in the brine; (ii) halite deposition requires lake levels to drop below the minimal lake level of the preceding cycle; (iii) the time interval between halite deposition and the hydrological minimum is increasingly longer in subsequent cycles. Thus, counter‐intuitively, halite deposition mostly takes place as water discharge increases, providing that the water balance is still negative. The stochastic approach produced random sequences comparable to the observed Dead Sea sedimentary record. It demonstrates that some hydrological minima are not represented by halite deposition at all. Furthermore, the thickness and number of halite beds at each hydrological cycle vary substantially, depending on the specific hydrological conditions realized. Finally, these results imply that the major Dead Sea level drop at the pre‐Holocene deglaciation (ca 14 ka bp), previously assumed to be a record minimum, could not have been as pronounced as suggested, and must have been milder than the subsequent drop at the early Holocene (ca 11–10 ka bp).","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"140 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74880938","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":"Deep‐water sand transfer by hyperpycnal flows, the Eocene of Spitsbergen, Arctic Norway","authors":"S. Grundvåg, W. Helland‐Hansen, E. Johannessen, J. Eggenhuisen, F. Pohl, Yvonne T. Spychala","doi":"10.1111/sed.13105","DOIUrl":"https://doi.org/10.1111/sed.13105","url":null,"abstract":"Flood‐generated hyperpycnal flows are dense, sediment‐laden, turbulent flows that can form long‐lived, bottom‐hugging turbidity currents, which undoubtedly transport large volumes of fine‐grained sediments into the ocean. However, their ability in transferring sand into deep‐water basins is debated. This study presents sedimentological evidence of sandy hyperpycnal flow deposits (hyperpycnites) in a series of basin floor lobe complexes associated with a progradational shelf margin in the Eocene of Spitsbergen, Arctic Norway. Four coexisting types of sediment gravity flow deposits are recognized: (i) sandy hyperpycnites deposited by quasi‐steady hyperpycnal flows; (ii) turbidites deposited by waning, surge‐type turbidity currents; (iii) hybrid event beds deposited by transitional flows; and (iv) mass transport deposits emplaced during rare slope failures. The abundance of thick‐bedded massive sandstones, frequent bed amalgamation, the distribution of hyperpycnites across the lobes and the abundance and systematic occurrence of plant‐rich hybrid event beds and associated climbing ripple cross‐laminated beds in the lobe fringes, suggest that hyperpycnal flow was the most important mechanism driving lobe progradation. Shelf‐edge positioned fluvial channels linked to the basin floor lobe complexes via deeply incised, sandstone‐filled slope channels, suggest that rivers fed directly onto the slopes where their dense, sand‐laden discharges readily generated quasi‐steady hyperpycnal flows that regularly reached the basin floor. The composite architecture and complex waxing–waning flow facies configuration of the hyperpycnites is consistent with sustained and concomitant suspension and traction deposition under fluctuating subcritical to supercritical conditions. Similar sandstone beds occur on the clinoform slopes, indicating that the hyperpycnal flows operated likewise on the slope. Plant‐rich hybrid event beds indicate transformation of initially turbulent flows by relative enrichment of clay and plant material via progressive sand deposition to such an extent that it suppressed turbulence. The multi‐faceted character of the hyperpycnites reported here, challenges traditional beliefs that hyperpycnites assumingly preserve the waxing–waning signal of single‐peaked floods.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"1 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77959335","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":"Ultra‐long‐distance transport of aeolian sand: The provenance of an intermontane desert, south‐east China","authors":"Shuo Cao, Laiming Zhang, N. Mountney, Jing Ma, Mingang Hao, Chengshan Wang","doi":"10.1111/sed.13106","DOIUrl":"https://doi.org/10.1111/sed.13106","url":null,"abstract":"Intermontane deserts are an important type of arid‐climate sedimentary system. Although rare at present, the sedimentary records of intermontane deserts reveal their widespread development in past greenhouse periods, and they might develop in the near future in response to ongoing global warming. Determination of the provenance of sand supplied for the construction of intermontane deserts is important to gain improved understanding of the potential impact of future climate on environmental evolution in arid and semi‐arid regions. During the Cretaceous, a typical intermontane desert developed in the Xinjiang Basin, south‐east China. In this study, the origin, spatial variability, and transport pathways of both aeolian and alluvial–fluvial sediments in the Xinjiang intermontane desert are investigated by analyses of bulk‐rock petrography and detrital‐zircon U–Pb geochronology. These results demonstrate that the sand in the Xinjiang intermontane desert succession was mainly of extraneous origin and wind‐derived. The nearby South China Block and South China Magmatic Belt were primary sources, and the 1000 km distant western margin of Yangtze Block was an important secondary source. During the Late Cretaceous, the westerlies were stronger in the northern than in the southern hemisphere with doubled wind speeds. In such a climatic context, the results herein suggest that the ultra‐long‐distance aeolian sediment transport was likely further enabled by two factors: (i) the strengthening of intermittent westerly winds during short‐lived glacial episodes; and (ii) the presence of a low‐relief corridor that served as a transport pathway from source to sink.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"97 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74194727","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":"Shape‐dependent settling velocity of skeletal carbonate grains: Implications for calciturbidites","authors":"A. Slootman, Max de Kruijf, G. Glatz, J. Eggenhuisen, R. Zühlke, J. Reijmer","doi":"10.1111/sed.13103","DOIUrl":"https://doi.org/10.1111/sed.13103","url":null,"abstract":"Particle transport and deposition in turbidity currents is governed by the balance between turbulent suspension and gravitational settling, with settling velocity becoming dominant during the final rain‐out phases of decelerated turbidity currents on lobes. Differential particle settling velocities play a role in the sorting of grains in turbidity currents; there is a preference of grains with higher settling velocities to be deposited first, yielding a settling‐velocity gradient in vertical and longitudinal cross‐sections through turbidite beds. If sediments contain little variation in particle shape and density (for example, siliciclastics), then settling velocity is dominantly controlled by grain size. Carbonate sediments, in contrast, are composed of non‐skeletal and skeletal grains with various growth structures, producing a wide distribution of particle shapes (from spheroidal to platy, bladed and elongated forms). The present paper aims to constrain the extent to which shape‐dependent differential settling velocities influence sorting mechanisms in carbonate turbidity currents. Experiments using natural skeletal sand were conducted to investigate the settling of carbonate grains in: (i) isolation; (ii) suspension clouds; and (iii) turbidity currents. Size, density and shape parameters, including Corey Shape Factor and Zingg diagrams, were analysed using high‐resolution micro‐computed tomography. The slower settling of non‐spheroidal shapes was quantified. In the sinking suspensions, a sorting mechanism operated through differential velocities yielding an abundance of spheroidal grains at the base and enrichment in less‐spheroidal grains towards the top of suspension deposits. This trend was also observed longitudinally in carbonate turbidity currents, for which enhanced advection lengths caused less spheroidal grains to be transported farther into the basin. The effect of particle shape becomes increasingly significant as grain size increases, in particular above medium sand. Carbonate turbidites may therefore be more poorly sorted than siliciclastic turbidites, which is expected to result in lower primary porosity in calciturbidites compared to siliciclastic turbidites.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"56 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83159715","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":"Orbitally‐driven Palaeogene to Neogene deposition in the western South Atlantic (Espírito Santo Basin) and its correlation with global sea level","authors":"T. Santos, Luana Lisboa, Victor Carreira, Fellippe R. A. Bione, I. Venancio, M. Bernardes, A. Belém, R. Díaz, M. Moreira, Alexandre A. O. Lopes, T. L. Santos, I. Souza, A. Spigolon, A. Albuquerque","doi":"10.1111/sed.13104","DOIUrl":"https://doi.org/10.1111/sed.13104","url":null,"abstract":"Over the last 66 million years, Earth has undergone dramatic climate changes, shifting from a warm greenhouse to the more recent cold icehouse with polar ice caps in both hemispheres. Geological records show that the transition between these equilibrium states caused significant long‐term eustatic sea‐level and atmospheric CO2 decline paced by external orbital motions. Such eustatic variability influenced the stacking pattern of sedimentary successions, generating cyclic sequence boundaries that may be globally correlated. However, the impact of such oscillation along the Brazilian margin is largely unknown. This study used the natural gamma‐ray log from a well (ES‐2) at the offshore Espírito Santos Basin (western South Atlantic) measured between late‐Palaeocene and late‐Miocene. Null hypothesis tests ‐ evolutionary Average Spectral Misfit and Correlation Coefficient of no orbital modulation ‐ were executed to confirm the influence of astronomical parameters. The evolutionary Time Optimization algorithm was used to extract the sedimentation rate and depositional time. The anchored timescale shows a chronological interval placed between 58.97 and 7.72 ± 0.1 Ma (mid‐Thanetian – late Tortonian), mostly influenced by long‐eccentricity and short‐eccentricity (405 kyr and ca 100 kyr, respectively) and obliquity (ca 40 kyr) and their respective amplitude modulations (ca 2.4 Myr and 1.2 Myr). Applying the Integrated Prediction Error Filter Analysis and a high‐resolution age model, this study identified main depositional trends through time and correlated them to global sea‐level change. The correlation indicates that several intervals of global sea‐level reduction agree with a regressive trend at the ES‐2 site, but this relation is affected during enhanced regional tectonic activity intervals, as related to the emplacement of the Abrolhos Archipelago. The strategy adopted here is a way to join cyclostratigraphy and sequence stratigraphy, and promotes high‐resolution local‐to‐global correlation by identifying key stratigraphic surfaces. This will be relevant for palaeoclimatic studies and the geoscientific industry.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"40 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79793101","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":"Century‐scale sequences and density‐flow deltas of the late Holocene and modern Dead Sea coast, Israel","authors":"M. Moran, J. Holbrook, N. Lensky, Liran Ben Moshe, Z. Mor, H. Eyal, Y. Enzel","doi":"10.1111/sed.13101","DOIUrl":"https://doi.org/10.1111/sed.13101","url":null,"abstract":"Late Holocene Dead Sea rift‐margin strata reveal century‐scale sequences. Sequences are known to form at millennial timescales, but whether they can form at scales as short as centuries (seventh‐order, sensu Vail et al., 1991) was previously unconfirmed. This study maps lithofacies and sequence‐stratigraphic surfaces from a ca 35 m high outcrop of the post‐1500 ad part of the Holocene falling‐stage wedge, and adjacent subaerial environments, along the Nahal Darga of the western Dead Sea coast, using drone images. The study also produces the first maps of subaqueous delta environments from remotely operated vehicle photographs. Comparison of outcrop and remotely operated vehicle data show that delta foresets form by debris‐flow lobes accreting onto the delta face. Debris lobes increase in size with depth, have sorted cobble heads, and stack compensationally. Debris lobes dewater to form mostly erosive turbidity currents that cut channels and obstacle scours down slope. Topsets comprising fluvial, beach‐ridge and lagoonal deposits prograde over these foresets. Surfaces separating foreset and topset elements of this Gilbert‐delta system bind systems tracts and record downstep and upstep of the shoreface associated with base‐level rises and falls. These surfaces match known lake‐level changes in the Dead Sea in magnitude, timing and direction. They confirm Medieval (ca 600 to 1300 ad) and Modern (ca 1300 ad to Modern) century‐scale sequences. These microsequences form in the Dead Sea because this climate‐sensitive lake can generate metres‐scale lake‐level cycles on century timescales, and because depositional systems can, as shown here, reestablish sufficiently rapidly (≤101 years) to record century‐scale cycles with complete systems tracts. Although conditions for generating microsequences are optimal in the Dead Sea, they are not unique. These microsequences pose a challenge to sequence stratigraphy because they typically fall below seismic resolution, may geometrically resemble higher‐order composite sequences and complicate defining of anchor sequences within a sequence hierarchy.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"29 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76186767","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":"Aptian Oceanic Anoxic Event 1a in the shallow, carbonate‐dominated intrashelf Kazhdumi Basin, Zagros Mountains","authors":"A. Jafarian, A. Husinec, Chengshan Wang, Xi Chen, Abdus Saboor, Yalin Li","doi":"10.1111/sed.13102","DOIUrl":"https://doi.org/10.1111/sed.13102","url":null,"abstract":"The early Aptian Selli Oceanic Anoxic Event 1a (ca 120 Ma) is a major Mesozoic episode of biotic, climatic, environmental and geochemical perturbations associated with the extensive burial of organic matter. Based on the new sedimentological, biostratigraphic and carbon‐isotope data from the Kazhdumi Intrashelf Basin, this study tracks the Oceanic Anoxic Event 1a‐associated perturbations along the north‐eastern margin of the Arabian Plate. The studied succession has five complete third‐order sequences with three facies associations: (i) deep open‐marine and intrashelf basin; (ii) shallow open‐marine mid‐ramp; and (iii) inner ramp. The Oceanic Anoxic Event 1a‐equivalent deposits include the former two facies associations – (i) and (ii) – and are 25 to 31 m thick, which corresponds to the accumulation rates of ca 1.9 to 3.1 cm kyr−1 (uncorrected for compaction) based on the 1.0 to 1.3 Myr duration of the event. The interval retained a high‐resolution record of carbon‐isotope and sea‐level fluctuations, which enables correlation across the Arabian Plate and Tethys. The Oceanic Anoxic Event 1a onset is marked by a biotic change from ostreid‐dominated shallow‐marine limestone with abundant foraminifera (Palorbitolina lenticularis and Choffatella decipiens) to dark grey deep‐water planktonic foraminifera‐rich and radiolaria‐rich limestone with chert and organic‐rich shale (Radiolarian Flood Zone). The upper oceanic anoxic event part of 1a is characterized by the shallowing‐upward, backstepping facies marking the return to a shallow open‐marine setting, albeit without recovery of the Palorbitolina–Choffatella association. Deep open‐marine deposition (Kazhdumi Tongue) was restored early during the Oceanic Anoxic Event 1a recovery in the latest early Aptian. A return to shallow open‐marine environments with Mesorbitolina‐rich limestone marks the beginning of the late Aptian, followed by a major sea‐level fall and karstification. This study resolves some of the uncertainties related to the order and timing of the events influencing the environmental disturbances across the eastern Arabian Plate during Oceanic Anoxic Event 1a and stresses the importance of shallow carbonate‐dominated intrashelf basins as faithful recorders of carbon‐isotope and sea‐level oscillations and palaeoenvironmental changes during global oceanic perturbations.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"33 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78896435","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":"Geomorphic and environmental controls on microbial mat fabrics on Little Ambergris Cay, Turks and Caicos Islands","authors":"N. Stein, J. Grotzinger, D. Quinn, U. Lingappa, T. Present, E. Trower, M. Gomes, E. Orzechowski, M. Cantine, K. Metcalfe, W. Fischer, B. Ehlmann, J. Strauss, A. Knoll","doi":"10.1111/sed.13100","DOIUrl":"https://doi.org/10.1111/sed.13100","url":null,"abstract":"To interpret microbially influenced paleoenvironments in the sedimentary record, it is crucial to understand what processes control the development of microbial mats in modern environments. This article reports results from a multiyear study of Little Ambergris Cay, Turks and Caicos Islands, an uninhabited island floored by broad tracts of well‐developed microbial mats on the wind‐dominated and wave‐dominated Caicos Platform. Uncrewed aerial vehicle‐based imaging, differential global positioning system topographic surveys, radiocarbon data, and in situ sedimentological and microbial ecological observations were integrated to identify and quantify the environmental factors that influence the distribution and morphologies of Little Ambergris Cay microbial mats, including their response to large storm events. Based on these data, this study proposes that Little Ambergris Cay initially developed from the accretion and rapid lithification of carbonate sediment delivered by converging wave fronts in the lee of adjacent Big Ambergris Cay. Broad tracts of microbial mats developed during late Holocene time as the interior became restricted due to beach ridge development. Minor elevation differences regulate subaerial exposure time and lead to three categories of microbial mats, differentiated by surface texture and morphology: smooth mats, polygonal mats and blister mats. The surface texture and morphology of the mats is controlled by subaerial exposure time. In addition to elevation, the spatial distribution of mats is largely controlled by hydrodynamics and sediment transport during large storm events. This detailed assessment of the controls on mat formation and preservation at Little Ambergris Cay provides a framework within which to identify and understand the interactions between microbial communities and sediment transport processes in ancient high‐energy carbonate depositional systems.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"53 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82020035","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":"Influence of the grain shape and packing texture on the primary porosity of sandstone: Insights from a numerical simulation","authors":"Yiming Yan, Liqiang Zhang, Xiaorong Luo, Keyu Liu, Tongye Jia, Yanjun Lu","doi":"10.1111/sed.13098","DOIUrl":"https://doi.org/10.1111/sed.13098","url":null,"abstract":"Sandstone is an important carrier of underground hydrocarbon and the geological sequestration of carbon dioxide. Primary porosity is an important parameter used to predict reservoir quality, and it is influenced by the grain shape, grain‐size distribution and grain packing texture. However, few studies have focused on deriving multivariate equations of the grain size, grain‐size distribution and grain packing texture to predict the primary porosity of sandstone. The natural sedimentary process of sandstones was designed and simulated using a discrete element method. The results confirmed that the primary porosity is influenced by roundness, flatness, elongation, grain‐size distribution and grain packing texture; of the attributes, the mean grain size contributes less to the primary porosity of sandstone. Based on 193 simulated sandstone samples with a one‐component grain packing texture, a mathematical model considering roundness, flatness, elongation, grain packing texture and grain‐size distribution was proposed. The maximum, mean absolute and root mean square errors were 0.71, 0.26 and 0.32, respectively. The correlation coefficient between the simulated results and mathematical predicted results was 0.94. Furthermore, the primary porosity was positively correlated with the kurtosis of the grain‐size distribution in sandstone with the same grain shape but different kurtosis. The primary porosity was found to be independent of the mean grain size and mainly affected by the grain packing texture. Moreover, the primary porosity prediction model for sandstones with different grain‐size distribution curves based on the grain packing texture, which was proposed by the author in a previous study, was verified, and the correlation coefficient between the simulated results and predicted results was >0.92. The new mathematical model proposed in this study is a useful supplement for key parameter acquisition in the previous primary porosity prediction model of sandstone with different grain‐size distribution curves and grain packing texture. A mathematical model considering roundness, flatness, elongation, grain packing texture and grain‐size distribution is of great significance for reservoir quality prediction and conducting a quantitative evaluation of the diagenesis.","PeriodicalId":21838,"journal":{"name":"Sedimentology","volume":"83 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88215236","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}