Sedimentary Geology最新文献

{"title":"Thermal maturity and colors of Cretaceous East Asian fossil eggs","authors":"Seung Choi ,&nbsp;Shukang Zhang ,&nbsp;Noe-Heon Kim ,&nbsp;Jin Jung Kweon ,&nbsp;Kohei Tanaka ,&nbsp;Katsuhiro Kubota ,&nbsp;Yuong-Nam Lee ,&nbsp;Junfang Xie ,&nbsp;In Sung Paik ,&nbsp;Sung Keun Lee","doi":"10.1016/j.sedgeo.2025.106855","DOIUrl":"10.1016/j.sedgeo.2025.106855","url":null,"abstract":"<div><div>Several factors influence the quality of fossil preservation, with temperature being one of the key variables. The maximum temperature that fossils have experienced during their taphonomic history affects their thermal maturity and color. Cretaceous fossil eggs of amniote vertebrates from East Asia were analyzed using Raman spectroscopy to investigate their thermal maturity. Eggs from inland regions of East Asia (Mongolia and inland China) do not show a significant thermal imprint, while eggs from the southern and eastern regions of East Asia (coastal China, Korea, and Japan) show a high thermal maturity. Although this pattern must have been caused by the combined effect of complex factors (e.g., burial depth, stratigraphic position, and local geothermal phenomenon), the rollback of the Paleo-Pacific Plate during the Cretaceous and consequent vigorous igneous activity and/or high heat flow near the subduction boundary may have been one of the main working factors. The approach of this study can be extended to fossil eggs from other continents to elucidate the relationship between thermal maturity and geological setting, and will provide a deeper understanding of fossil egg taphonomy.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"481 ","pages":"Article 106855"},"PeriodicalIF":2.7,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725983","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":"Arc-continent collision as recorded in modern stream sand from Oecusse (Timor Island)","authors":"Victor A.S. Vicente ,&nbsp;Pedro Dinis ,&nbsp;Eduardo Garzanti ,&nbsp;Alberto Resentini ,&nbsp;Marta Barbarano ,&nbsp;Marina Cabral Pinto ,&nbsp;João Pratas","doi":"10.1016/j.sedgeo.2025.106852","DOIUrl":"10.1016/j.sedgeo.2025.106852","url":null,"abstract":"<div><div>The small territory of Oecusse in Timor Island has extremely complex geology, influenced by the collision of the Australian continent with the Banda Arc. In Oecusse, sedimentary, volcanic and metamorphic units associated with the lower plate Australian continental margin, the upper plate Banda Terrane, and synorogenic sedimentary successions are exposed. In this study, geochemistry, petrography, and heavy-mineral data on fluvial bedload sand transported by first- and second-order streams are used to better understand the status of arc-continent collision in Timor and the geological nature of the terranes involved in this tectonic process. The presence of upper mantle outliers in Oecusse is readily revealed by serpentinite grains, a heavy mineral assemblage with enstatite, olivine and Cr-spinel, and by Cr, Fe, Sc, Ti, and V concentrations comparable to the Primitive Mantle standard. Volcanic sources occur both in the Banda Terrane and Australian continental margin. The Manamas Formation (Miocene, Banda Terrane) is the most prominent volcanic source, shedding detritus dominated by mafic volcanic rock fragments, plagioclase, and clinopyroxene, with a geochemical signature similar to the Primitive Mantle. The volcanic units of the Barique Formation (Eocene-Miocene, Banda Terrane) and the Maubisse Formation (Permian, Australian continental margin) comprise compositionally heterogenous suites and are intercalated with sedimentary successions, delivering more felsic material, as indicated by the diversified assemblages of lithic fragments and heavy-minerals. Geochemically, they are characterised by lower contents of most compatible elements, higher contents of Th, Y and REE, steeper REE profiles, and stronger negative Eu anomaly than Manamas-derived detritus. These petrographic and geochemical features locally reveal a major felsic volcanic component in the Barique Formation, which cannot be related to the ongoing orogeny because of its proposed late Eocene to early Miocene age. With the exception of coastal sectors where the Manamas Formation is widely exposed, volcanic, sedimentary and low-rank meta-sedimentary rocks partially derived from the Australian lower plate tend to prevail, confirming that arc-continent collision is still at an early stage in the western part of Timor Island.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"481 ","pages":"Article 106852"},"PeriodicalIF":2.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654776","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":"Origin and deposition of deepwater homogenites from a sedimentological perspective: Examples from offshore SW Taiwan","authors":"Radha Krishna Pillutla ,&nbsp;Andrew Tien-Shun Lin ,&nbsp;Jen-Chu Yeh ,&nbsp;Gueorgui Ratzov ,&nbsp;Nathalie Babonneau ,&nbsp;Shu-Kun Hsu ,&nbsp;Chih-Chieh Su ,&nbsp;Serge Lallemand ,&nbsp;Ludvig Löwemark","doi":"10.1016/j.sedgeo.2025.106854","DOIUrl":"10.1016/j.sedgeo.2025.106854","url":null,"abstract":"<div><div>A giant piston core, MD18–3548 (20.07 m) was collected from a perched basin in the Taiwan accretionary wedge, at a water depth of 1752 m. Detailed grain-size analysis, ¹⁴C accelerator mass spectrometry (AMS) dating, and computed tomography (X-CT) scans of the core were performed. Four types of lithofacies, namely hemipelagic sediments, silty turbidite-homogenites, turbidites, and thin silty layers, are identified, along with seventeen event beds. A total of fourteen ¹⁴C AMS dating were carried out, with the depositional ages of the event beds being calculated based on the sedimentation rate of hemipelagites. The oldest event bed is ∼12 cal kyrs BP, while the youngest event bed is ∼64 cal yrs BP. All seven homogenite units are floored by a thin (usually &lt;10 cm thick), coarsening-upward first and then fining-upward unit, capped by a thick structureless mud totally devoid of bioturbation. The average thickness of homogenite units is ∼150 cm, while the thickest homogenite unit is ∼200 cm. These homogenite units can be compared to similar deposits reported elsewhere and find particularly that these units exhibit a basal layer with gradual coarsening and fining upward trend in grain size. We therefore propose a new depositional model for the silty turbidite-homogenite units in seismically-shaken enclosed basins. This model takes into account the coarsening-then-fining upward deposition of the basal layers, reported for the first time.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"480 ","pages":"Article 106854"},"PeriodicalIF":2.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551819","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":"Trace element and OH content of quartz grains in the Amazon river: Potential application in provenance analysis","authors":"R. Stalder ,&nbsp;D. Jaeger ,&nbsp;S. Andò ,&nbsp;E. Garzanti ,&nbsp;C.M. Chiessi ,&nbsp;A.O. Sawakuchi ,&nbsp;T. Ludwig ,&nbsp;M. Strasser","doi":"10.1016/j.sedgeo.2025.106853","DOIUrl":"10.1016/j.sedgeo.2025.106853","url":null,"abstract":"<div><div>Quartz grains in sediment carried by the Amazon River and five of its major tributaries were analyzed by FTIR-spectroscopy and secondary ion mass spectrometry to evaluate their potential for provenance analysis. Additionally, heavy mineral analysis was performed in the same samples to support sediment discrimination and provenance interpretation. Average defect water contents in quartz grains carried by branches with headwaters draining the Andes are higher (Solimões River 8.8 wt ppm, Madeira River 7.2 wt ppm) than in branches exclusively draining cratonic areas (Xingu River 6.5 wt ppm, Tapajós River 4.6 wt ppm, Negro River 4.7 wt ppm); values in one Amazon mainstem sample are intermediate with prevalence of the Andean signal (7.7 wt ppm). The average defect water content correlates to the fraction of grains that are defect-water rich (&gt; 10 wt ppm), ranging from 30 to 40 % for the Solimões, Madeira, and Amazon Rivers down to 10–20 % for the Tapajós and Negro Rivers. The average molecular-water signal exhibits a much clearer contrast than the OH-defect signal. Grains from cratonic tributaries (Negro, Tapajós and Xingu rivers) exhibit significantly weaker molecular water signals than grains from Andean tributaries (Solimões and Madeira rivers); slightly weaker than the latter is the signal from grains in the Amazon mainstem, reflecting a mixture of Solimões and Negro rivers quartz in the Amazon mainstem sample.</div><div>In contrast, trace-element concentrations widely overlap among samples, preventing any robust discrimination about the sources of quartz grains. Trace metals show a fair correlation between Li and Al in all samples; a weak correlation between Al and Ti (indicative of igneous origin) was observed in Negro, Xingu and Amazon River sands, but not in Solimões, Madeira and Tapajós sands. Boron correlates with Li in Tapajós river and Amazon mainstem samples and with Al in Madeira and Tapajós samples.</div><div>Heavy-minerals are mostly amphibole, epidote, augitic clinopyroxene and hypersthene in Solimões River sands largely derived from the Andes, and andalusite, amphibole and epidote in Madeira River sands. Cratonic tributaries contribute durable tourmaline and zircon with andalusite (Negro River) or staurolite and topaz (Tapajós River).</div><div>The higher content of OH defects and molecular water in quartz grains derived from the Andes than in those from cratonic areas indicates that this property can provide useful complementary information to discriminate the source of quartz grains, one of the thorniest tasks in provenance analysis.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"480 ","pages":"Article 106853"},"PeriodicalIF":2.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551818","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":"Geochemical composition and grain size of surface sediments from reticulate dunes in the Tengger Desert, China","authors":"Junguang Wang ,&nbsp;Zhibao Dong ,&nbsp;Zhengcai Zhang ,&nbsp;Rongliang Liu ,&nbsp;Jiqiao Shi ,&nbsp;Ping Lü","doi":"10.1016/j.sedgeo.2025.106851","DOIUrl":"10.1016/j.sedgeo.2025.106851","url":null,"abstract":"<div><div>Reticulate dunes are the prevalent type of dunes found in deserts worldwide. However, compared to other dune types, systematic research on reticulate dunes remains limited, and aspects such as their formation mechanisms, grain size characteristics, and elemental composition characteristics remain inadequately understood. This study integrated regional wind regime data to analyse the grain size characteristics of reticulate dunes (specifically, the primary and secondary ridges) in the Tengger Desert, Considering both primary and sub-wind seasons. Additionally, we examined the elemental composition characteristics and degree of weathering of these dunes. The results indicate that the primary and secondary ridges of the reticulate dunes in the Tengger Desert are predominantly composed of fine sand and very fine sand with a mean grain size of 2.52Φ. Compared with other deserts in China and abroad, the sediments exhibit relatively finer grain sizes and better sorting. Furthermore, the grain size characteristics of surface sediments in the primary and secondary ridges exhibited two distinct distribution patterns during different wind seasons, indicating differences in the formation mechanisms of the primary and secondary ridges. The major elements in the surface sediments of the reticulate dunes in the Tengger Desert are SiO₂ and Al₂O₃, while the predominant trace elements are primarily Ba, Sr, Zr, and Cr. This indicates that the geochemical composition of the sediments is influenced not only by the intrinsic characteristics of the elements but also by the regional climate and the supply of fresh materials, which are significant factors affecting their chemical behavior and content differences. The chemical weathering indices (CIA, residual coefficient, and ICV), along with the A-CN-K and A-CNK-FM triangular diagrams, suggest that the sedimentary environment of the reticulate dune sediments in the Tengger Desert is characterised by a cold, dry climate with a low degree of weathering. The weathering process occurs during the initial stages of plagioclase chemical weathering. These findings lay the foundation for further research on the formation mechanisms, evolutionary processes, and sedimentary environments of reticulate dunes, contributing to a deeper understanding of these complex geomorphological features.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"480 ","pages":"Article 106851"},"PeriodicalIF":2.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551817","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":"The importance of sedimentary structures in fine-grained deposits in re-interpreting the Facies mosaic of Lower Triassic tide-influenced deltas","authors":"Ibrahim Zallum","doi":"10.1016/j.sedgeo.2025.106850","DOIUrl":"10.1016/j.sedgeo.2025.106850","url":null,"abstract":"<div><div>Despite considerable progress in their description and characterization, tide-dominated deltas remain the least understood of the three main delta classes. Fine-grained sediments of the deltaic subenvironments remain particularly understudied, especially via ultra-thin section analysis. Such analysis can aid in identifying subenvironments typically missed in paleodelta analysis (e.g., delta plains). Combined with other methods, they can prove valuable in evaluating depositional and sequence-stratigraphic models and exploring the interplay between sediment supply and channel morphologies.</div><div>This study focuses on the Lower Triassic Torrey Member of the Moenkopi Formation of southern Utah. Previous interpretations posit that the Torrey Member represents a tide-dominated delta deposited in three depositional sequences. Integrating mudstone thin section analysis helped reveal that the Torrey Member contains ten facies associations, with the facies architecture indicating deposition by tide-dominated or tide-influenced deltas over a single depositional sequence. The progradational phase is notable for its decreased channel density and concurrent increase in subaerial exposure indicators. This study posits that hyperycnal flows, including bedload transport, dominated deposition in the prodelta and delta front of the Torrey Member, with no direct evidence of tidal processes.</div><div>This study broadly demonstrates the importance of integrating mudstone thin-section analysis in paleodelta studies. This paper particularly draws particular attention to delta plain identification in semi-arid and arid settings and suggests that thin-section analysis may reveal examples previously missed in similar paleodeltas.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"480 ","pages":"Article 106850"},"PeriodicalIF":2.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562081","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":"Carbonate sedimentation and early diagenesis of the Doushantuo Formation, South China: A window into the terminal Proterozoic","authors":"Min Ren","doi":"10.1016/j.sedgeo.2025.106847","DOIUrl":"10.1016/j.sedgeo.2025.106847","url":null,"abstract":"<div><div>Precambrian marine carbonates with distinct sedimentary fabrics and structures provide valuable insights into the chemical and biological conditions of early oceans. To better understand shallow marine environments approaching the terminal Proterozoic, this study examines carbonate deposits from the Ediacaran Doushantuo Formation across the shoal-rimmed Yangtze platform in South China. These mimetically dolomitized rocks comprise facies of micropeloidal leiolite, grainstone-packstone, micropeloidal and microlaminated leiolites, stromatolite, and mudstone, representing a transition from the upper slope and platform margin environments to the back-shoal peritidal system. The grainstone-packstone facies features large intraclasts of incipient aragonite and high-Mg calcite cements, along with radial ooids that are &lt;2 mm in diameter, all exhibiting varying degrees of microbial micritization. The peritidal facies, marked by abundant microbialites, are dominated by micropeloidal-microlaminated leiolites from the intertidal zone and stromatolites and dolomudstones from deeper waters. Abundant fibrous dolomites (fascicular and radial length-slow, up to 5 mm long) fill cavities in the peritidal facies, particularly within microbial mat cracks. Developed on a warm-temperate to tropical shelf, the rapid early lithification of Doushantuo sediments indicates a high degree of seawater supersaturation during the late Neoproterozoic compared to modern conditions. The remarkable diversity in the physical properties of the Doushantuo carbonates reflects an increased compartmentalization of processes governing carbonate formation and dissolution in shallow marine environments. This shift corresponds with the evolving chemical and biological conditions of the Precambrian ocean, which increasingly emphasized microbial roles in dolomite precipitation. By the terminal Proterozoic, platform carbonate formation became more susceptible to local fluctuations affecting saturation states and kinetic conditions, largely influenced by microbial activity.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"479 ","pages":"Article 106847"},"PeriodicalIF":2.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527170","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":"Sedimentology of a drowned carbonate platform from the Sciacca area (southwestern Sicily): Insights into the Jurassic palaeogeography of Western Tethys","authors":"Francesca Petrella,&nbsp;Simona Todaro,&nbsp;Carolina D'Arpa,&nbsp;Attilio Sulli","doi":"10.1016/j.sedgeo.2025.106839","DOIUrl":"10.1016/j.sedgeo.2025.106839","url":null,"abstract":"<div><div>A sedimentological-stratigraphic study of the Mesozoic carbonates exposed in two inactive quarries in southwestern Sicily has provided new insights into the palaeogeographic evolution of the southern sector of the Western Tethys margin during the Jurassic.</div><div>The Lower–Upper Jurassic succession consists of shallow-water peritidal carbonates, intersected by neptunian dykes and sills, which transition upwards into condensed pelagic limestone. Microfacies analysis of the shallow-water peritidal carbonates has led to their reassignment to the Hettangian–Pliensbachian (<em>p.p.</em>), previously attributed to the Late Triassic. Furthermore, variations in biodiversity within these stratigraphic horizons reflect the survival and recovery interval following the end-Triassic mass extinction event.</div><div>The abrupt transition to condensed pelagic limestone indicates the drowning of the carbonate platform. Lateral facies variations observed within the condensed pelagic limestone suggest different sedimentological processes, influenced by a complex system of structural highs and basins related to the Pangea continental rift. The presence of distinctive micro- and macrofacies, such as micritic oolites and Fe<img>Mn hardgrounds, indicates a varied palaeotopographic setting for each section, where sedimentation is further controlled by bottom-current activity and low sedimentation rates.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"479 ","pages":"Article 106839"},"PeriodicalIF":2.7,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519138","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":"Stratigraphic architecture of a multi-sourced, Deepwater lobe complex (early Permian, Paraná basin, Brazil)","authors":"Sérgio Francisco Leon Dias ,&nbsp;Fernando Farias Vesely ,&nbsp;Ronaldo Paulo Kraft ,&nbsp;Giovana Rebelo Diório ,&nbsp;Guillan Diedrichs Fayad","doi":"10.1016/j.sedgeo.2025.106838","DOIUrl":"10.1016/j.sedgeo.2025.106838","url":null,"abstract":"<div><div>The Rio Segredo Member of the Taciba Formation (Paraná Basin, Brazil) represents a unique example of a multi-sourced turbidite lobe complex, providing valuable insights into the stratigraphic architecture and depositional processes of delta-fed submarine ramp systems. This study investigates the lobe complex, which extends over 120 km and reaches a thickness of up to 40 m, with a focus on bed type distribution, facies associations, and stratigraphic architecture. Through the analysis of 16 measured sections and detailed facies analysis, 14 distinct bed types were identified, including turbidites (TBDs), hybrid event beds (HEBs), and slump and blocky flow deposits (MTDs). These beds are organized into four sub-environments: lobe axis, lobe off-axis, lobe fringe, and distal lobe fringe, reflecting a compensational stacking pattern with lobe centroids shifting southward by an average of 25 km. Paleocurrent data indicates predominant flow directions to the northwest (320°) and southwest (235°), supporting the interpretation of a multi-sourced system. The lobe complex is interpreted as a delta-fed submarine ramp, with deposition driven by delta-front instabilities and hyperpycnal flows via conduits connected to prograding delta. Hybrid event beds, which are common in the basal sandy portion of the succession, are linked to substrate erosion and interactions with small-scale morphological highs, highlighting the influence of paleophysiography on flow dynamics. This study enhances the understanding of multi-sourced turbidite systems and provides a framework for identifying similar systems in other basins. The findings underscore the importance of autogenic controls, such as lobe avulsion and topographic compensation, in shaping the stratigraphic architecture of delta-fed turbidite systems.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"479 ","pages":"Article 106838"},"PeriodicalIF":2.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474421","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":"Depositional systems constraining the distribution of hydrothermal dolostone geobodies: A case study of Permian Guadalupian dolostone in the eastern Sichuan Basin","authors":"Lu Shi ,&nbsp;Ziye Lu ,&nbsp;Fei Li ,&nbsp;Hairuo Qing ,&nbsp;Wenzhuo Jiang ,&nbsp;Wei Li ,&nbsp;Zenghua Li ,&nbsp;Ning Ye ,&nbsp;Bei Zhu ,&nbsp;Qi Tang ,&nbsp;Haizhou Qu ,&nbsp;Yang Xiao ,&nbsp;Shaonan Zhang","doi":"10.1016/j.sedgeo.2025.106837","DOIUrl":"10.1016/j.sedgeo.2025.106837","url":null,"abstract":"<div><div>Lithological heterogeneity can be an important factor in regulating the spatial distribution of hydrothermal dolostone (HTD) geobodies. Understanding HTD genesis is crucial for improving our ability to predict subsurface HTD occurrence within sedimentary frameworks. This study investigates HTD development within the Permian Guadalupian carbonate successions of the eastern Sichuan Basin, China, providing significant insights into HTD formation processes. Through systematic sedimentological analysis of four outcrop sections (Fangniuba, Shangping, Tuotuoba, and Wuyangba), we identified eight distinct lithofacies and five lithofacies associations (LA1–LA5). Integrating field observations with data from adjacent sites, we performed a comprehensive evaluation of the depositional sequences, sedimentary environments, and petrophysical properties of the Guadalupian carbonate strata. These carbonates display a distinctive shallowing-upward sequence overlain by a deepening-upward succession. Notably, Guadalupian dolostones are consistently hosted within the middle portions of the shallowing-upward sequences across all studied sections. Petrological and mineralogical analyses further reveal preferential dolomitization in thin- to medium-bedded wackestone containing nodular cherts (LA2), which served as lateral conduits for hydrothermal fluid migration. Enhanced fracturing is observed within these lithologies, particularly along bedding planes and around nodular chert margins, reflecting their greater susceptibility to petrophysical modification. This preferential dolomitization reflects the interplay of carbonate texture, rock permeability, and fracture susceptibility, which collectively establish optimal diagenetic conditions for fluid-rock interaction. Our findings demonstrate that depositional lithological heterogeneity constrains HTD distribution through two key pathways: (1) primary lithological controls (including permeability variations and mud content), and (2) mechanically influenced properties (particularly bed thickness and nodular cherts). This heterogeneity, established during initial deposition to shallow-burial phases, fundamentally preconditioned subsequent HTD formation and distribution during later hydrothermal fluid emplacement.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"479 ","pages":"Article 106837"},"PeriodicalIF":2.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519137","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}