Sedimentary Geology最新文献

{"title":"‘Reciprocal bioturbation’: A high-frequency low-order sequence-stratigraphic concept over the basin-margin settings within a Miocene mixed-siliciclastic‑carbonate system","authors":"Ayush Srivastava ,&nbsp;Sudipta Dasgupta ,&nbsp;Mohuli Das ,&nbsp;Pramod Kumar","doi":"10.1016/j.sedgeo.2025.106995","DOIUrl":"10.1016/j.sedgeo.2025.106995","url":null,"abstract":"<div><div>High-frequency sequences characterized by carbonate-dominated TST and HST and siliciclastic-dominated FSST and LST within a mixed-siliciclastic‑carbonate system can be elucidated by the ‘reciprocal sedimentation’ concept. This study integrates lithofacies and ichnofacies analyses, leading to a higher-resolution (4th- to 5th-order) sequence-stratigraphic interpretation, whereby the response of sensitive infaunal niches to these high-frequency base-level changes reciprocates itself ichnologically. The concept of ‘reciprocal bioturbation’, i.e., the ichnological expression of reciprocal sedimentation, offers a novel idea through which the low-order cycles within a mixed siliciclastic–carbonate system can be diagnosed. The bioturbation pattern varies distinctly between the proximal and distal parts of the basin margin. The former records an alternating stacking of the contrasting (A) shallow-marine (e.g., <em>Skolithos</em> Ichnofacies developed in the shoreface deposits) and (B) the continental ichnofacies (e.g., <em>Termitichnus</em> Ichnofacies in the supratidal environments) within the transgressive and the pedogenized regressive intervals, respectively, without showing any gradual transformation in both lithofacies and ichnofacies. This abrupt stacking of reciprocal bioturbation suites reflects omission due to stratigraphically punctuated erosion (e.g., subaerial erosion, regressive marine erosion, and transgressive ravinement) <em>vis-à-vis</em> the scarcity of accommodation in the proximal part of the basin margin. The distal part records gradual and subtle stacking of reciprocal suites, although a convergence can be observed through the reciprocation of normal marine and brackish water (<em>Teichichnus</em> Ichnofacies) assemblages. Hence, identification of ‘<em>reciprocal bioturbation</em>’ serves as the clinching evidence – (a) in delineating the reciprocal sedimentation and (b) in understanding the high-frequency base-level cycles while constructing the low-order sequence-stratigraphic model in a basin-margin setting.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"491 ","pages":"Article 106995"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519229","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":"Dedolomitization-driven karstification and speleogenesis in central Slovenia: Mineralogical and geochemical insights","authors":"Filip Šarc ,&nbsp;Tomasz Powolny ,&nbsp;Andrea Martín-Pérez ,&nbsp;Adrijan Košir ,&nbsp;Beata Gebus-Czupyt ,&nbsp;Andrzej Tyc ,&nbsp;Justyna Ciesielczuk ,&nbsp;Christoph Spötl ,&nbsp;Gabriella Koltai ,&nbsp;Bojan Otoničar","doi":"10.1016/j.sedgeo.2025.106986","DOIUrl":"10.1016/j.sedgeo.2025.106986","url":null,"abstract":"<div><div>This study examines the petrography and geochemistry of dolomite wall rock and associated dedolomite in the Mravljetovo brezno v Gošarjevih rupah cave system of central Slovenia and evaluates the influence of dedolomitization on speleogenesis and karstification. Three distinct dedolomitization-related facies were identified: (i) Type 1, featuring dolomite replaced and cemented by calcite; (ii) Type 2, characterized by bladed and cone-shaped calcite associated with clay minerals and iron oxides; and (iii) Type 3, a detrital, stratified deposit resulting from host rock weathering and allogenic sedimentation and diagenesis in phreatic conditions. Geochemical analyses reveal a progressive loss of Mg and Sr, enrichment in Ca, starting from the unaltered dolomite of the wall rocks up to all facies associated with dedolomitization. In addition, enrichment of Si, Al, Fe and other silicate-associated elements were observed in all dedolomite types. Stable isotope (δ¹³C, δ¹⁸O) data suggest organic carbon input and meteoric diagenesis as primary controlling factors. ΣREE+Y patterns, negative Ce anomalies (Ce/Ce* &lt; 1) and the enrichment in some trace elements (e.g. Zr, Zn, Cu, Pb, Ba) indicate an oxidative environment with a strong detrital influence. Structural discontinuities played a crucial role in directing fluids and detrital material along fault zones and bedding planes which facilitated dedolomitization and subsequently cave formation. The findings show that dedolomitization not only altered the original dolostone fabric but also facilitated speleogenesis by enhancing rock heterogeneity and increasing its susceptibility to dissolution, while at the same time playing an important role in karstification and the further development of dolostone landscape.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"490 ","pages":"Article 106986"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517691","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":"Sedimentary processes of fine-grained sedimentary rocks in lacustrine basins: A case study of the Upper Cretaceous Qingshankou Formation, northern Songliao Basin, China","authors":"NingLiang Sun ,&nbsp;Jinyou Zhang ,&nbsp;Jianhua Zhong ,&nbsp;Jianbo Gao ,&nbsp;Pengpeng Sheng ,&nbsp;Zhiwei Chen ,&nbsp;Zhifeng Cao ,&nbsp;Pingshuai Wang","doi":"10.1016/j.sedgeo.2025.106987","DOIUrl":"10.1016/j.sedgeo.2025.106987","url":null,"abstract":"<div><div>Fine-grained sedimentary rocks (FGSRs) in lacustrine basins are traditionally interpreted as low-energy suspension deposits. However, extensive shale oil exploration has revealed pronounced lithofacies heterogeneity within mudstone successions, necessitating a re-evaluation of their dynamic depositional processes. This study integrates data from eleven cored boreholes, along with petrographic and geochemical analyses, to characterize lithofacies variability, depositional processes, and environmental evolution of the Upper Cretaceous Qingshankou Formation FGSRs in the Songliao Basin. Sedimentological and geochemical proxies indicate that FGSR deposition occurred in brackish-saline waters with moderate stratification and persistent anoxia under warm-humid climatic conditions. A revised depositional framework identifies eight lithofacies and delineates four lacustrine depositional environments that were shaped by intermittent marine incursions: (i) sublittoral proximal deposits, consisting of interlaminated mudstones and siltstones associated with storm-induced tempestites and muddy hyperpycnal flows; (ii) sublittoral distal deposits, dominated by wave-enhanced sediment gravity flows with tripartite microstratigraphy recording turbulent-to-laminar flow transitions; (iii) semi-profundal deposits, comprising hybrid event beds and bottom-current deposits with rhythmically discontinuous silt laminae and mud ripples, the latter formed through bedload transport of clay aggregates under sustained current velocities; (iv) profundal deposits, including laminated varves, organic-rich suspension mudstones, and tuff layers. Their high organic carbon content and minimal bioturbation establish them as important targets for unconventional shale oil exploration. These findings challenge the conventional paradigm of deep-lacustrine quiescence, highlighting the pervasive influence of energetic depositional processes in shaping shale heterogeneity and organic matter preservation. The results have significant implications for the exploration and characterization of lacustrine shale reservoirs on a global scale.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"490 ","pages":"Article 106987"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145420158","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 comparison in hierarchies and architectures between submarine trunk versus tributary canyons and their evolution: A case study from northwestern South China Sea margin","authors":"Dongwei Li ,&nbsp;Chenglin Gong ,&nbsp;Ronald J. Steel ,&nbsp;Yijie Zhu","doi":"10.1016/j.sedgeo.2025.106985","DOIUrl":"10.1016/j.sedgeo.2025.106985","url":null,"abstract":"<div><div>Submarine canyons are important conduits for transporting sediment across continental margins and their canyon heads contribute to further understanding the shelf-to-canyon sedimentary dynamics. Limited attention has been given to describe the internal depositional architectures and their variations from the tributary to trunk canyons in the canyon head regions. High-resolution 3-D seismic data tied to well logs, cores, and grain-size data from the Central Submarine Canyon head developed during late Miocene in Qiongdongnan Basin are utilized to investigate the variation of the hierarchical framework and depositional architectures between tributary and trunk canyons. The results show that canyon head tributaries contain one type of stratigraphic surfaces (i.e., fourth-order erosion surface) and four types of depositional elements (i.e., thalweg sandy debrites, axial high net-to-gross turbidites, off-axial low net-to-gross turbidites, and bank failures). The trunk canyon, in contrast, are characterized by a more complex hierarchical and depositional style, and are distinguished from tributary canyons by the occurrence of internal levees and the fifth-order erosion surface, composed of multiple seismically resolvable incisions. The evolution of the canyon head suggests that tributary canyons at the canyon head erode downstream and converge into the previously developed trunk canyon under the control of paleo-topography, forming a dendritic structure in plan-view. Results from this paper contributes to a better understanding on hierarchical framework and depositional architectures of the submarine canyon head.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"490 ","pages":"Article 106985"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145374527","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":"Sequence stratigraphy of wave-dominated and wave-influenced shoreface deposits: Systems tracts, stratigraphic surfaces and facies contacts","authors":"Massimo Zecchin ,&nbsp;Octavian Catuneanu ,&nbsp;Mauro Caffau","doi":"10.1016/j.sedgeo.2025.106980","DOIUrl":"10.1016/j.sedgeo.2025.106980","url":null,"abstract":"<div><div>Shoreface deposits are usually associated with high-energy sedimentary structures, as well as with erosional surfaces produced by waves and currents that may have sequence stratigraphic or sedimentological significance. Typical sequence stratigraphic surfaces associated with shoreface deposits are the ravinement surface (RS), the maximum flooding surface (MFS), the basal surface of forced regression (BSFR), the regressive surface of marine erosion (RSME), the subaerial unconformity (SU) and the correlative conformity (CC). However, some of these surfaces, such as the MFS, the BSFR and the CC can be cryptic and difficult to pinpoint in outcrops and cores. Facies contacts in the shoreface are represented by the local flooding surface (LFS), the downlap surface (DLS), the surf diastem (SD) and bedset boundaries (BB), which are usually well recognizable. All downstream-controlled systems tracts may form in shoreface deposits, including the lowstand systems tract (LST), transgressive systems tract (TST), highstand systems tract (HST) and falling-stage systems tract (FSST). Among these systems tracts, TSTs and HSTs are most commonly recognized. A challenge in these settings is the distinction between HSTs, FSSTs and LSTs, due to the more subtle physical expression of the BSFR and the CC in fully shoreface successions. Sequence stratigraphic surfaces and facies contacts can be identified on the basis of several criteria, including sedimentological, ichnological, diagenetic, mineralogic, geophysical, and micropaleontological. Due to their easy recognition with all kinds of data, RSs are commonly chosen as boundaries of stratigraphic sequences composed of shoreface or mixed shoreface-shelf deposits, commonly referred to as transgressive-regressive (T-R) sequences.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106980"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160146","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":"Detrital zircon U–Pb ages and provenance of Permian sandstones from Sado Island, central Japan: Implications for Rodinia-derived sources in the eastern Central Asian Orogenic Belt","authors":"Keisuke Suzuki ,&nbsp;Toshiyuki Kurihara ,&nbsp;Hirotaka Ishida ,&nbsp;Toshiro Takahashi ,&nbsp;Hayato Ueda","doi":"10.1016/j.sedgeo.2025.106983","DOIUrl":"10.1016/j.sedgeo.2025.106983","url":null,"abstract":"<div><div>To better understand the sedimentation, tectonics, and paleogeographic evolution of Northeast Asia, we present new integrated data including sandstone petrography, whole-rock geochemistry, and detrital zircon U–Pb ages for Permian strata of Sado Island in the Sea of Japan. The sandstones are rich in quartz and feldspar and are classified as feldspathic arenite and wacke. They exhibit high SiO₂, La, Th, and Zr contents, and light rare earth element enrichment with flat heavy rare earth patterns, indicating an island arc provenance with granitic basement exposure. Trace element enrichments (e.g., V, Cr, and Ni) suggest the partial presence of exposed mafic igneous rocks on the arc surface. Detrital zircon U–Pb ages show middle–late Permian (270–256 Ma) peaks, along with late Mesoproterozoic to middle Neoproterozoic (1022–762 Ma) and middle Cambrian to Early Devonian (507–403 Ma) populations. The Mesoproterozoic–Neoproterozoic zircons originated from the Songliao–Xilinhot and Jiamusi–Khanka blocks in the eastern Central Asian Orogenic Belt, associated with peripheral orogenies of the supercontinent Rodinia. The Cambrian zircons (540–510 Ma) with low Th/U ratios (&lt;0.44) likely reflect detritus contributions from granite and amphibolite- to granulite-facies metamorphic rocks associated with the Mashan Complex of the Jiamusi–Khanka Block. Double-sided subduction zones between the North China Craton and the Songliao–Xilinhot and Jiamusi–Khanka blocks may have provided a tectonic linkage between Sado Island, Rodinia-derived source regions, and complex arc–trench systems at the junction of the Paleo-Asian–Mudanjiang and Paleo-Pacific oceans during the middle–late Permian.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106983"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321502","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":"Reconstructing the palaeoenvironment of a deep onshore basin of the Late Miocene Mediterranean salt giant (Belice basin, Italy): Insights from hemipelagic deposits interbedded with clastic evaporites","authors":"Enrico Nallino ,&nbsp;Francesco Dela Pierre ,&nbsp;Nicolò Zanellato ,&nbsp;Luca Pellegrino ,&nbsp;Daniel Birgel ,&nbsp;Irene Cornacchia ,&nbsp;Andrea Cotellucci ,&nbsp;Marcello Natalicchio","doi":"10.1016/j.sedgeo.2025.106960","DOIUrl":"10.1016/j.sedgeo.2025.106960","url":null,"abstract":"<div><div>Large and deep marine evaporitic basins (salt giants) are common in the geological record, but the reconstruction of the palaeoenvironment is challenging. The sedimentary products consist of clastic evaporites (mass transport and turbiditic deposits), commonly interbedded with evaporitic cumulates or non-evaporitic fine-grained deposits representing the background hemipelagic sedimentation. The study of the hemipelagic component can provide crucial palaeoenvironmental information on these basins. This study examines the non-evaporitic, hemipelagic sediments interbedded with gypsum turbidites from the Belice Basin (Italy), a deep onshore basin of the Late Miocene Mediterranean salt giant. The studied succession belongs to the Resedimented Lower Gypsum unit, formed during the second phase of the Messinian Salinity Crisis (5.60–5.55 Ma) and consists of laminated diatomaceous and organic-rich shales, dolomitic and aragonitic mudstones. Sedimentological, petrographic, and geochemical analyses indicate that the hemipelagites accumulated in a rather deep basin, with high primary productivity in superficial waters. The palaeoenvironmental conditions in the water column and at the seafloor were governed by the balance between the inflows of freshwater and marine water. Intervals of reduced continental runoff and enhanced marine ingression, which induced water column mixing and seafloor oxygenation, are recorded by the diatomaceous shales. The other lithologies record prolonged stratification of the water column, induced by riverine runoff and basin restriction. Seafloor anoxia and the input of terrestrial and marine organic matter favoured the formation of dolomite and pyrite following bacterial sulphate reduction. This study provides insights into the chemical, physical, and biological conditions in a deep basin during the Messinian Salinity Crisis.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106960"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097825","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":"Redox stratification and ecological implications of microbial dolomites in the late Ediacaran Dengying Formation, Yangtze platform","authors":"Zhibo Yang ,&nbsp;Hancheng Ji ,&nbsp;Yanqing Shi ,&nbsp;Ting Liang ,&nbsp;Zhidong Bao","doi":"10.1016/j.sedgeo.2025.106961","DOIUrl":"10.1016/j.sedgeo.2025.106961","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The late Ediacaran ocean witnessed a critical phase in the evolution of early life, during which redox conditions were closely linked to biological innovation. Nevertheless, the nature of these redox conditions and their interactions with evolving ecosystems remain debated. This study provides a systematic investigation of the petrographic and geochemical characteristics of microbial dolostones from the Dengying Formation on the Yangtze Platform, South China. The results reveal that microbial dolomites in this unit comprise a diverse suite of lithofacies—bioclastic, stromatolitic, oncoidal, foam-spongy, and thrombolitic dolomites—indicative of intertidal to subtidal depositional settings. Microbialite components are classified into microbial matrix, fibrous dolomite cements, and clear equant dolomite cements. Among these, Fibrous dolomite is particularly well-developed, and its cathodoluminescence zoning and length-slow optical properties suggest &lt;em&gt;syn&lt;/em&gt;-depositional precipitation during early diagenesis. Combined δ&lt;sup&gt;13&lt;/sup&gt;C and &lt;sup&gt;87&lt;/sup&gt;Sr/&lt;sup&gt;86&lt;/sup&gt;Sr data suggest a warm and humid climate with high primary productivity and intense continental weathering during the Z&lt;sub&gt;2&lt;/sub&gt;dn&lt;sup&gt;2&lt;/sup&gt; interval, followed by a decline in sedimentation rates during Z&lt;sub&gt;2&lt;/sub&gt;dn&lt;sup&gt;4&lt;/sup&gt;, albeit with continued robust carbonate deposition. All dolomite components exhibit distinct negative cerium anomalies (Ce/Ce* &lt; 1), heavy rare earth elements (HREEs) enrichment, and elevated Y/Ho ratios, collectively indicating deposition under well‑oxygenated shallow marine conditions. Notably, the fibrous dolomite component displays the most pronounced oxidative signature, with oxygen levels at the sediment–water interface potentially approaching atmospheric values. In contrast, the clear equant dolomite cements components reflect suboxic to weakly oxic conditions, suggesting a stratified redox water column during the late Ediacaran. These observations imply that localized oxygen-rich zones on the seafloor may have developed through microbial oxygen production. When compared across the entire Ediacaran, the widespread microbial dolomites of the Dengying Formation and their associated oxic conditions likely provided key ecological niches for early benthic metazoans, such as bilaterians. The oxygenation process recorded in this formation may have played an important role in setting the stage for the Cambrian Explosion. The Dengying Formation thus captures a significant shallow-marine oxygenation event closely associated with algal proliferation and the emergence of multicellular life, underscoring the role of biologically mediated environmental feedbacks during the terminal Neoproterozoic. This study enhances our understanding of the interplay between seawater redox structure and microbial activity at the close of the Ediacaran, and supports the interpretation that microbial metabolism may have been a key regulatory mechanism in the devel","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106961"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057215","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":"Multi-episodic bauxitization in a karstic and rifted setting (Early Cretaceous, South-western Iberian Basin, Spain): An interdisciplinary approach","authors":"Elisa Laita ,&nbsp;Alejandro Lorenzo ,&nbsp;Raúl De La Horra ,&nbsp;María Belén Muñoz-García ,&nbsp;Alfonso Yuste ,&nbsp;Blanca Bauluz ,&nbsp;Marian Fregenal-Martínez","doi":"10.1016/j.sedgeo.2025.106981","DOIUrl":"10.1016/j.sedgeo.2025.106981","url":null,"abstract":"<div><div>Bauxitic deposits serve as valuable sedimentary archives, offering insights into paleoclimatic, paleogeographic, and geodynamic processes over time. A multidisciplinary analysis of bauxitic deposits in the Cuenca Domain (Iberian Ranges, central Spain) aims to reconstruct their genesis in the framework of the geological evolution of this region during the Late Jurassic-Early Cretaceous rift episode. The bauxitic deposits preserve paleosol profiles that show multi-episodic processes of sedimentation, reworking, erosion, pedogenesis, and bauxitization, reflecting a landscape's dynamics that was strongly influenced by episodic tectonic activity. The presence of book-type kaolinite aggregates, ferruginous pisoids and ooids, and soil horizons provide evidence of <em>in situ</em> bauxitization. On the other hand, the presence of fractured pisoids and ooids, brecciated textures, and bauxitic C horizons also points to some degree of reworking. Authigenic boehmite suggests optimal conditions for bauxitization, whereas ferruginous crusts and peds at the top of the deposits point to a later ferruginization phase. A subsequent kaolinitization episode, probably driven by the infiltration of silica-rich fluids, is also recorded. By integrating stratigraphic, sedimentological, and mineralogical data, a succession of genetic stages in bauxite development has been identified, shaped by the tectonic evolution of the area. The proposed stratigraphic and pedogenetic model enhances the regional significance of the findings and enables a refined chronology of its tectonic evolution. The results highlight the potential of bauxitic materials, not only as paleoclimatic indicators but also as robust tools for reconstructing paleogeographic and tectonic conditions in complex settings where the sedimentary record is apparently homogeneous and extremely incomplete.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106981"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321501","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":"Principal component analysis reveals the relationship between carbonate facies, geochemical properties, and diagenetic overprint","authors":"Arman Jafarian ,&nbsp;Antun Husinec ,&nbsp;Rute Coimbra ,&nbsp;Adrian Immenhauser ,&nbsp;Umid Kakemem ,&nbsp;Clemens V. Ullmann ,&nbsp;Meng Wang ,&nbsp;Abdus Saboor ,&nbsp;Chengshan Wang","doi":"10.1016/j.sedgeo.2025.106979","DOIUrl":"10.1016/j.sedgeo.2025.106979","url":null,"abstract":"<div><div>Marine carbonate archives in transitional coastal-to-basin settings are susceptible to syn- and post-depositional alteration, a feature that complicates the interpretation of primary environmental signals encoded in the sedimentary archive at the time of deposition. This study utilises Principal Component Analysis (PCA) to elucidate the intricate relationships between facies types, environmental controls, and the sediments' respective diagenetic susceptibilities to geochemical resetting within lower Aptian carbonates of the Kazhdumi Intrashelf Basin (Zagros Basin, Iran). The focus is on proximal mid-ramp to intrashelf-basin carbonates. Integrating facies analysis, petrography, geochemistry, and PCA, the following outcomes result: (i) Proximal facies exhibit higher Mn/Ca and lower Sr/Ca ratios linked to enhanced fluid-rock interactions and terrigenous input. Marine δ¹³C values and elevated Sr/Ca ratios are more pronounced in distal facies. (ii) Bulk isotope values from distal carbonates are characterised by enriched δ¹³C and depleted δ¹⁸O values. This suggests increased marine productivity in cooler waters and intermittently anoxic-suboxic conditions. (iii) In shallower, warmer, and well‑oxygenated proximal mid-ramp waters, reduced organic carbon burial, isotopically light carbon from terrestrial sources and the oxidation of organic matter result in lowered δ¹³C and higher δ¹⁸O values. The study demonstrates that despite complex diagenetic overprint, marine proxy signals remain discernible. Supported by microfacies data, PCA reveals a multi-faceted system that drives geochemical variability within a facies/bathymetric context. This outcome emphasises the critical importance of detailed facies analysis and geochemical profiling in reconstructing palaeoenvironmental conditions.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"489 ","pages":"Article 106979"},"PeriodicalIF":2.9,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221751","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}