Journal of Palaeogeography最新文献

{"title":"The role of algal reproduction in phylloid algal buildups: a case study in Pennsylvanian phylloid algae in southern Guizhou, China","authors":"Jun-Jie Wang ,&nbsp;En-Pu Gong ,&nbsp;Yong-Li Zhang ,&nbsp;Wen-Tao Huang ,&nbsp;Xiao Li ,&nbsp;Li-Fu Wang ,&nbsp;Guan-Ming Lai ,&nbsp;De-Peng Li","doi":"10.1016/j.jop.2025.02.002","DOIUrl":"10.1016/j.jop.2025.02.002","url":null,"abstract":"<div><div>The well-preserved reproductive morphology of <em>Eugonophyllum</em> within Pennsylvanian algal deposits in Guizhou Province, South China, provides a unique opportunity to study phylloid algal ecology and its role in carbonate buildups. Vegetative reproduction, characterized by the branching growth of algal segments followed by lateral budding in young thalli, appears to be the primary mechanism for maintaining and continuously increasing the population in the community. This method provides a dense, stable framework and bioclastic sediments for the development of lateral growth. Sexual reproduction occurs among mature thalli (comprising approximately 5%–10% of the population) and is characterized by synchronous gamete release. The synchronous spawning periodically increases the population and controls reef growth by the superposition of alternating generations. The combined effects of intrinsic factors of phylloid algae (rapid growth and reproductive strategy) and extrinsic factors (nutrient availability, ocean chemistry, seawater temperature) contributed to the dominance of phylloid algae in reef ecosystems in tropical-subtropical regions during the Pennsylvanian. Detailed evidence of <em>Eugonophyllum</em> growth and reproduction reveals the widespread distribution and high productivity of phylloid algae, opening new insights into global algal reef ecosystem blooms.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 664-678"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Pleistocene vertebrate tracks impressed on Oligocene beds from the southernmost Iberian Peninsula: Palaeogeographic implications","authors":"Eduardo Mayoral ,&nbsp;Antonio Rodríguez Ramírez ,&nbsp;Jérémy Duveau ,&nbsp;Ricardo Díaz-Delgado ,&nbsp;Juan Antonio Morales ,&nbsp;Eloísa Bernáldez Sánchez ,&nbsp;Esteban García-Viñas ,&nbsp;Ana Santos ,&nbsp;Mili Jiménez Melero ,&nbsp;Milagros Alzaga ,&nbsp;Ignacio Díaz-Martínez","doi":"10.1016/j.jop.2025.01.004","DOIUrl":"10.1016/j.jop.2025.01.004","url":null,"abstract":"<div><div>The southern of the Iberian Peninsula preserves a diverse ichnological record of vertebrates from the late Neogene–Quaternary. While the ages of several tracksites, such as those from the Miocene–Pliocene transition and the middle-late Pleistocene, are well-established, others remain undated or have unknown ages. This paper reports the discovery of the southernmost tracksite in the Iberian Peninsula and continental Europe on the Island of Tarifa (Cádiz). The tracksite contains over 600 vertebrate footprints from the early Pleistocene that are grouped in four morphotypes. Morphotypes 1, 2 and 3 (M1, M2 and M3) are predominantly didactyl-shaped, rounded to ovoid and elongated, and associated with tracks left by artiodactyls. Morphotype 4 (M4), suboval to subcircular in outline, is the largest and is probably related to the imprint left by proboscideans.</div><div>We also document the progressive transition from morphotype 2 with isolated, rounded footprints to morphotype 3 with elongated tracks formed by overlapping two tracks of the same animal which is observed. The consistency of the substrate, together with the trackmaker limb dynamics, conditioned the final morphology of the tracks, which were produced in a very soft clay-rich substrate of late Oligocene, that was folded and tilted in the latest Pliocene. This relief configuration gave rise to a narrow, partially or totally flooded corridor through which the trackmaker animals passed continuously, simultaneously, and in opposite ways. This discovery from the southernmost tip of continental Europe is the first one from the early Pleistocene in the Iberian Peninsula and a rare example from the Mediterranean region.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 315-333"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two ribbon-like macrofossils in contrasting preservational styles from the Ediacaran–Cambrian interval","authors":"Yu-Lan Li ,&nbsp;Giovanni Mussini ,&nbsp;Li-Jun Zhang ,&nbsp;Si-Cun Song ,&nbsp;Ming Li ,&nbsp;Ling Zhong ,&nbsp;Feng Tang","doi":"10.1016/j.jop.2025.03.002","DOIUrl":"10.1016/j.jop.2025.03.002","url":null,"abstract":"<div><div>The fossil record of the latest Ediacaran and earliest Cambrian comprises diverse tubular and ribbon-like macrofossils of uncertain affinities, some of which could record early metazoans and macroalgae. This study compares two ribbon-like macrofossils typical of Ediacaran–Cambrian intervals, investigating their morphology, potential affinities, and biostratigraphic significance: <em>Rugosusivitta</em>, preserved as essentially two-dimensional carbonaceous compressions, and <em>Harlaniella,</em> preserved as casts and molds. It is shown that the recently described <em>Rugosusivitta orthogonia</em> Tang et al., 2021 resembles the tube-like <em>Harlaniella ingriana</em> in its morphology, characterized by a combination of transverse ridges and longitudinal stripes separated into distinct parts of an elongate body. This combination of features challenges algal or protistan affinities, leaving open the possibility of metazoan origins. Both <em>Rugosusivitta</em> and <em>Harlaniella</em> likely represent body fossils rather than ichnofossils consistent with their preservation as either carbonaceous compressions or sediment-infilled tubes, respectively. By reconstructing the global distribution of <em>Rugosusivitta</em> and <em>Harlaniella</em> in different taphonomic windows, we suggest that these fossils record a coherent morphotype spanning the Ediacaran–Cambrian boundary.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 651-663"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palaeogeomorphological control on the depositional architecture of lacustrine gravity-flow deposits in a depression lacustrine basin: a case study of the Triassic Yanchang Formation, southern Ordos Basin, China","authors":"Ming-Cheng Liu ,&nbsp;Sheng-He Wu ,&nbsp;Da-Li Yue ,&nbsp;Zhen-Hua Xu ,&nbsp;Xiao-Long Wan ,&nbsp;Hong-Li Wu ,&nbsp;Zhao-Hui Chen ,&nbsp;Zhen Li","doi":"10.1016/j.jop.2025.01.003","DOIUrl":"10.1016/j.jop.2025.01.003","url":null,"abstract":"<div><div>Lacustrine gravity-flow deposits have enormous hydrocarbon potential. However, their depositional architecture has long been considered very complicated and is controlled by various factors, making petroleum exploration and development highly challenging. The influence of palaeogeomorphology on the extent and formation mechanisms of lacustrine gravity-flow deposits remains poorly understood. This study uses 3D seismic data, well-log data, and core data to characterize the palaeogeomorphology and depositional architecture of the lacustrine gravity-flow deposit of the Yanchang Formation in the Ordos Basin, while analyzing the influence of palaeogeomorphology on the architecture, distribution, and evolution of lacustrine gravity-flow deposit systems. The results showed that three palaeogeomorphologic units—shelf, slope, and basin floor—developed in the basin. Gravity-flow deposits can be further divided into channel and lobe systems. Gravity-flow channel systems have developed in the upper slope area, which include three types of architectural elements: confined channels, unconfined channels, and levee-overbank. As the transport distance of gravity flow increases, the erosion ability of gravity flow weakens, resulting in the terrain formed by gravity flow erosion gradually weakening the constraint on sediment transport. Consequently, gravity-driven flow pathways shift from linear, confined channels to curved, unconfined channels, finally leading to the development of numerous distributary channels. In the lower slope area, gravity flow sediments distribute rapidly and accumulate to form lobes after encountering slope breaks, due to the decrease of dynamics, including three types of architectural elements: distributary channels, lobe axis and lobe fringe. These lobes are tongue-shaped and fan-shaped on the plane. A series of lobes are superimposed and form a lobe complex set. These lobe complex sets are distributed in a branch-like manner. There are many branch-shaped low-bend amplitude channels inside the lobe complex set. Palaeogeomorphology plays an important role in controlling the spatial distribution of depositional architecture. As the slope gradient increases, the influence of slope break on sediment gravity flow weakens, leading to a delay of the sediment gravity flow slumping to the basin bottom. Additionally, the extension length of the channel system on the slope increases. Furthermore, the extension length of the lobes toward the center of the basin also increases. This work improves the fundamental understanding of the depositional architecture of lacustrine gravity-flow deposits and may help enhance sand prediction for the same type deposit reservoirs.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 476-500"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclostratigraphy of the Middle Jurassic Aalenian Sha-1 member lacustrine record in central Sichuan Basin, southwestern China","authors":"Xiao-Fei Feng ,&nbsp;Xiao-Ming Zhao ,&nbsp;Massine Bouchakour ,&nbsp;Xi Zhang ,&nbsp;Jia-Wang Ge ,&nbsp;Yue-Li Liang ,&nbsp;Chang-Cheng Yang","doi":"10.1016/j.jop.2025.03.001","DOIUrl":"10.1016/j.jop.2025.03.001","url":null,"abstract":"<div><div>Cyclostratigraphic studies enable to reconstruct the geological timescales of many marine formations. However, these investigations are still lacking a precise astronomical tuning in lacustrine environments, particularly in the Middle Jurassic, due to the paucity of biological traces and the lack of data. In this study, detailed spectral analyses of natural gamma ray (GR) logging data were conducted on the lacustrine Sha-1 member from two wells in the Sichuan Basin, southwestern China. Core data samples were calibrated to test the lithological changes for proceeding with cyclostratigraphic analysis with more confidence. The spectral analysis and evolutionary spectral analysis of the GR logs reveal that the wavelength ratios of the stratigraphic cycles are ∼20:5:2:1, being consistent with the period ratios of astronomical cycles (long eccentricity, short eccentricity, obliquity, and precession). Correlation coefficient (COCO) analyses were applied to quantitatively measure the fitting of the witnessed sedimentary cycles to astronomical periods and provide a possible sedimentation rate range. The results show that astronomical time scale of the studied interval comprises 58.4–60.6 m cycles, representing the 405 kyr eccentricity cycles, and 14.9–16.6 m cycles, representing the ∼100 kyr eccentricity cycles. This study reveals a ∼2.43 Myr duration for the Sha-1 member. Sedimentary noise modeling reveals that long-term million-year period (1.2 Myr) astronomical forcing may have been a significant driver of lake-level changes in the Sichuan Basin. Moreover, high-frequency (405 kyr scale) lake-level variations associated with the mid-term base-level cycles (4th-order sequences) were linked to climato-eustatic changes. This study suggests comparison between parameters of cyclostratigraphic records and sequence stratigraphic base-level cycles in lacustrine sediments. The stratigraphic surfaces of mid-term base-level cycles correspond to minima ∼405 kyr-long eccentricity cycle curve and high values of DYNOT (dynamic noise after orbital tuning). Integrating cyclostratigraphy with the base-level cycles is, therefore, a vital approach for defining the short-term oscillations of lake-level, and proved to be a useful tool for characterizing thin-bedded lacustrine reservoirs.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 452-475"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New species of larger benthic foraminifera from the Maastrichtian deposits of the southern margin of the Neotethys (Zagros Foreland Basin)","authors":"Hossein Ghanbarloo ,&nbsp;Amrollah Safari ,&nbsp;Muhittin Görmüş","doi":"10.1016/j.jop.2024.10.003","DOIUrl":"10.1016/j.jop.2024.10.003","url":null,"abstract":"<div><div>The investigation mainly focuses on larger benthic foraminifera, <em>Canalispina</em>, <em>Siderolites</em>, <em>Loftusia</em>, and <em>Omphalocyclus</em> from the Maastrichtian deposits (Tarbur Formation) in the Zagros Foreland Basin. The four new species: <em>Canalispina zagrosia</em> sp. nov., <em>Siderolites persica</em> sp. nov., <em>Loftusia tarburica</em> sp. nov., and <em>Omphalocyclus tarburensis</em> sp. nov., and four other index species: <em>Siderolites calcitrapoides</em>, <em>Omphalocyclus cideensis</em>, <em>O. macroporus</em>, and <em>Loftusia baykali</em> were identified. <em>L. harrisoni</em> is thought to be ancestor of <em>L. minor</em>, <em>L. arabica</em>, <em>L. matsumarui</em>, <em>L. tarburica</em> sp. nov., <em>L. occidentalis</em>, <em>L. coxi</em>, <em>L. baykali</em>, <em>L. kahtaensis</em> and <em>L. oktayi</em> during the early, middle and late Maastrichtian, while <em>L. persica</em> and <em>L. elongata</em> evolved into <em>L. arabica</em> in the middle Maastrichtian. <em>L. turcica</em> and <em>L. morgani</em> are close forms of <em>L. elongata</em> in the middle and late Maastrichtian, and <em>L. anatolica</em> and <em>L. morgani</em> are the predominant forms in the late Maastrichtian. The wall structures of <em>Loftusia</em> species are more complex in the late Maastrichtian than in early Maastrichtian forms due to evolutionary trends. <em>Loftusia</em> species with numerous whorls were predominant in the middle Maastrichtian. In contrast to this, the species with low whorl numbers during the early and late Maastrichtian were dominant. Detailed studies on <em>Omphalocyclus</em> species indicate that (1) the genus <em>Omphalocyclus</em> migrated from the middle part of the Tethys to other Tethyan areas during the late Campanian, and (2) the diversity of <em>Omphalocyclus</em> species of eastern Tethys (North African part) was higher than in other areas.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 535-558"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dinoflagellate cyst and nannofossil imprints in the middle Eocene Kirthar transgressive strata from the western Garo Hills, South Shillong Plateau, India","authors":"Ashish Kumar Mishra ,&nbsp;Prem Raj Uddandam ,&nbsp;Stuti Saxena ,&nbsp;Abha Singh","doi":"10.1016/j.jop.2025.01.005","DOIUrl":"10.1016/j.jop.2025.01.005","url":null,"abstract":"<div><div>One of the global characteristic features of the Eocene is the extensive development of carbonate platforms in various regions of Tethys. Paleogene sequences of the Shillong Plateau from west to east are exposed in the steep Garo, Khasi and Jaintia hills. In the Khasi and Jaintia hills, Paleogene successions are represented by alternating carbonates and siliciclastics and provide datable micropaleontological fossils, whereas in the Garo Hills, which is in the south-western part of the Shillong Plateau, the Paleogene succession is mainly represented by siliciclastics and fewer carbonates. As the carbonates in this area are mostly marly, the recovery of carbonate microfossils is difficult. Accurate age assignment is important to correlate the sedimentary successions of the Khasi, Jaintia and Garo hills, which are mostly time transgressive and different lithologies were deposited at the same time. A detailed palynological investigation of 65 samples from the 25-m-thick sedimentary succession of the Siju Formation, Western Garo Hills, has yielded well-preserved and diverse organic-walled dinoflagellate cysts and calcareous nannofossils. Dinoflagellate cysts (<em>Heteraulacacysta porosa, H. leptalea</em>) and nannofossils (<em>Discoaster barbadiensis</em>, <em>D. saipanensis</em>, <em>Reticulofenestra bisecta</em>, <em>R. erbae</em>, and <em>R. reticulata</em>) indicate a middle Eocene age (Bartonian) for the studied section. The synthesis of nannofossils and dinocysts with records from India and Australia reveals a major late Bartonian transgression in the Indo-Pacific known as the ‘Kirthar transgression’.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 559-578"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin and evolution of large-scale sublacustrine fans in a lacustrine rift basin: a case study from the Liaozhong Depression (Bohai Bay Basin, E China)","authors":"Bang-Ning Xu,&nbsp;Hao Liu,&nbsp;Jie Xu","doi":"10.1016/j.jop.2025.02.001","DOIUrl":"10.1016/j.jop.2025.02.001","url":null,"abstract":"<div><div>Large-scale sublacustrine fans developed in lacustrine rift basins in China received extensive attention due to their significant implications in both sedimentological studies and petroleum exploration. Taking Member 3 of the Dongying Formation in the central-southern Liaozhong Depression, Liaodong Bay, Bohai Bay Basin as a case study, we conducted a systematic investigation into the depositional characteristics, sedimentary processes, and controlling factors governing the development of large-scale lacustrine fans through integrated analysis of seismic profiles, core samples, and well logging data. The research results indicated that three braid deltas developed in the transgressive systems tract of Member 3 of the Dongying Formation in the western slope belt of the study area. In contrast, the large-scale sublacustrine fan developed in the lake basin environment on the east side of the braid delta system. The sublacustrine fan is primarily composed of grey sandstone and mudstone, with deformed structures and coarse debris. Based on sedimentary characteristics, it can be categorized into two main types: turbidity currents and sandy debris flows. The development of large-scale sublacustrine fans is primarily influenced by four key factors: tectonic activity, paleogeomorphology, sediment supply, and lake-level fluctuations. During the deposition of the Dongying Formation, strike-slip and extension processes created multiple uplifts and depressions in the Liaodong Bay, including the Liaoxi Depression, the Liaoxi Uplift, and the Liaozhong Depression. The Liaoxi Uplift and the Yanshan Fold Belt to the west of the Liaodong Bay are the main sediment sources for the formation of multiple braid deltas on the western slope of the Liaozhong Depression, which in turn provided sediments for the sublacustrine fans. In addition, the sedimentary slope break located between the delta front and the prodelta controls the development and distribution of sublacustrine fans. The rising lake-level during the transgressive systems tract led to frequent fluctuations in water levels, establishing optimal water depth and hydrodynamic conditions conducive to the development of sublacustrine fans. The sublacustrine fan in the lacustrine rift basin was influenced by various factors, with multiple provenance supplies being one of the crucial factors for the development of large-scale sublacustrine fans. This favorable geological setting provided optimal conditions for the development of high-quality reservoirs and facilitated the exploration of substantial hydrocarbon accumulation. This research will serve as a reference for other similar lake basins worldwide.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 431-451"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated sedimentological, ichnological, taphonomic, and low-order sequence-stratigraphic insights into the Oligocene shoal deposits: The Coral Limestone Member, Kutch Basin, India","authors":"Kanchan Prasad,&nbsp;Sudipta Dasgupta,&nbsp;Renzo D'souza","doi":"10.1016/j.jop.2024.11.006","DOIUrl":"10.1016/j.jop.2024.11.006","url":null,"abstract":"<div><div>Integrating the ichnologic, taphonomic, and sedimentologic data enhances the accuracy of palaeoenvironmental interpretations. The integrated analysis of the Chattian-age Coral Limestone Member within the Maniyara Fort Formation in Kutch Basin focuses on understanding the palaeogeographic architecture of microfacies association and the influencing factors determining the same on a typical Late Oligocene carbonate ramp. Through distinct petrographic examination, six distinct microfacies representing outer ramp (MF1 and MF2), middle ramp (MF3, MF4, and MF5), and inner ramp (MF6) depositional settings were identified. The Member, characterised primarily by multiple carbonate coquina intervals, was further classified based on taphonomical and ichnological characteristics. Four taphofacies (TF1, TF2, TF3, and TF4) and five ichnofabrics were identified. The outer ramp exhibits massive-appearing intensely to completely bioturbated (BI 5–6) marly mudstone–wackestone lithofacies with erosional contacts. The middle ramp displays oligotrophic conditions characterised by swaley cross-stratified bioclastic packstone–rudstone beds showing an upward intensifying moderate to intense bioturbation (BI 3–5). The storm-influenced inner ramp features the crudely swaley cross-stratified rudstone shell beds and patchy coral reefs with intense bioturbation (BI 5). Intermittent non-depositional and bioerosional short-duration episodes were observed at the top of skeletal concentrations. The integrated findings mentioned above exhibit coherence and offer valuable insights into the development of carbonate ramps. Our study offers insight into the aggrading and prograding shoal deposits within the carbonate ramp settings of a Chattian tropical sea. It highlights the complex interaction of environmental factors during this period within a high-resolution sequence-stratigraphic framework, extending up to the 5th-order, reported for the first time. This study deepens our comprehension of Oligocene carbonate buildups on a global scale — a research that has received lesser recognition compared to Eocene or Miocene carbonates.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 579-602"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giant paleo-landslides in the upper reaches of the Yellow River: Spatio–temporal distribution, and possible controlling factors","authors":"Yi-Qi Ji ,&nbsp;Sheng-Rui Su ,&nbsp;Alessandro Simoni ,&nbsp;Qiang-Bing Huang","doi":"10.1016/j.jop.2024.12.006","DOIUrl":"10.1016/j.jop.2024.12.006","url":null,"abstract":"<div><div>A large number of giant paleo-landslides were found in the section from Lagan Gorge to Liujia Gorge, which is located in the upper reaches of the Yellow River. This area is located in the transition zone between the Qinghai–Tibet Plateau and the Loess Plateau with a semi-arid climate. The occurrence of lacustrine deposits suggests that some of the giant landslides ever blocked the river and landslide-dammed lakes have occurred in this area. The chronology of the giant landslide in the upper Yellow River was obtained and analyzed by optically stimulated luminescence (OSL) dating and established a chronological framework combining previous data. From the perspective of space, there are five major landslide clusters in the upper Yellow River. They are mainly located in the canyons at the junction of the Yellow River valley, and the center of every basins, which are inextricably linked to the unique sedimentary and tectonic environments of each basin. From the perspective of time, giant landslides also tend to occur during interglacial or glacial-to-interglacial transitions. Paleoseismicity and precipitation appear to be coupled and have competing relationships in their contribution to the formation of giant landslides.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 2","pages":"Pages 391-412"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}