Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Dietary change across the Paleocene-Eocene Thermal Maximum in the mesonychid Dissacus praenuntius","authors":"Andrew Schwartz ,&nbsp;Larisa R.G. DeSantis ,&nbsp;Rob S. Scott","doi":"10.1016/j.palaeo.2025.113089","DOIUrl":"10.1016/j.palaeo.2025.113089","url":null,"abstract":"<div><div>The effect of climate change and ecological disruption on species diets is critical for understanding the evolution of mammalian adaptations and potential risks from the current climate crisis. Here, we use dental microwear texture analysis (DMTA), a likely correlate of the mechanical properties of masticated food, to infer changes in diet within the mesonychid <em>Dissacus praenuntius</em> across the Paleocene-Eocene Thermal Maximum (PETM), a period of geological rapid warming and aridification ∼56 million years ago. Our results clarify previous reconstructions of this species as a small vertebrate mesocarnivore by emphasizing a durophagous dietary component. By comparing dental microwear across the PETM, we conclude that <em>Dissacus praenuntius</em> consumed less flesh and more bone during and after the PETM in comparison to before the event. Coupled with body mass reduction, dietary change during the PETM supports reduced primary and secondary productivity, rather than increased temperatures directly as a major probable cause of body mass reduction. We show that climate and ecological changes during the PETM caused dietary shifts in a species of flesh-eating mesonychid. These results reveal the ecology of the first large mammal predators as well as how mammalian diet may respond to modern climatic and habitat disruption.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113089"},"PeriodicalIF":2.6,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298986","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":"Intense tropical cyclone activity over the past 2000 years at Bay of Islands, Fiji","authors":"Yanan Li ,&nbsp;Jeffrey P. Donnelly ,&nbsp;Nicole d'Entremont ,&nbsp;James F. Bramante ,&nbsp;Krishna K. Kotra ,&nbsp;Shu Gao","doi":"10.1016/j.palaeo.2025.113090","DOIUrl":"10.1016/j.palaeo.2025.113090","url":null,"abstract":"<div><div>Tropical cyclones (TCs) are among the most devastating hazards, causing damage and fatalities in coastal communities. Our understanding of the climatic factors that modulate tropical cyclone activity is impeded by the short historical records and the scarcity of paleoclimatic reconstructions, with a notable dearth of data in the Southern Pacific region. In this paper, we present a sedimentary record from a coastal karst basin in Bay of Islands, Vanua Balavu, Fiji to provide insight into the regional intense TC activity over the past two millennia. A total of 53 intense storm events captured by this site are identified using coarse fraction (&gt;63 μm) anomalies in sediment core retrieved from the basin, yielding an overall average event frequency of 2.6 events/century. Multiple centennial-scale quiescent periods (from 200 to 300 CE and 1000 to 1150 CE) and active periods (namely from 350 to 750 CE, 900 to 1000 CE, 1150 to 1250 CE, 1400 to 1500 CE, and 1650 to 2017 CE) are found in the reconstruction, and the most active interval spans from 1650 to 1800 CE at 4.5 events/century.</div><div>A comparison between existing paleostorm records and climate forcing indices suggests that the southward displacement of the South Pacific Convergence Zone (SPCZ) during the Little Ice Age with more La Niña events is responsible for the basin-wide increasing of tropical cyclone activity in the South Pacific. Decline of TC occurrence in the western SP during the Medieval Climate Anomaly is attributed to the northward movement of SPCZ. However, event frequency peaks of the latitudinally aligned sites in the South Pacific exhibit a certain degree of asynchrony, necessitating the acquisition of more detailed high-resolution paleostorm reconstructions within these basins and corroborative evidence from global climate models.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113090"},"PeriodicalIF":2.6,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280976","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":"Diverse dinosaur tracks from the Upper Jurassic – Lower Cretaceous Chacarilla Formation of Quebrada de Arcas, northeast Chile: Evidence of high ichnodiversity in an arid palaeoenviroment","authors":"Vincenzo Gesualdi ,&nbsp;Matteo Belvedere ,&nbsp;Marko Yurac ,&nbsp;Dorothee Hippler ,&nbsp;Nejla Hurem ,&nbsp;Christian Salazar ,&nbsp;Javiera Mendez ,&nbsp;Christian A. Meyer","doi":"10.1016/j.palaeo.2025.113088","DOIUrl":"10.1016/j.palaeo.2025.113088","url":null,"abstract":"<div><div>We report diverse dinosaur tracks from siltstone to fine-grained sandstone facies of the Chacarilla Formation, Quebrada de Arcas of northeast Chile. Track-bearing surfaces were studied using 3D modelling and false-colour depth maps, derived from UAV photographs. Five morphotypes are identified based on morphology and morphometric criteria. Morphotype I comprises rounded tracks with a consistent narrow-gauge and resembles the sauropod ichnogenus, <em>Parabrontopodus</em>; diplodocids or titanosaurids are probable trackmakers. Morphotype II is assigned to the theropod ichnotaxon <em>Abelichnus astigerrae</em> and comprises some of the largest theropod tracks ever recorded from South America with a maximum footprint length of 51 cm; the trackmaker was most likely a large carcharodontosaurid, such as <em>Giganotosaurus carolinii</em>. Morphotype III is an indeterminate theropod track, which shows a distinctive and prominent metatarsal impression, but does not closely match any ichnotaxon although it bears some morphometrical affinity to <em>Changpeipus carbonicus</em>. The Morphotypes IV and V both belong to small-sized theropod trackmakers, and resemble Grallatoridae and <em>Kayentapus</em>-like forms, respectively. Additional theropod material cannot be assigned to specific morphotypes or trackmakers, due to poor preservation. Our findings show the existence of three distinct size classes (small, medium and large) of theropod morphotypes and point to a high ichnodiversity at the Jurassic-Cretaceous transition in the subtropical arid environments of Gondwana.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113088"},"PeriodicalIF":2.6,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298980","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":"New age constraints for the Perdasdefogu Basin, Italy: implications for vertebrate paleobiogeography during the early Permian","authors":"Camille Rossignol ,&nbsp;Antoine Logghe ,&nbsp;Vincent Luccisano ,&nbsp;Xiao Shi ,&nbsp;Nathan Cogné ,&nbsp;Marc Poujol ,&nbsp;Alan Pradel ,&nbsp;Sylvie Bourquin ,&nbsp;Gian Luigi Pillola ,&nbsp;Héctor Botella ,&nbsp;Fabrizio Cocco ,&nbsp;Alfredo Loi ,&nbsp;Daniele Fois ,&nbsp;Paolo Stara ,&nbsp;Luigi Sanciu","doi":"10.1016/j.palaeo.2025.113085","DOIUrl":"10.1016/j.palaeo.2025.113085","url":null,"abstract":"<div><div>This study reports new sedimentological, paleontological and geochronological data from the Perdasdefogu Basin, Sardinia, Italy. Sedimentological investigations showed that the basin hosted a permanent lake, initially infilled by epiclastic and volcaniclastic material, then by carbonates, and finally covered by thick felsic volcanic series. Lacustrine sediments yielded various fossils including plant and temnospondyl amphibian remains. Geochronological investigations, performed by U-Pb analyses on zircon, indicate that the Perdasdefogu Basin was being infilled during the early Permian, between 297.9 ± 0.9/3.1 and 295.7 ± 0.7/3.0 Ma (without/with systematic uncertainties propagated, respectively), and covered shortly after, at 295.9 ± 1.1/3.1 Ma, by volcanic series. These age constraints show that the temnospondyls of the Perdasdefogu Basin, located in the southern side of the Variscan belt, were coeval to those of lower Permian basins located in the northern side of the belt. This demonstrates a rather large areal distribution for these fossil amphibians, which encompassed the northern, inner and southern parts of the Variscan belt. This in turn implies probable hydrographic connections that allowed for vertebrate migration between basins located across the belt. While hydrographic networks represent an obvious dispersal mechanism for ichthyofaunas, geochronological and paleontological data from the Perdasdefogu Basin suggest that this dispersal mechanism also holds for tetrapods, at least for aquatic and semi-aquatic groups. The reorganization of hydrographic networks due to the combined effects of climate change and Variscan tectonics could then have represented a driving mechanism for the migration of tetrapods in central Pangea during the late Carboniferous and early Permian.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113085"},"PeriodicalIF":2.6,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239817","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":"Deciphering the diet of the Iberian lynx: Insights from taphonomic analysis of Pleistocene coprolites","authors":"Anna Rufà ,&nbsp;Montserrat Sanz ,&nbsp;Joan Daura","doi":"10.1016/j.palaeo.2025.113086","DOIUrl":"10.1016/j.palaeo.2025.113086","url":null,"abstract":"<div><div>Pleistocene deposits often result from multiple and overlapping contributions. Carnivores play a significant role as bone accumulators in archaeological sites, but identifying the specific agent responsible for a particular accumulation can be challenging. Referential studies provide valuable insights into bone accumulation patterns, but they are based on modern collections and often fail to account for taphonomic biases associated with site formation processes. Here, we present, for the first time, a taphonomic study focused on fossilised Pleistocene Iberian lynx coprolites within the European context. The assemblage, dated to ca. 33 ky B.P., was recovered from layer III of Cova del Gegant, a site identified as a lynx den likely used for rearing cubs. This study is based on previous research at the site and analyses bone remains consumed by the Iberian lynx (<em>Lynx pardinus</em>), recovered from coprolites, to investigate their role in archaeological contexts. The findings are consistent with other lynx accumulations documented in literature, particularly regarding leporid remains. The anatomical proportions in this assemblage are more balanced than other types of accumulations, with a higher representation of cranial elements. Digestive damage is predominant, affecting most bones, especially at moderate and strong degrees. These results enhance our understanding of archaeological accumulation processes and highlight the role of lynxes as bone accumulators. The archaeological evidence from the site indicates that the Iberian lynx inhabited environments and climates that differ significantly from those currently observed. However, the present study suggests that its diet remained relatively consistent with that of contemporary Iberian populations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113086"},"PeriodicalIF":2.6,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263732","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":"Geochemical behavior of redox sensitive trace metals in marine environment and their applications as paleoredox proxies","authors":"Guo Ning ,&nbsp;Jiang Wei ,&nbsp;Li Yueer ,&nbsp;Yu Kefu","doi":"10.1016/j.palaeo.2025.113082","DOIUrl":"10.1016/j.palaeo.2025.113082","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The redox sensitive trace elements (RSTEs) are a group of trace metals that exhibit exceptional sensitivity to redox environments, with their transport and enrichment being constrained by prevailing redox conditions. Most of RSTEs are predominantly found in marine water as dissolved ions and tend to precipitate and accumulate in anoxic sediments under reducing conditions. The distinct behavior of RSTEs, such as rhenium (Re), uranium (U), vanadium (V), and molybdenum (Mo), has led to their widespread use as geochemical indicators to infer the redox state of marine sediments during deposition, and consequently, the oxygen levels in the overlying water and atmosphere. However, there are still gaps in our understanding of the redox transport and transformation processes of some RSTEs, and the application of certain indicators remains limited. In this review, we provide a detailed description of the geochemical behavior of typical RSTEs in the ocean. We also summarize a series of indicators that can be applied as proxies of seawater redox conditions. These indicators are based on the enrichment patterns of certain elements observed under varying redox conditions, including the elemental enrichment factor (TM&lt;sub&gt;EF&lt;/sub&gt;), excess trace metal concentration (TM&lt;sub&gt;XS&lt;/sub&gt;), elemental enrichment degree (TM/Al), bi-elemental ratios (Re/Mo, V/Cr, V/(V + Ni), V/Mn), Mo- and U-EF covariation patterns, and isotopic systems (δ&lt;sup&gt;98&lt;/sup&gt;Mo, δ&lt;sup&gt;238&lt;/sup&gt;U, δ&lt;sup&gt;51&lt;/sup&gt;V, δ&lt;sup&gt;187&lt;/sup&gt;Re). Considering local depositional environmental factors such as water chemistry, operation of Fe-Mn particle shuttle, sedimentation rate, and diagenesis are crucial for interpreting the enrichment patterns and the extent of isotope fractionation of RSTEs in marine sediments, providing valuable insights into the influence of hydrochemical conditions on the geochemical signatures of RSTEs across different geological periods. Therefore, the utilization of multiple independent geochemical proxies on the same sample and comparing data from temporally correlated profiles can yield a more robust and precise information about redox conditions and depositional environments of localized basins. Furthermore, we compiled data on the concentrations of Re, U, V, and Mo, as well as the isotope composition of Mo and U in ancient anoxic marine sediments from 3.5 billion years ago to the present. These data reveal the marine reservoirs of these elements, providing clues to the nature and timing of atmospheric oxidation on Earth. The results suggest that the Great Oxidation Event (GOE) was more like the climax of a long oxidation history starting from the Archean. In the millions of years after the end of the Lomagundi Event, the Earth may have remained well-oxygenated, until the oxygen level declined during the mid-Proterozoic. However, the records reveal at least two brief oxygenation events (ca. 1.4 Ga and 1.1 Ga) within this interval, contradicting the conventional view of ","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113082"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263738","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":"Precipitation variations around ∼4.2 ka BP in the Luoyang Basin: A pollen-based quantitative reconstruction","authors":"Liang Chen ,&nbsp;Zhengchuang Hui ,&nbsp;Zijuan Yong","doi":"10.1016/j.palaeo.2025.113087","DOIUrl":"10.1016/j.palaeo.2025.113087","url":null,"abstract":"<div><div>Luoyang Basin in the Central Plains of China is of great significant in human history because it witnessed a successful transition from Henan Longshan Culture to Erlitou Culture around ∼4.2 ka BP, enabling Chinese civilization to continue uninterruptedly. To explore the climatic and environmental conditions in the Luoyang Basin around 4.2 ka BP, we analyzed pollen assemblages from the HZ-1 section with a chronological framework established by 17 integrated AMS ¹⁴C dates, and reconstructed the histories of bioclimate evolution and precipitation change. Our reconstruction indicates that the precipitation was relatively low and the regional vegetation landscape was dominated by grassland from ∼4990 to ∼4330 cal. yr BP. In the subsequent period from ∼4330 to ∼4155 cal. yr BP, both precipitation and wetland water level reached their highest values accompanied with rather dense forests. In the following period from ∼4155 to ∼3995 cal. yr BP, precipitation became relatively low, and the regional vegetation landscape was dominated by grassland. Between approximately 3995 and 3890 cal. yr BP, the regional climate in the Luoyang Basin underwent a gradual transition—from a short-lived period of slightly enhanced precipitation, characterized by forest expansion and grassland contraction, to a subsequent dry phase marked by the maximum expansion of grassland vegetation. Further analysis reveals that the precipitation variations in the Luoyang Basin during ∼4990 and ∼ 3890 cal. yr BP exhibited an inverse relationship with the sea surface temperature (SST) variations of the Western Pacific warm pool and the associated ENSO-like phases. It should be particularly noted that the precipitation was relatively low around ∼4.2 ka BP in Luoyang Basin. But, if the aridification occurred around ∼4.2 ka BP is examined in the context of a large time window of the period from 5000 to 3600 cal. yr BP, the period around ∼4.2 ka BP was not the driest time within the examined window. This climate condition likely provided an advantageous background for the flourishing of the late Henan Longshan culture in the Luoyang Basin.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113087"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263826","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":"Filling the gap of the late Quaternary planktonic foraminifera record in the Western Mediterranean: Paleoceanographic changes in the Ligurian Sea over the last 27.4 ka","authors":"Pierluigi Martinelli ,&nbsp;Laura Bronzo ,&nbsp;Sergio Bonomo ,&nbsp;Isabel Cacho ,&nbsp;Antonio Cascella ,&nbsp;Letizia Di Bella ,&nbsp;José-Abel Flores ,&nbsp;Jaime Frigola ,&nbsp;Fabrizio Lirer ,&nbsp;Fabrizio Michelangeli ,&nbsp;Mar Selvaggi ,&nbsp;Francisco J. Sierro ,&nbsp;Rocco Gennari","doi":"10.1016/j.palaeo.2025.113078","DOIUrl":"10.1016/j.palaeo.2025.113078","url":null,"abstract":"<div><div>This study aims to expand our understanding of the paleoceanographic changes in the western Mediterranean during the Late Quaternary by investigating the planktonic foraminifera and the reworked coccolith records of the NDT_22_2016 core (27.4 ka cal BP to present) in the Ligurian Sea. To achieve this a robust age model was developed using 17 radiocarbon dates, allowing sub-millennial resolution analyses. The last glacial period (115–11.7 ka cal BP) was characterized by cold-eutrophic species (<em>Globigerinita glutinata, Globigerina bulloides</em> and <em>Turborotalita quinqueloba</em>), while formation of a seasonal deep chlorophyll maximum (DCM) was confined to the south-western Mediterranean as testified by the distribution of <em>Neogloboquadrina incompta</em>. The intervening Heinrich events were identified in the Ligurian Sea through reworked coccolith peaks and the subsequent increase of <em>N. incompta</em>, indicating enhanced runoff and DCM formation, respectively, in response to a northward expansion of the summer warming. Subsequently, during deglaciation, intense warming initiating with the Bølling-Allerød, and interrupted during the Younger Dryas, led to an increase in the abundance of <em>Globoconella inflata</em>, suggesting year-round stratification. The Holocene was subdivided in three phases: an initial rapid warming (up to 10.4 ka cal BP), followed by the development of strong stratification during the second phase (10.4–5.3 ka cal BP), which includes the time interval of sapropel S1 in the Eastern Mediterranean. The second to third phase transition is marked by the appearance of <em>Globorotalia truncatulinoides</em>, signalling a strong seasonal contrast, characterized by strong winter mixing and summer stratification as evidenced also by the presence of <em>N. incompta</em>.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113078"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221268","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":"Skeletal concentrations in upwelling records: greater sensitivity to hiatal duration than to paleo‑oxygenation in the Permian Phosphoria Rock Complex","authors":"Madeline S. Marshall","doi":"10.1016/j.palaeo.2025.113084","DOIUrl":"10.1016/j.palaeo.2025.113084","url":null,"abstract":"<div><div>The Permian Phosphoria Rock Complex (PRC) of Idaho, which is dominated by dark shales, commercial phosphorites, and cherts signifying exceptional productivity, includes a wide array of skeletal concentrations. These range from single-event beds in oxic, oligotrophic settings, dominated by shelly macrobenthos, to taphonomically and diagenetically more complex concentrations of shells, teeth, and other remains that bear evidence of repeated reworking, colonization, and post-mortem modification (hiatal accumulations) under periodically dysoxic and eutrophic conditions. Concentrations can be divided into seven taphonomic types that vary with host lithology (facies) but most strongly with the duration of associated stratigraphic hiatuses, which were inferred independently from discontinuity surfaces. Surfaces include bedding planes (single-event shell bed Types 1–2), bed-set boundaries (multi-event shell bed Types 3–4), flooding surfaces of parasequences (∼250–500 ky spacing) and, more rarely, laterally more extensive 3rd-order surfaces of maximum flooding or starvation (hiatal shell bed Types 5–7). The correlation of taphonomic complexity with hiatal duration suggests that many PRC skeletal concentrations are highly time-averaged, beyond that likely for assemblages from intervening depositional increments, which reflect the nutrient, oxygen, and energy conditions of a single habitat. During episodes of low or zero sediment accumulation, the final assemblage can (and here does) reflect the broader spectrum of skeletal input, taphonomic conditions, and early diagenesis that can arise locally (environmental condensation). The interplay of ancient nutrient regimes on oxygenation and their cascading effects on benthic communities were, somewhat surprisingly, secondary factors.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113084"},"PeriodicalIF":2.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144298985","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":"High-precision U–Pb geochronology of the Guttenberg Carbon Isotope Excursion (GICE) recorded in the Tarim Basin, NW China","authors":"Junjie Xu ,&nbsp;Jahandar Ramezani ,&nbsp;Huaichun Wu ,&nbsp;Qiang Fang ,&nbsp;Jinghui Guo ,&nbsp;Shiling Yang ,&nbsp;Shihong Zhang ,&nbsp;Tianshui Yang ,&nbsp;Zhuyin Chu","doi":"10.1016/j.palaeo.2025.113083","DOIUrl":"10.1016/j.palaeo.2025.113083","url":null,"abstract":"<div><div>The Guttenberg Carbon Isotope Excursion (GICE) is the second significant positive excursion event during the Ordovician, accompanied by climatic change. However, the availability of highly precise geochronology directly associated with the GICE is lacking, impeding its comprehensive understanding. Here, δ¹³C_carb chemostratigraphy is reconstructed to identify the GICE at the Upper Ordovician Yangjikan section in the Tarim Basin, Northwest China. Additionally, we provide the first high-precision <img>U–Pb zircon chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) age of 453.29 ± 0.15 Ma (2σ analytical uncertainty) for a K-bentonite layer at the Yangjikan section. This date constrains the timing of the GICE in the Tarim Basin and indicates its synchronization with GICE records in South China and North America. Furthermore, the occurrence of the GICE coincided with contemporaneous rises in sea level for these regions, potentially suggesting that enhanced primary productivity and subsequent increased organic carbon burial have driven the GICE.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113083"},"PeriodicalIF":2.6,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263825","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}