Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Climate-change induced human migration and socio-political changes in eastern India during the Meghalayan age","authors":"Dipanwita Sengupta ,&nbsp;Som Dutt ,&nbsp;Sophie F. Warken ,&nbsp;Arvinash Singam ,&nbsp;Norbert Frank ,&nbsp;Sumit Sagwal ,&nbsp;Sakshi Maurya","doi":"10.1016/j.palaeo.2025.112873","DOIUrl":"10.1016/j.palaeo.2025.112873","url":null,"abstract":"<div><div>The Holocene climate records, available from the Indian subcontinent are in fragments, majority having low temporal resolution and illustrate regional variability in proxy response. The impact of climate fluctuations on contemporary societies has been discussed in general. However, region specific climate-cultural linkages have not been adequately represented. This study presents a four-millennia-long time-series of Indian Summer Monsoon (ISM) variability from northeastern India using a U-Th dated stalagmite δ¹⁸O time series, particularly emphasising on the human development in eastern and northeastern India. The record exhibits ISM variability during ∼5.5 to ∼1.0 kyr BP. The results indicate weakened ISM conditions during 4.2–4.0 kyr BP and strong phases during 2.74–2.39 kyr BP and 1.42–0.97 kyr BP. The ISM fluctuations over the studied period had been significantly influenced by changes in the North Atlantic Oscillations (NAO), Intertropical Convergence Zone (ITCZ) latitudinal positioning and solar activity through teleconnections. Anthropological, historical and paleoclimatological evidences stitched together elucidate a story of climate induced human development in eastern and northeastern India. Signs of prosperous urban centres were evident in eastern India by ∼2.8 kyr BP and large kingdoms in this region established and rose to power between ∼1.3–0.9 kyr BP, mainly during the moderate to high ISM conditions.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112873"},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629059","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 Middle–Late Pennsylvanian event: Timing and mechanisms","authors":"Yixin Wang,&nbsp;Keyi Hu,&nbsp;Xunyan Ye,&nbsp;Xiangdong Wang","doi":"10.1016/j.palaeo.2025.112893","DOIUrl":"10.1016/j.palaeo.2025.112893","url":null,"abstract":"<div><div>The Late Palaeozoic Ice Age (LPIA) was associated with climate fluctuations, significant biotic changes, the late Desmoinesian extinction, the conodont <em>Idiognathodus</em> diversification, and the “Carboniferous rainforest collapse”. These changes occurred in both marine and terrestrial realms during the Middle–Late Pennsylvanian, approximately 307–303.7 Ma. The timing, mechanisms, and magnitude of these events, especially the marine events, are poorly understood due to the scarcity of continuous Pennsylvanian successions and the challenges of international correlations caused by frequent glacio-eustatic transgressions and regressions during the LPIA. In southern Guizhou, South China, slope carbonate successions were deposited with abundant conodonts, providing opportunities to study these events. Based on materials from the Naqing, Shanglong, and Narao sections, conodont biostratigraphy, strontium and oxygen isotopes of conodont apatite, and carbon isotope of bulk rock across the Middle–Upper Pennsylvanian boundary interval are presented. Conodont zones, namely the late Moscovian <em>Idiognathodus podolskensis</em>, <em>Neognathodus roundyi,</em> and <em>Swadelina</em> sp. A zones, the Kasimovian <em>Sw</em>. <em>subexcelsa</em>, <em>Sw</em>. <em>makhlinae</em>, <em>I</em>. <em>heckeli</em>, <em>I</em>. <em>turbatus</em>, <em>I. magnificus</em>, “<em>I</em>.” <em>guizhouensis</em>, <em>Heckelina eudoraensis</em>, and “<em>I</em>.” <em>naraoensis</em> zones, and the Gzhelian <em>H. simulator</em> Zone are recognized. Focused on late Moscovian to early Kasimovian, three phases of environmental and biotic changes during the <em>Sw</em>. sp. A and <em>I. magnificus</em> zones are recognized. The first to second phases during the <em>Sw</em>. sp. A and <em>Sw</em>. <em>subexcelsa</em> zones are correlated with the dominance of rainforest biomes changing from cordaitaleans and lycopsids to marattialean trees. The second to the third phases during the <em>Sw</em>. <em>subexcelsa</em> and <em>I. magnificus</em> zones correlate with the late Desmoinesian extinction event, and radiation of <em>Idiognathodus</em> species. A general warming trend of ∼4–6 °C temperature rise calculated by δ¹⁸O could partly explain the aridification and collapse of rainforests. Changes in continental weathering were considered to partly drive the extinction and then radiation of conodonts during the middle–late Kasimovian supported by ⁸⁷Sr/⁸⁶Sr and δ¹⁸O of conodont apatite.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112893"},"PeriodicalIF":2.6,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611593","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":"Evaluating planktic foraminiferal resilience during the Middle Eocene Climatic Optimum (MECO) in the Atlantic Ocean","authors":"Silvia Sigismondi ,&nbsp;Valeria Luciani ,&nbsp;Laia Alegret ,&nbsp;Thomas Westerhold","doi":"10.1016/j.palaeo.2025.112867","DOIUrl":"10.1016/j.palaeo.2025.112867","url":null,"abstract":"<div><div>The Middle Eocene Climatic Optimum (MECO), centered around ∼40 Ma, is characterized by a steady decline in marine bulk and benthic carbonate δ¹⁸O values by approximately ∼1 ‰ over ∼400 kyr. This is typically interpreted as a 3–6 °C increase in global temperatures, followed by a rapid return to pre-event conditions. This event is increasingly attracting scientific attention, as it represents a natural experiment of the temperatures and pCO₂ levels that Earth may reach by the end of this century if anthropogenic greenhouse gas emissions are not reduced. The δ¹³C signal, along with biotic and paleoceanographic changes across the MECO, exhibits significant geographic heterogeneity, making this event still enigmatic. In particular, the biotic response remains poorly constrained. Here, we aim to address this gap by focusing on planktic foraminifera, which are highly sensitive to the physical and chemical state of the oceans and can offer a valuable long-term perspective on marine ecosystem resilience to global warming. We selected Ocean Drilling Program Sites 1051, 1263, and 702, which cover different latitudinal settings across the Atlantic Ocean and provide established age models and stable isotope constraints. Planktic foraminifera display a pronounced assemblage turnover across the MECO, primarily related to an increase in surface-water temperature that altered pelagic food webs. The intense warming caused a southward migration of warm-index taxa at Site 702, as also recorded for calcareous nannofossils. The warm-index <em>“</em>Large <em>Acarinina”</em> (&gt;150 μm) shows a marked and permanent decline within ∼250 kyr during the late stage of the MECO at Sites 1051 and 702, approximately 2 Myr before their evolutionary disappearance at the Bartonian-Priabonian boundary. This decline is widespread, being also recorded in the Tethys. We speculate that changes in microalgal symbionts may have impacted the success of this group. We also document a drop in the abundance of the genus <em>Chiloguembelina</em>, possibly related to enhanced oxygenation of its ecological niche, the oxygen deficient zone (ODZ). The planktic foraminiferal assemblages, though demonstrating some degree of plasticity by absorbing periodic stress extremes through community modifications and latitudinal migration, did not recover their pre-disturbance state. This indicates low stability during the MECO event and ultimately lack of resilience.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112867"},"PeriodicalIF":2.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611591","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":"Exploring the association between temperature and multiple ecomorphological traits of biocalcifiers (Brachiopoda)","authors":"Facheng Ye ,&nbsp;Maria Aleksandra Bitner","doi":"10.1016/j.palaeo.2025.112883","DOIUrl":"10.1016/j.palaeo.2025.112883","url":null,"abstract":"<div><div>An increasing number of studies have addressed the varied responses of different phylogenetically specific groups to climate change. However, the dominant mechanisms and robust data-driven evidence remain underexplored. This study investigated the environmental resilience of biocalcifiers, with a focus on living brachiopods – organisms that have persisted throughout Earth's geo-history and serve as vital archives of marine life. By analysing the biogeographical patterns of brachiopods, we assessed the influence of temperature on ecomorphological traits such as species richness, environmental tolerance, shell mineralisation and ornamentation, and other shell morphologies. Using the latest comprehensive database and advanced computational tools, including correlation analysis and machine learning, we uncovered moderate relationships between temperature and these traits. Machine-learning models achieved a temperature prediction performance with a root mean squared error (RMSE) of approximately 5 °C when incorporating all tested variables. Our findings highlight the significant role of macroevolutionary adaptation history in shaping brachiopod biogeographical patterns, as evidenced by strong Spatial Autocorrelation phenomena of the tested ecomorphological-trait variables. This study not only advances our understanding of brachiopod ecology and biogeography but also contributes to broader discussions on climate change, biodiversity, and the resilience of marine ecosystems. By integrating traditional and novel methodologies, we provide a framework for exploring complex ecological interactions, offering insights into the resilience of marine ecosystems and tackling current global challenges.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112883"},"PeriodicalIF":2.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611592","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":"On land record of the Oligocene–Miocene transition. Climatic insights from a multiproxy study on a lacustrine system in the Ebro Basin (NE Iberia, SW Europe)","authors":"C. Arenas ,&nbsp;L. Cabrera ,&nbsp;M.C. Osácar ,&nbsp;F.J. Pérez-Rivarés ,&nbsp;L. Valero ,&nbsp;J. Bastida","doi":"10.1016/j.palaeo.2025.112880","DOIUrl":"10.1016/j.palaeo.2025.112880","url":null,"abstract":"<div><div>The Oligocene–Miocene Transition is associated with climatic changes primarily related to Antarctic phenomena (Mi-1 glacial event), the effects of which are not well known on land. This work examines a continuous, well dated distal-alluvial and carbonate lacustrine and palustrine succession (23.56 to 22.1 Ma) in the Ebro Basin, through sedimentological analysis and carbonate δ¹³C and δ¹⁸O composition, to unveil climate-related variations and compare them with those in other terrestrial and marine Mi-1 records. Results indicate carbonate deposition in freshwater bodies having moderate-to-high plant-derived CO₂ supply and being affected by lake-level variations and evaporative processes (causing Mg carbonates precipitation in the Oligocene alluvial and saline mud flats), within a closed-lake environment. A significant decline in temperature and humidity centered around 23.16–23.14 Ma seems to correlate with Mi-1, but with earlier onset and earlier minimum temperature and humidity (minima <em>ca</em> 80–90 ka before) in the lake system. Low temperature and humidity are followed by oscillating but overall increasing humidity, varying Precipitation/Evaporation and slight warming until 23.1 Ma, coinciding with the development of mainly lacustrine and palustrine environments from <em>ca</em> 23.15 Ma onwards. Two falls in δ¹⁸O that concur with opposed δ¹³C trends, representing dissimilar climatic conditions, appear to match different long-term orbital configurations. The earlier response of the Ebro Basin-lake system to global changes, e.g. the Mi-1 event, is consistent with results from other continental records, and implies the sensitivity of lake systems to record initial stages of ongoing global changes, and the more lagging responses of marine systems to continental ¹²CO₂-input variations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112880"},"PeriodicalIF":2.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684728","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":"Human presence in the southeastern Tibetan Plateau after the Last Glacial Maximum","authors":"Jia-Jing Wang ,&nbsp;Pei-Yang Tan ,&nbsp;Yue Feng ,&nbsp;Zhe-Xuan Zheng ,&nbsp;Yu-Jie Guo ,&nbsp;Jia-Ning He ,&nbsp;You-Ping Wang ,&nbsp;Jia-Fu Zhang","doi":"10.1016/j.palaeo.2025.112878","DOIUrl":"10.1016/j.palaeo.2025.112878","url":null,"abstract":"<div><div>The Tibetan Plateau (TP) is a critical region for understanding patterns of human occupation due to its hostile environment. Numerous archaeological sites have been reported on the plateau, except in its southeastern part. This study presents new archaeological findings from the Congqiancuo area in southeastern Tibet, located in the Haizishan Mountain region, a glacial landscape. Lithic artifacts, including small-sized flake tools and microblades, were discovered on the surface and in a test pit within the low terrace of Congqiancuo Lake, a moraine-dammed lake. Excavation revealed a 1.3-m stratigraphy with four layers, with artifacts found in Layers 3 and 2. Luminescence dating of quartz and K-feldspar grains, along with radiocarbon dating of charcoal, provided age estimates. The luminescence dating results were consistent across quartz and K-feldspar grains, while radiocarbon ages on charcoal were anomalously young. Bayesian statistical modeling refined the luminescence ages, yielding a date of 17.7 ± 1.9 ka for Layer 4, indicating human occupation shortly after the glaciers receded at 18.1 ± 1.4 ka. Cultural layers (Layers 3 and 2) were deposited between 13.8 and 4.2 ka, with the earliest human presence suggested around 11.8 ka. Sediment analysis of grain size and magnetic susceptibility reveals that humans likely inhabited the lake shore during a warmer climate, highlighting southeastern Tibet as a crucial settlement area post-Last Glacial Maximum and a potential route for the spread of microblade technology in high-altitude regions.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112878"},"PeriodicalIF":2.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620445","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":"Millennial-scale vegetation and climate changes in the Sea of Japan region over the last 120 kyr inferred from marine sediments","authors":"Yulia V. Novoselova ,&nbsp;Sergey A. Gorbarenko ,&nbsp;Xuefa Shi ,&nbsp;Aleksandr A. Bosin ,&nbsp;Yanguang Liu","doi":"10.1016/j.palaeo.2025.112892","DOIUrl":"10.1016/j.palaeo.2025.112892","url":null,"abstract":"<div><div>Records of vegetation and climate changes in northeast Asia do exist in abundance. However, continuous dated evidence of regional environmental changes is a rarity, but are very important for comparison with global climate events on a millennial scale. We presented a millennial-scale reconstruction of vegetation changes in the southern part of the Russian Far East during the Last Interglacial, Last Glaciation, and Holocene. The reconstruction is based on analyses of the pollen record from deep-sea sediment core from the Sea of Japan (SJ) and then it was corresponded with the previously constructed by Gorbarenko team age model. We compared vegetation changes with published data on productivity changes and sedimentation in the SJ and with the variability of the East Asian Summer Monsoon (EASM) over the last 120 kyr to determine the dynamics of climate relationships between land and sea on the millennial scale. The oak and other thermophilic species dominated in the region during the strongest Dansgaard–Oeschger (DO) interstadials (DOIs) 24, 23, 18, 17, 14 and 8, indicating warm and wet climate conditions because of rapid climate changes and high activity of EASM. Simultaneously, the surface water primary productivity increased, contributing to the dark layer formation on the bottom. The shrubby alder and cold-hardy birch species spread in the adjacent land during the cold Heinrich stadials (HS) and Dansgaard–Oeschger stadials (DOS) in response to cold conditions because of global climate changes and weak intensity of EASM. The primary productivity mostly decreased in response to climate cooling, favorable to light layers formation in the JS.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112892"},"PeriodicalIF":2.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637323","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":"Indo-Australian Summer Monsoon activity in northern Australia during the past glacial cycle: A flood record of hydroclimate-mediated landscape response to changing runoff","authors":"Teresa Dixon ,&nbsp;Rachel Rudd ,&nbsp;Justine Kemp ,&nbsp;Samuel Marx ,&nbsp;Patrick Moss ,&nbsp;Quan Hua ,&nbsp;Hamish McGowan","doi":"10.1016/j.palaeo.2025.112875","DOIUrl":"10.1016/j.palaeo.2025.112875","url":null,"abstract":"<div><div>Understanding of the Indo-Australian Summer Monsoon's (IASM) response to climate forcings under glacial conditions is limited by a significant knowledge gap regarding the hydroclimate in northern Australia during the last glacial. We present a continuous geochemical record from the eastern Kimberley, Australia, which spans ∼65 ka to the Last Glacial Maximum (LGM). The record comes from the floodplain of the Bullo River, which is currently directly impacted by the IASM, and represents variations in the hydroclimate of its 2000 km² catchment. Results show that the hydroclimate during the glacial lacked the prolonged and high-amplitude changes that marked the hydroclimate following the LGM. Flooding was less frequent or of reduced magnitude than during the deglacial and early Holocene. While there was an absence of substantial long-term change, there is evidence of a subtle shift in mid Marine Isotope Stage 3 to less frequent or lower magnitude flooding and longer instances of dry conditions in the catchment. The low temporal resolution of these results means that centennial or shorter scale periods of enhanced IASM activity cannot be ruled out. These results extend our understanding of the long-term hydroclimate of monsoonal Australia during the glacial, which has, to date, largely been inferred from discontinuous geomorphic records.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112875"},"PeriodicalIF":2.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611511","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":"Dental microwear and diet of the latest Miocene ape in southern China (Lufengpithecus lufengensis)","authors":"Yaobin Fan ,&nbsp;Christopher J. Bae ,&nbsp;Jianrong Liu ,&nbsp;Jiahui Ding ,&nbsp;Wei Liao ,&nbsp;Wei Wang ,&nbsp;Peter S. Ungar","doi":"10.1016/j.palaeo.2025.112869","DOIUrl":"10.1016/j.palaeo.2025.112869","url":null,"abstract":"<div><div><em>Lufengpithecus lufengensis</em> is the latest known Miocene ape in southern China, surviving into an interval of increasingly variable and seasonal conditions approaching the end of the epoch. Inferences of its dietary strategies may help us better understand its flexibility in light of these changing conditions. Previous studies, based solely on dental morphology, suggested that L. <em>lufengensis</em> likely consumed at least some tough foods, but actual evidence of food choice by the species has been lacking. Here, we report on a dental microwear texture analysis of L. <em>lufengensis</em> molars (<em>n</em> = 10) from the Shihuiba site in Yunnan Province, southwest China, dated to 6.9–6.2 Ma. Microwear texture complexity and anisotropy data were generated by white-light confocal profilometry and scale-sensitive fractal analysis and then compared with values for an extant baseline series of primate species with documented differences in diet. Our results indicate that L. <em>lufengensis</em> had a diet similar in central tendencies to tough food feeders, such as <em>Presbytis rubicunda,</em> but significantly different from hard-object feeders, such as <em>Cercocebus atys</em>. Further, <em>L. lufengensis</em> had dispersion of texture complexity values similar to those of extant folivores, but less than those of other primates. This, combined with inferred forested environments and arboreality, is consistent with a varied diet, including folivory, for L. <em>lufengensis.</em> This is consistent with previous assertions that thick enamel in this species was a functional adaptation for tough food rather than hard food consumption. A diet including leaves is seemingly consistent with the flexibility needed for L. <em>lufengensis</em> to respond to increasing seasonal food stress during the Late Miocene in southern China.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112869"},"PeriodicalIF":2.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620019","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-resolution records of the mid-Homerian (Silurian) marine chemistry evolution and graptolite biodiversity across the Lundgreni Event reveal what nearly killed the graptolites","authors":"Jiří Frýda ,&nbsp;Barbora Frýdová","doi":"10.1016/j.palaeo.2025.112866","DOIUrl":"10.1016/j.palaeo.2025.112866","url":null,"abstract":"<div><div>The Silurian Period was characterized by repeated extinctions, carbon cycle fluctuations, and significant climatic shifts. Among the most notable events was the Homerian double-peaked carbon isotope excursion associated with the Mulde and Lundgreni extinctions, both linked to a period of global cooling. The Lundgreni Event was marked by a significant decline in graptolite diversity, while the Mulde Event was characterized by a reduction in conodont diversity. In this study, we present new data that characterize marine palaeoredox conditions in the Prague Basin, peri-Gondwanan terrane, based on high-resolution sampling of a section representing an offshore setting. Our data are derived from the Kosov section, which is known for the most detailed quantitative biostratigraphical record currently available from peri-Gondwana. High-resolution geochemical sampling of graptolite shales from the <em>Cyrtograptus lundgreni</em> Biozone to the <em>Colonograptus ludensis–gerhardi</em> Biozone, provides clear evidence of abrupt changes in marine palaeoredox conditions. The redox-sensitive trace metal data demonstrate that the stratigraphical interval corresponding to the upper <em>Cyrtograptus lundgreni</em> Biozone to the end of <em>Colonograptus praedeubeli-deubeli</em> Biozone represents a period of substantial oxygenation in offshore settings. A comparison of high-resolution chemostratigraphical and biostratigraphical records reveals that this increased oxygenation of offshore environments, which significantly reduced the habitable areas for graptolites, played a key role in the decline of graptolite biodiversity during the Lundgreni Event. This oxygenation correlates with a global sea-level drop, likely triggered by glaciation, and also with the Homerian double-peaked δ¹³C anomaly. In conclusion, the analysis of new high-resolution chemostratigraphical records across the Homerian Lundgreni Event, combined with a high-resolution quantitative graptolite biostratigraphical record from the same section, provides insights into the potential causes of this global marine ecosystem crisis and fills an important gap in our current global dataset for this interval of the Silurian.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112866"},"PeriodicalIF":2.6,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685360","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}