Pub Date : 2025-12-16DOI: 10.1016/j.palaeo.2025.113506
Yao Zhang , Lili Niu , Qiaoyu Cui , Yi Lin , Zhiping Zhang , Jiaju Zhao , Xinwei Yan , Aifeng Zhou
Vegetation ecosystems in the East Asian monsoon margin in northern China are highly sensitive and ecologically vulnerable. Understanding long-term vegetation dynamics and their responses to abrupt climate events is critical for guiding ecological conservation and sustainable land-use planning. In this study, we reconstructed vegetation dynamics using a high-resolution pollen record from the Qixing peatland in the Saihanba region. Results indicated that climate was the primary driver of vegetation changes, while temperature and precipitation variations were asynchronous. The mid-Holocene was characterized by maximum precipitation; however, an abrupt cooling event between 7000 and 5500 cal yr BP triggered a rapid decline in deciduous broadleaf trees alongside a concurrent expansion of herbaceous vegetation, ultimately leading to steppe-dominated ecosystems. This transition was accompanied by reduced vegetation diversity and increased spatial heterogeneity. Subsequently, coniferous forests dominated by Pinus, as a major component of the secondary vegetation, became prevalent. However, a sudden shift to aridity around 5000 cal yr BP associated with the weakening of the East Asian summer monsoon prompted a rapid spread of herbs, along with a recovery in diversity and evenness. This study demonstrates that abrupt climate shifts caused forest retreat and grassland expansion once critical climatic thresholds were exceeded across the monsoon marginal zone. Given the current context of accelerated climate warming and increasingly frequent extreme climatic events, urgent protective measures are essential for these highly vulnerable ecosystems.
中国北方东亚季风边缘植被生态系统具有高度敏感性和生态脆弱性。了解植被长期动态及其对气候突变事件的响应对于指导生态保护和土地利用可持续规划具有重要意义。本文利用塞罕坝地区七星泥炭地的高分辨率花粉记录重建了植被动态。结果表明，气候是植被变化的主要驱动力，而温度和降水的变化是不同步的。中全新世以最大降水为特征；然而，在7000 - 5500 cal - yr BP之间的一次突然变冷事件引发了落叶阔叶树的迅速减少，同时草本植被的扩张，最终导致了草原为主的生态系统。这一转变伴随着植被多样性的减少和空间异质性的增加。随后，以松林为主的针叶林成为次生植被的主要组成部分。然而，在距今5000万年左右，东亚夏季风减弱导致了干旱的突然转变，促使草本植物迅速传播，多样性和均匀性也随之恢复。该研究表明，一旦超过季风边缘带的临界气候阈值，气候突变会导致森林退缩和草地扩张。在当前气候变暖加速和极端气候事件日益频繁的背景下，对这些高度脆弱的生态系统采取紧急保护措施至关重要。
{"title":"Vegetation responses to the mid-Holocene abrupt climate events in the Forest-Steppe Ecotone in northern China","authors":"Yao Zhang , Lili Niu , Qiaoyu Cui , Yi Lin , Zhiping Zhang , Jiaju Zhao , Xinwei Yan , Aifeng Zhou","doi":"10.1016/j.palaeo.2025.113506","DOIUrl":"10.1016/j.palaeo.2025.113506","url":null,"abstract":"<div><div>Vegetation ecosystems in the East Asian monsoon margin in northern China are highly sensitive and ecologically vulnerable. Understanding long-term vegetation dynamics and their responses to abrupt climate events is critical for guiding ecological conservation and sustainable land-use planning. In this study, we reconstructed vegetation dynamics using a high-resolution pollen record from the Qixing peatland in the Saihanba region. Results indicated that climate was the primary driver of vegetation changes, while temperature and precipitation variations were asynchronous. The mid-Holocene was characterized by maximum precipitation; however, an abrupt cooling event between 7000 and 5500 cal yr BP triggered a rapid decline in deciduous broadleaf trees alongside a concurrent expansion of herbaceous vegetation, ultimately leading to steppe-dominated ecosystems. This transition was accompanied by reduced vegetation diversity and increased spatial heterogeneity. Subsequently, coniferous forests dominated by <em>Pinus</em>, as a major component of the secondary vegetation, became prevalent. However, a sudden shift to aridity around 5000 cal yr BP associated with the weakening of the East Asian summer monsoon prompted a rapid spread of herbs, along with a recovery in diversity and evenness. This study demonstrates that abrupt climate shifts caused forest retreat and grassland expansion once critical climatic thresholds were exceeded across the monsoon marginal zone. Given the current context of accelerated climate warming and increasingly frequent extreme climatic events, urgent protective measures are essential for these highly vulnerable ecosystems.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113506"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799344","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}
Pub Date : 2025-12-16DOI: 10.1016/j.palaeo.2025.113505
Carlos S. Melo , José Madeira , Ricardo S. Ramalho , Ana C. Rebelo , Michael W. Rasser , Esther Martín-González , Alfred Uchman , Carlos Marques da Silva , Emílio Rolán , Luís Silva , Joseph A. Stewart , Laura F. Robinson , Deirdre D. Ryan , Alessio Rovere , Antje Voelker , Patrícia Madeira , Mário Cachão , Sérgio P. Ávila
The geological study of Marine Isotopic Stage (MIS) 11c (424–397 ka) is key to reconstructing the climatic and oceanographic conditions during one of the longest and the warmest interglacial in the last 1 million years. Moreover, interglacial MIS 11c is considered as an important analogue for our near future in times of climate change, under anthropogenic emissions scenarios, due to its similar orbital forcing configuration. Here we present the results of a comprehensive analysis of one of the most extensive Quaternary fossiliferous sedimentary successions in the Cabo Verde archipelago in the tropical northeastern Atlantic. The Nossa Senhora da Luz Bay (Santiago Island) is one of the few MIS 11 fossiliferous sites known in Macaronesia. The sedimentary succession records a set of transitions between fluvial and marine environments, and emersion and immersion events within a confined, highly protected bay environment. A thick layer of fine-branched rhodoliths in its upper part suggests ecological conditions that no longer exist in Cabo Verde. The presence of specimens of the intertidal clam Senilia senilis in life position ∼12 m above present-day mean sea level leads us to reinterpret the relative sea-level changes at Santiago Island and show that the uplift trend since MIS 11c is an order of magnitude lower (0.01 mm/yr) than previously calculated (0.10 to 0.14 mm/yr). The fossil assemblage includes representatives of five phyla, with molluscs being the most diverse and abundant. Despite the abundance of some bivalves (Saccostrea cuccullata, S. senilis, and Aequipecten opercularis), and gastropods (Thetystrombus latus and Thais nodosa), and some horizons showing the crustacean burrows Thalassinoides suevicus, the general biodiversity is low. The presence of S. cuccullata and S. senilis, both absent from present-day Cabo Verde archipelago, indicates a tropical, more humid climate in this region, during MIS 11c.
{"title":"Sedimentary facies and invertebrate faunal exchange confirm humid conditions in the tropical eastern Atlantic during interglacial Marine Isotopic Stage (MIS) 11c","authors":"Carlos S. Melo , José Madeira , Ricardo S. Ramalho , Ana C. Rebelo , Michael W. Rasser , Esther Martín-González , Alfred Uchman , Carlos Marques da Silva , Emílio Rolán , Luís Silva , Joseph A. Stewart , Laura F. Robinson , Deirdre D. Ryan , Alessio Rovere , Antje Voelker , Patrícia Madeira , Mário Cachão , Sérgio P. Ávila","doi":"10.1016/j.palaeo.2025.113505","DOIUrl":"10.1016/j.palaeo.2025.113505","url":null,"abstract":"<div><div>The geological study of Marine Isotopic Stage (MIS) 11c (424–397 ka) is key to reconstructing the climatic and oceanographic conditions during one of the longest and the warmest interglacial in the last 1 million years. Moreover, interglacial MIS 11c is considered as an important analogue for our near future in times of climate change, under anthropogenic emissions scenarios, due to its similar orbital forcing configuration. Here we present the results of a comprehensive analysis of one of the most extensive Quaternary fossiliferous sedimentary successions in the Cabo Verde archipelago in the tropical northeastern Atlantic. The Nossa Senhora da Luz Bay (Santiago Island) is one of the few MIS 11 fossiliferous sites known in Macaronesia. The sedimentary succession records a set of transitions between fluvial and marine environments, and emersion and immersion events within a confined, highly protected bay environment. A thick layer of fine-branched rhodoliths in its upper part suggests ecological conditions that no longer exist in Cabo Verde. The presence of specimens of the intertidal clam <em>Senilia senilis</em> in life position ∼12 m above present-day mean sea level leads us to reinterpret the relative sea-level changes at Santiago Island and show that the uplift trend since MIS 11c is an order of magnitude lower (0.01 mm/yr) than previously calculated (0.10 to 0.14 mm/yr). The fossil assemblage includes representatives of five phyla, with molluscs being the most diverse and abundant. Despite the abundance of some bivalves (<em>Saccostrea cuccullata</em>, <em>S. senilis</em>, and <em>Aequipecten opercularis</em>), and gastropods (<em>Thetystrombus latus</em> and <em>Thais nodosa</em>), and some horizons showing the crustacean burrows <em>Thalassinoides suevicus</em>, the general biodiversity is low. The presence of <em>S. cuccullata</em> and <em>S. senilis</em>, both absent from present-day Cabo Verde archipelago, indicates a tropical, more humid climate in this region, during MIS 11c.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113505"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885192","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}
Pub Date : 2025-12-16DOI: 10.1016/j.palaeo.2025.113493
Kaixuan An , Jialun Huang , Xiubin Lin , Hanlin Chen , Yong Li , Xianzhang Yang , Liang Zhang , Cai Chen , Jinkai Xia , Xiaogan Cheng , Fengqi Zhang , Ziyi Wang , Lin Jiang , Zhuxin Chen , Beiwei Luo , Nan Su
The Cenozoic collision between the Indian and Eurasian plates caused widespread intracontinental deformation, which accommodated roughly half of the present-day India-Eurasia convergence rate. However, the mechanisms driving such intracontinental convergence remain debated, particularly regarding the vertically coherent pure-shear thickening model and the decoupled crustal-scale deformation model. The South Tian Shan and the Tarim Basin record substantial Cenozoic intracontinental convergence, and the Kashi foreland basin preserves abundant synorogenic strata, providing a key archive to test these competing models. Herein, we conducted sedimentological and detrital zircon UPb geochronological analyses of the Neogene–Quaternary strata in the Alparlek section. Stratigraphic observations reveal an overall upward-coarsening facies succession, reflecting a transition from the low-energy depositional environments of the early–middle Miocene Keziluoyi–Pakabulake Formations to the high-energy alluvial systems of the late Miocene–Quaternary Artux–Xiyu Formations. This sedimentary evolution indicates a progressive advance of thrust-induced flexural loading and corresponding basinward migration of the Kashi foreland basin since the mid-Miocene. Detrital zircon UPb age distributions further document episodic provenance shifts between the South Tian Shan and the northern Tarim Basin, indicating the multistage, basinward growth of foreland fold-and-thrust belts and a migrating orogen–basin boundary. Integrated with previous geophysical studies, these findings indicate that the Neogene intracontinental convergence between the South Tian Shan and the Tarim Basin occurred in a decoupled mode, characterised by southward thrusting of the upper crust of the northern Tarim Basin and the northward underthrusting of its lower crust beneath the South Tian Shan.
{"title":"Decoupled intracontinental convergence between the South Tian Shan and northern Tarim Basin since the Neogene: Constraints from stratigraphy and detrital zircon UPb geochronology of the Alparlek section","authors":"Kaixuan An , Jialun Huang , Xiubin Lin , Hanlin Chen , Yong Li , Xianzhang Yang , Liang Zhang , Cai Chen , Jinkai Xia , Xiaogan Cheng , Fengqi Zhang , Ziyi Wang , Lin Jiang , Zhuxin Chen , Beiwei Luo , Nan Su","doi":"10.1016/j.palaeo.2025.113493","DOIUrl":"10.1016/j.palaeo.2025.113493","url":null,"abstract":"<div><div>The Cenozoic collision between the Indian and Eurasian plates caused widespread intracontinental deformation, which accommodated roughly half of the present-day India-Eurasia convergence rate. However, the mechanisms driving such intracontinental convergence remain debated, particularly regarding the vertically coherent pure-shear thickening model and the decoupled crustal-scale deformation model. The South Tian Shan and the Tarim Basin record substantial Cenozoic intracontinental convergence, and the Kashi foreland basin preserves abundant synorogenic strata, providing a key archive to test these competing models. Herein, we conducted sedimentological and detrital zircon U<img>Pb geochronological analyses of the Neogene–Quaternary strata in the Alparlek section. Stratigraphic observations reveal an overall upward-coarsening facies succession, reflecting a transition from the low-energy depositional environments of the early–middle Miocene Keziluoyi–Pakabulake Formations to the high-energy alluvial systems of the late Miocene–Quaternary Artux–Xiyu Formations. This sedimentary evolution indicates a progressive advance of thrust-induced flexural loading and corresponding basinward migration of the Kashi foreland basin since the mid-Miocene. Detrital zircon U<img>Pb age distributions further document episodic provenance shifts between the South Tian Shan and the northern Tarim Basin, indicating the multistage, basinward growth of foreland fold-and-thrust belts and a migrating orogen–basin boundary. Integrated with previous geophysical studies, these findings indicate that the Neogene intracontinental convergence between the South Tian Shan and the Tarim Basin occurred in a decoupled mode, characterised by southward thrusting of the upper crust of the northern Tarim Basin and the northward underthrusting of its lower crust beneath the South Tian Shan.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113493"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799194","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}
Pub Date : 2025-12-15DOI: 10.1016/j.palaeo.2025.113504
Imre Andreas Martin , Leho Ainsaar , Aivo Lepland , Alicja Wudarska , Maria Rosa Scicchitano , Tony Prave
The Vidukle-61 core, located in the Baltic Basin of central Lithuania, contains an excellent record of the Mid-Ludfordian Carbon Isotope Excursion (MLCIE; c. 1 Myr duration) identified by carbonate δ13C values rising steadily from c. 0 ‰ to 8 ‰, followed by a return to c. 0 ‰ through a 40-m thick interval of marine limestone. Here, we report carbon and oxygen (CO) isotope data obtained by secondary ion mass spectrometry (SIMS) on two samples (VID-1 and VID-3) of bioclastic packstone from the zenith of the MLCIE. As reported in a previous study, the two samples have bulk-rock values of 7.37 ‰ and 8.17 ‰ for δ13C and − 5.27 ‰ and − 4.68 ‰ for δ18O (values relative to VPDB and repeatability ±0.1 ‰). In contrast, high-spatial-resolution SIMS analyses of the same samples show δ13C values for the calcitic matrix and spar cement ranging between c. 5 ‰ and 11 ‰, and for fossil fragments between c. 6 ‰ and 13 ‰. δ18O SIMS values of individual components vary by up to ±2 ‰ relative to the bulk-rock baseline values. Based on SIMS results and observed isotopic variations between individual components, we attribute the bulk-rock values as an admixture of original seawater CO isotope compositions that are best preserved in the bioclasts and the isotopic compositions of later-stage fluids from which spar and matrix-bound microspar precipitated. Our findings emphasize the significant differences between component-specific and bulk-rock CO isotope values. While δ13Cbulk curves may capture broad temporal trends in the carbon cycle, high-spatial-resolution and component-specific data reveal microscale isotopic heterogeneity, which can deviate considerably from bulk-rock values. Differentiating and identifying the values that best record original carbonate CO isotopic compositions, even in well-preserved carbonate rocks, requires micro-scale studies to resolve C-isotope heterogeneity in carbonate rocks.
{"title":"Component-specific carbon and oxygen isotope variability in marine limestones of the Mid-Ludfordian (late Silurian) carbon isotope excursion of the Baltic Basin","authors":"Imre Andreas Martin , Leho Ainsaar , Aivo Lepland , Alicja Wudarska , Maria Rosa Scicchitano , Tony Prave","doi":"10.1016/j.palaeo.2025.113504","DOIUrl":"10.1016/j.palaeo.2025.113504","url":null,"abstract":"<div><div>The Vidukle-61 core, located in the Baltic Basin of central Lithuania, contains an excellent record of the Mid-Ludfordian Carbon Isotope Excursion (MLCIE; c. 1 Myr duration) identified by carbonate δ<sup>13</sup>C values rising steadily from c. 0 ‰ to 8 ‰, followed by a return to c. 0 ‰ through a 40-m thick interval of marine limestone. Here, we report carbon and oxygen (C<img>O) isotope data obtained by secondary ion mass spectrometry (SIMS) on two samples (VID-1 and VID-3) of bioclastic packstone from the zenith of the MLCIE. As reported in a previous study, the two samples have bulk-rock values of 7.37 ‰ and 8.17 ‰ for δ<sup>13</sup>C and − 5.27 ‰ and − 4.68 ‰ for δ<sup>18</sup>O (values relative to VPDB and repeatability ±0.1 ‰). In contrast, high-spatial-resolution SIMS analyses of the same samples show δ<sup>13</sup>C values for the calcitic matrix and spar cement ranging between c. 5 ‰ and 11 ‰, and for fossil fragments between c. 6 ‰ and 13 ‰. δ<sup>18</sup>O SIMS values of individual components vary by up to ±2 ‰ relative to the bulk-rock baseline values. Based on SIMS results and observed isotopic variations between individual components, we attribute the bulk-rock values as an admixture of original seawater C<img>O isotope compositions that are best preserved in the bioclasts and the isotopic compositions of later-stage fluids from which spar and matrix-bound microspar precipitated. Our findings emphasize the significant differences between component-specific and bulk-rock C<img>O isotope values. While δ<sup>13</sup>C<sub>bulk</sub> curves may capture broad temporal trends in the carbon cycle, high-spatial-resolution and component-specific data reveal microscale isotopic heterogeneity, which can deviate considerably from bulk-rock values. Differentiating and identifying the values that best record original carbonate C<img>O isotopic compositions, even in well-preserved carbonate rocks, requires micro-scale studies to resolve C-isotope heterogeneity in carbonate rocks.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113504"},"PeriodicalIF":2.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799343","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}
Pub Date : 2025-12-15DOI: 10.1016/j.palaeo.2025.113501
Valerii E. Pimenov , Maria M. Pevzner , Natalia G. Mazei , Andrey N. Tsyganov , Ekaterina G. Ershova , Yuri A. Mazei
Studying vegetation dynamics in the regions with high volcanic activity is crucial for understanding ecosystem responses to environmental disturbances and predicting future ecological changes. However, the impacts of tephra deposition on vegetation at local and regional scales remain poorly quantified, limiting understanding of ecosystem resilience to volcanic disturbances. This study presents a high-resolution, multiproxy palaeobotanical record from the Kumroch peatland (Kamchatka, Eurasian Far East), integrating detailed tephrostratigraphy, radiocarbon ages, pollen, plant macrofossil, and loss on ignition data. The peat sequence spans the last ∼5 kyr, anchored by 28 recorded tephra layers. Birch forests (Betula ermanii) and alder shrublands (Alnus alnobetula subsp. fruticosa) dominated during the Middle and Late Holocene, with their proportions shifting in response to climate variations. These changes align in timing with the Late Holocene climate oscillations, primarily reflecting temperature fluctuations. Tephra fallout events had no persistent impact on regional vegetation and limited effects on the local vegetation. These findings demonstrate the resilience of boreal ecosystems to tephra deposition across volcanically active areas and underscore the importance of large-scale studies for understanding ashfall-related disturbances.
{"title":"How volcanoes affect boreal mires: Climate-driven regional vegetation changes and stage-dependent responses to tephra fallout in Kamchatka during the Late Holocene","authors":"Valerii E. Pimenov , Maria M. Pevzner , Natalia G. Mazei , Andrey N. Tsyganov , Ekaterina G. Ershova , Yuri A. Mazei","doi":"10.1016/j.palaeo.2025.113501","DOIUrl":"10.1016/j.palaeo.2025.113501","url":null,"abstract":"<div><div>Studying vegetation dynamics in the regions with high volcanic activity is crucial for understanding ecosystem responses to environmental disturbances and predicting future ecological changes. However, the impacts of tephra deposition on vegetation at local and regional scales remain poorly quantified, limiting understanding of ecosystem resilience to volcanic disturbances. This study presents a high-resolution, multiproxy palaeobotanical record from the Kumroch peatland (Kamchatka, Eurasian Far East), integrating detailed tephrostratigraphy, radiocarbon ages, pollen, plant macrofossil, and loss on ignition data. The peat sequence spans the last ∼5 kyr, anchored by 28 recorded tephra layers. Birch forests (<em>Betula ermanii</em>) and alder shrublands (<em>Alnus alnobetula</em> subsp. <em>fruticosa</em>) dominated during the Middle and Late Holocene, with their proportions shifting in response to climate variations. These changes align in timing with the Late Holocene climate oscillations, primarily reflecting temperature fluctuations. Tephra fallout events had no persistent impact on regional vegetation and limited effects on the local vegetation. These findings demonstrate the resilience of boreal ecosystems to tephra deposition across volcanically active areas and underscore the importance of large-scale studies for understanding ashfall-related disturbances.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113501"},"PeriodicalIF":2.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799342","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}
Pub Date : 2025-12-15DOI: 10.1016/j.palaeo.2025.113503
Shanggui Gong , Yongbo Peng , Laurie C. Anderson , Annette Summers Engel , Huiming Bao
The oxygen and sulfur isotope compositions of carbonate-associated sulfate (CAS) in biogenic materials, such as mollusk shells, are valuable for inferring paleo-seawater sulfate isotope signatures. However, infaunal species may incorporate sulfate from sediment porewater or, in chemosymbiotic taxa, sulfate metabolized by endosymbiotic sulfur-oxidizing bacteria. To evaluate whether shell CAS primarily records seawater or an ecological niche signature, we measured the δ34S and δ18O of CAS from 24 modern and Holocene mollusk species spanning epifaunal, shallow infaunal, deep infaunal, and lucinid (chemosymbiotic) habitats across the northeastern Gulf of Mexico, Bahamas and Mexico. Results show substantial isotopic variability (δ34SCAS: 15.1–22.6 ‰; δ18OCAS: 8.5–14.3 ‰): 1) Epifaunal and lucinid δ34SCAS values cluster near seawater values, while shallow infauna exhibits the greatest variability (up to 7.5 ‰ range), and deep infauna consistently show lower δ34SCAS (17.1–19.9 ‰) than seawater. 2) All taxa exhibit δ18OCAS enrichment above seawater. The absence of 34S-enrichment in infauna suggests limited porewater sulfate incorporation. Epifaunal δ34SCAS values span a 2.6 ‰ range, with a minimum of 19.5 ‰, implying contributions from non-seawater sulfate, likely dietary sulfur or intracrystalline organic sulfate. Reduced δ34SCAS in deep infauna also supports these additional sulfate sources incorporation, as deep infauna increased reliance on deposit-feeding of deeper sediment organic matter characterized by decreasing δ34S value. For shallow infauna, their larger variability in δ34SCAS stems from diverse feeding strategies (filter- and deposit-feeding) and niche adaptations. Bulk CAS of shallow-water lucinid species archive limited 34S-depeted signal of endosymbiont-derived sulfate. CAS oxygen isotope is consistently enriched due to vital effects, with highly variable δ18OCAS value across all niches supporting multiple sulfate sources in shells. These findings demonstrate that mollusk shell CAS does not purely record seawater sulfate but incorporates ecological signatures, underscoring the importance of species-specific biology in CAS-based paleoenvironmental or symbiosis studies.
{"title":"Carbonate-associated sulfate isotope signatures in marine mollusk shells","authors":"Shanggui Gong , Yongbo Peng , Laurie C. Anderson , Annette Summers Engel , Huiming Bao","doi":"10.1016/j.palaeo.2025.113503","DOIUrl":"10.1016/j.palaeo.2025.113503","url":null,"abstract":"<div><div>The oxygen and sulfur isotope compositions of carbonate-associated sulfate (CAS) in biogenic materials, such as mollusk shells, are valuable for inferring paleo-seawater sulfate isotope signatures. However, infaunal species may incorporate sulfate from sediment porewater or, in chemosymbiotic taxa, sulfate metabolized by endosymbiotic sulfur-oxidizing bacteria. To evaluate whether shell CAS primarily records seawater or an ecological niche signature, we measured the δ<sup>34</sup>S and δ<sup>18</sup>O of CAS from 24 modern and Holocene mollusk species spanning epifaunal, shallow infaunal, deep infaunal, and lucinid (chemosymbiotic) habitats across the northeastern Gulf of Mexico, Bahamas and Mexico. Results show substantial isotopic variability (δ<sup>34</sup>S<sub>CAS</sub>: 15.1–22.6 ‰; δ<sup>18</sup>O<sub>CAS</sub>: 8.5–14.3 ‰): 1) Epifaunal and lucinid δ<sup>34</sup>S<sub>CAS</sub> values cluster near seawater values, while shallow infauna exhibits the greatest variability (up to 7.5 ‰ range), and deep infauna consistently show lower δ<sup>34</sup>S<sub>CAS</sub> (17.1–19.9 ‰) than seawater. 2) All taxa exhibit δ<sup>18</sup>O<sub>CAS</sub> enrichment above seawater. The absence of <sup>34</sup>S-enrichment in infauna suggests limited porewater sulfate incorporation. Epifaunal δ<sup>34</sup>S<sub>CAS</sub> values span a 2.6 ‰ range, with a minimum of 19.5 ‰, implying contributions from non-seawater sulfate, likely dietary sulfur or intracrystalline organic sulfate. Reduced δ<sup>34</sup>S<sub>CAS</sub> in deep infauna also supports these additional sulfate sources incorporation, as deep infauna increased reliance on deposit-feeding of deeper sediment organic matter characterized by decreasing δ<sup>34</sup>S value. For shallow infauna, their larger variability in δ<sup>34</sup>S<sub>CAS</sub> stems from diverse feeding strategies (filter- and deposit-feeding) and niche adaptations. Bulk CAS of shallow-water lucinid species archive limited <sup>34</sup>S-depeted signal of endosymbiont-derived sulfate. CAS oxygen isotope is consistently enriched due to vital effects, with highly variable δ<sup>18</sup>O<sub>CAS</sub> value across all niches supporting multiple sulfate sources in shells. These findings demonstrate that mollusk shell CAS does not purely record seawater sulfate but incorporates ecological signatures, underscoring the importance of species-specific biology in CAS-based paleoenvironmental or symbiosis studies.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113503"},"PeriodicalIF":2.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799355","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}
Pub Date : 2025-12-13DOI: 10.1016/j.palaeo.2025.113494
Qingqing Lei , Xiaofan Wan , Xiang Ge , Xiaowei Zeng , Chuanbo Shen
The Qiangtang Terrane preserves a complete geological record documenting the growth of the central Tibetan Plateau; however, its thermo-tectonic evolution and the timing of topographic development remains debated. This study employs multi-system thermochronology (zircon U–Pb, apatite U–Pb, apatite fission track, apatite (U–Th)/He) of sedimentary strata and magmatic rocks from the Qiangtang Terrane to reconstruct its thermal history. The new thermochronological data show that zircon and apatite U–Pb geochronology from Late Triassic and Eocene igneous rocks yield ages in close agreement at ∼220 Ma and ∼ 35 Ma, respectively. Apatite fission track ages range from 121.2 ± 2.7 Ma to 39.3 ± 2.7 Ma, while AHe ages are between 72.5 ± 1.5 Ma and 27.2 ± 0.6 Ma. Integration of these geochronological data with thermal history modeling constrains four distinct tectonic phases: (1) post-magmatic cooling following the South–North Qiangtang collision during the Late Triassic (∼220 Ma), (2) tectonic deformation and uplift related to the Lhasa–Qiangtang collision during the Late Cretaceous (∼90 Ma), (3) magmatic activity in response to intracontinental subduction during the Eocene (55–36 Ma), and (4) tectonic transition triggered by lithospheric mantle delamination since the post-Oligocene (<35 Ma). Furthermore, by synthesizing previous studies on regional exhumation, magmatic activity, fault systems, and palaeoelevation, this study supports the “Proto-Tibetan Plateau” model and provides new insights into the pulsed growth of the central Tibetan Plateau. Eocene deep-seated magmatic processes generated crustal thickness capable of isostatically sustaining a plateau, which then experienced its final uplift after the Oligocene.
采用多系统热年代学方法（锆石U-Pb、磷灰石U-Pb、磷灰石裂变径迹、磷灰石(U-Th)/He）重建羌塘地体沉积地层和岩浆岩的热历史。新的热年代学数据表明，晚三叠世和始新世火成岩的锆石和磷灰石U-Pb年代学结果分别在~ 220 Ma和~ 35 Ma接近一致。磷灰石裂变径迹年龄范围为121.2±2.7 Ma ~ 39.3±2.7 Ma， AHe年龄范围为72.5±1.5 Ma ~ 27.2±0.6 Ma。将这些地质年代学数据与热历史模拟相结合，约束了四个不同的构造阶段：(1)晚三叠世（~ 220 Ma）南-北羌塘碰撞引起的岩浆后冷却，(2)晚白垩世（~ 90 Ma）拉萨-羌塘碰撞引起的构造变形和隆升，(3)始新世（55-36 Ma）陆内俯冲引起的岩浆活动，(4)后渐新世（<35 Ma）以来岩石圈地幔剥离引起的构造转变。始新世深部岩浆作用产生的地壳厚度能够在均衡上维持一个高原，然后在渐新世之后经历了最终的隆起。
{"title":"Multi-system geochronometer constraints on thermo-tectonic evolution of the Qiangtang Terrane, central Tibetan Plateau","authors":"Qingqing Lei , Xiaofan Wan , Xiang Ge , Xiaowei Zeng , Chuanbo Shen","doi":"10.1016/j.palaeo.2025.113494","DOIUrl":"10.1016/j.palaeo.2025.113494","url":null,"abstract":"<div><div>The Qiangtang Terrane preserves a complete geological record documenting the growth of the central Tibetan Plateau; however, its thermo-tectonic evolution and the timing of topographic development remains debated. This study employs multi-system thermochronology (zircon U–Pb, apatite U–Pb, apatite fission track, apatite (U–Th)/He) of sedimentary strata and magmatic rocks from the Qiangtang Terrane to reconstruct its thermal history. The new thermochronological data show that zircon and apatite U–Pb geochronology from Late Triassic and Eocene igneous rocks yield ages in close agreement at ∼220 Ma and ∼ 35 Ma, respectively. Apatite fission track ages range from 121.2 ± 2.7 Ma to 39.3 ± 2.7 Ma, while AHe ages are between 72.5 ± 1.5 Ma and 27.2 ± 0.6 Ma. Integration of these geochronological data with thermal history modeling constrains four distinct tectonic phases: (1) post-magmatic cooling following the South–North Qiangtang collision during the Late Triassic (∼220 Ma), (2) tectonic deformation and uplift related to the Lhasa–Qiangtang collision during the Late Cretaceous (∼90 Ma), (3) magmatic activity in response to intracontinental subduction during the Eocene (55–36 Ma), and (4) tectonic transition triggered by lithospheric mantle delamination since the post-Oligocene (<35 Ma). Furthermore, by synthesizing previous studies on regional exhumation, magmatic activity, fault systems, and palaeoelevation, this study supports the “Proto-Tibetan Plateau” model and provides new insights into the pulsed growth of the central Tibetan Plateau. Eocene deep-seated magmatic processes generated crustal thickness capable of isostatically sustaining a plateau, which then experienced its final uplift after the Oligocene.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113494"},"PeriodicalIF":2.7,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799357","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}
Pub Date : 2025-12-11DOI: 10.1016/j.palaeo.2025.113454
Xi-yang Zhang , Ming-zhuang Wang , Qi Shi , Fei Tan , Guo-tao Zhang , Si-qi Chen , Hong-qiang Yang
Beachrock cementation, mediated by physicochemical and biological processes, plays a pivotal role in the rapid lithification of coastal sediments. Distinguishing between biotic and abiotic carbonate cements is critical for quantitatively reconstructing diagenetic pathways and accurately evaluating paleoenvironmental conditions. We analyzed Holocene beachrocks from Hainan and the Xisha Islands to compare their cement types. Beachrocks from Hainan are characterized by isopachous high-Mg calcite (HMC) rinds, HMC-rich peloidal fabrics, and blocky–drusy low-Mg calcite (LMC), whereas those from the Xisha Islands are dominated by acicular aragonite. HMC rinds composed of equilong fibrous crystals represent marine phreatic cements with minimal diagenetic alteration, whereas LMC forms through meteoric vadose processes, as indicated by red cathodoluminescent rings. Acicular aragonite nucleates within organic-rich micrite envelopes, with its rapid growth governed primarily by inorganic mechanisms. Peloidal fabrics exhibit distinct fluorescence patterns, dull cathodoluminescence, and elevated Mn/Fe ratios, consistent with their interpretation as microbially mediated precipitates formed during organic matter degradation under intermittently reducing conditions. Notably, peloidal fabrics and aragonite are enriched in bioactive metals (V, Fe, Zn, Pb) relative to coral Porites, consistent with active microbial metabolism. Unlike HMC rinds and acicular aragonite, peloidal fabrics display high total rare earth element (REE) contents, uniform REE distributions, LREE depletion (low LREE/HREE), negative Ce anomalies, positive La anomalies, Y/Ho ratios (∼45), and REE partitioning patterns closely matching modern seawater. These distinctive geochemical signatures establish peloidal fabrics as high-fidelity, high-resolution archives of paleo-seawater chemistry, providing a robust tool for deciphering ancient marine environments.
{"title":"Discerning biotic from abiotic carbonate cementations in Holocene beachrock: mineralogical and geochemical fingerprints for biosignatures","authors":"Xi-yang Zhang , Ming-zhuang Wang , Qi Shi , Fei Tan , Guo-tao Zhang , Si-qi Chen , Hong-qiang Yang","doi":"10.1016/j.palaeo.2025.113454","DOIUrl":"10.1016/j.palaeo.2025.113454","url":null,"abstract":"<div><div>Beachrock cementation, mediated by physicochemical and biological processes, plays a pivotal role in the rapid lithification of coastal sediments. Distinguishing between biotic and abiotic carbonate cements is critical for quantitatively reconstructing diagenetic pathways and accurately evaluating paleoenvironmental conditions. We analyzed Holocene beachrocks from Hainan and the Xisha Islands to compare their cement types. Beachrocks from Hainan are characterized by isopachous high-Mg calcite (HMC) rinds, HMC-rich peloidal fabrics, and blocky–drusy low-Mg calcite (LMC), whereas those from the Xisha Islands are dominated by acicular aragonite. HMC rinds composed of equilong fibrous crystals represent marine phreatic cements with minimal diagenetic alteration, whereas LMC forms through meteoric vadose processes, as indicated by red cathodoluminescent rings. Acicular aragonite nucleates within organic-rich micrite envelopes, with its rapid growth governed primarily by inorganic mechanisms. Peloidal fabrics exhibit distinct fluorescence patterns, dull cathodoluminescence, and elevated Mn/Fe ratios, consistent with their interpretation as microbially mediated precipitates formed during organic matter degradation under intermittently reducing conditions. Notably, peloidal fabrics and aragonite are enriched in bioactive metals (V, Fe, Zn, Pb) relative to coral <em>Porites</em>, consistent with active microbial metabolism. Unlike HMC rinds and acicular aragonite, peloidal fabrics display high total rare earth element (REE) contents, uniform REE distributions, LREE depletion (low LREE/HREE), negative Ce anomalies, positive La anomalies, Y/Ho ratios (∼45), and REE partitioning patterns closely matching modern seawater. These distinctive geochemical signatures establish peloidal fabrics as high-fidelity, high-resolution archives of paleo-seawater chemistry, providing a robust tool for deciphering ancient marine environments.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113454"},"PeriodicalIF":2.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753755","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}
Pub Date : 2025-12-11DOI: 10.1016/j.palaeo.2025.113463
Sruthy Rose Baby , Mohan Kuppusamy , Busnur R Manjunatha , Jithin Jose , Pankaj Kumar , Saravanan Kothandaraman , Ravi Mishra
The Arabian Sea sediments have the records of significant temporal and spatial variations in response to the neotectonic changes, paleoclimatic and paleo-sea level fluctuations particularly from the Quaternary period. In this study area, environmental mineral magnetic parameters, diffuse reflectance spectroscopy (DRS), XRF (Fe/K, Ti/Al and Ca %) have been studied in an AMS radiocarbon dated core- SK240/473 from the coast off Saurashtra, south-western part of Gujarat State, north-western continental margin of India, to unravel paleoclimatic and paleoceanographic sedimentation and sea level changes over the past 15 ka BP. Currently, the rainfall of this region mainly occurs during the summer monsoon season. Based on results of multi-proxies measured in this core indicate that three major changes in the climate: phase- I before the Holocene thermal maximum (HTM), phase- II during the HTM, and phase- III after the HTM. The phase-I is mainly characterized by abundance of hematite over goethite with high carbonate content, but lower in total organic carbon (TOC) and chemical weathering index (CWI) suggesting arid climate of oxidizing environment of sediment deposition during the rapid sea level rise from 14.5 ka BP to 12.0 ka BP with a standstill sea level from 12 ka BP - 10 ka BP. In contrast, the phase-II marked by a transition from arid to humid condition of sediment deposition characterized by higher CWI, abundant TOC and goethite, but lower in hematite and carbonate concentrations reflecting humid climate of reducing environment of sediment deposition during the Holocene thermal maximum (HTM) from 10.00 ka BP to 5.50 ka BP. Interpretations made here are generally in good agreement with the deglacial to Holocene Sea level fluctuations curve proposed for the west coast of India. In Phase III, the χlf, χfd, and Chemical Index of Alteration (CIA) data from sediments deposited after the HTM largely suggest deposition in a humid environment, occasionally interrupted by arid episodes in the study region's hinterland. Such arid events linked to paleo-El Niño episodes recorded in the tropical eastern Pacific Ocean. This interpretation is further supported by the reason explained to the current rainfall variability in the hinterland of the study area. Overall, the data of the core studied reveal significant environmental, sea-level and monsoonal changes in the NE Arabian Sea since the deglacial period. The goethite/hematite (G/H) ratio, χlf and χfd profiles which is an indicator of humidity/aridity and coastal upwelling are different from the sea-level curve, suggesting that formers are better indicator of monsoon intensity that often regulated by the ENSO.
阿拉伯海沉积物对新构造变化、古气候和古海平面波动，特别是第四纪以来的变化具有显著的时空变化特征。本研究区对印度西北大陆边缘古吉拉特邦西南部Saurashtra海岸的一个AMS放射性碳定年岩心SK240/473进行了环境矿物磁性参数、漫反射光谱（DRS）和XRF （Fe/K、Ti/Al和Ca %）研究，揭示了过去15 ka BP的古气候和古海洋沉积和海平面变化。目前，该地区的降雨主要发生在夏季季风季节。基于该岩心的多指标测量结果表明，全新世热极大期前的第1阶段、热极大期中的第2阶段和热极大期后的第3阶段是气候变化的主要阶段。第一阶段主要表现为赤铁矿比针铁矿多，碳酸盐含量高，总有机碳（TOC）和化学风化指数（CWI）较低，表明海平面从14.5 ka BP快速上升到12.0 ka BP，海平面从12 ka BP到10 ka BP处于静止状态，处于干燥的氧化沉积环境。全新世热极大值（HTM）从10.00 ka BP降至5.50 ka BP，以CWI较高、TOC和针铁矿丰富、赤铁矿和碳酸盐含量较低为特征的ii期沉积条件由干旱向湿润过渡，反映了沉积环境的湿润气候。这里所做的解释通常与针对印度西海岸提出的从冰期到全新世的海平面波动曲线很好地吻合。在第三阶段，HTM之后沉积的沉积物的χf、χfd和化学蚀变指数（Chemical Index of蚀变，CIA）数据在很大程度上表明沉积在湿润环境中，偶尔会被研究区域腹地的干旱事件打断。这种干旱事件与热带东太平洋记录的古厄尔尼诺Niño事件有关。这一解释进一步得到了对研究区腹地当前降水变率的解释原因的支持。总体而言，所研究的岩心数据揭示了自冰期以来东北阿拉伯海的显著环境、海平面和季风变化。针铁矿/赤铁矿（G/H）比值、χf和χfd曲线与海平面曲线不同，表明针铁矿/赤铁矿（G/H）比、χf和χfd曲线更能反映季风强度，而季风强度通常由ENSO调节。
{"title":"Multi-paleoclimatic proxies implicate climate shift from arid-to-humid in the Northeastern Arabian Sea teleconnected to ENSO events","authors":"Sruthy Rose Baby , Mohan Kuppusamy , Busnur R Manjunatha , Jithin Jose , Pankaj Kumar , Saravanan Kothandaraman , Ravi Mishra","doi":"10.1016/j.palaeo.2025.113463","DOIUrl":"10.1016/j.palaeo.2025.113463","url":null,"abstract":"<div><div>The Arabian Sea sediments have the records of significant temporal and spatial variations in response to the neotectonic changes, paleoclimatic and paleo-sea level fluctuations particularly from the Quaternary period. In this study area, environmental mineral magnetic parameters, diffuse reflectance spectroscopy (DRS), XRF (Fe/K, Ti/Al and Ca %) have been studied in an AMS radiocarbon dated core- SK240/473 from the coast off Saurashtra, south-western part of Gujarat State, north-western continental margin of India, to unravel paleoclimatic and paleoceanographic sedimentation and sea level changes over the past 15 ka BP. Currently, the rainfall of this region mainly occurs during the summer monsoon season. Based on results of multi-proxies measured in this core indicate that three major changes in the climate: phase- I before the Holocene thermal maximum (HTM), phase- II during the HTM, and phase- III after the HTM. The phase-I is mainly characterized by abundance of hematite over goethite with high carbonate content, but lower in total organic carbon (TOC) and chemical weathering index (CWI) suggesting arid climate of oxidizing environment of sediment deposition during the rapid sea level rise from 14.5 ka BP to 12.0 ka BP with a standstill sea level from 12 ka BP - 10 ka BP. In contrast, the phase-II marked by a transition from arid to humid condition of sediment deposition characterized by higher CWI, abundant TOC and goethite, but lower in hematite and carbonate concentrations reflecting humid climate of reducing environment of sediment deposition during the Holocene thermal maximum (HTM) from 10.00 ka BP to 5.50 ka BP. Interpretations made here are generally in good agreement with the deglacial to Holocene Sea level fluctuations curve proposed for the west coast of India. In Phase III, the χlf, χfd, and Chemical Index of Alteration (CIA) data from sediments deposited after the HTM largely suggest deposition in a humid environment, occasionally interrupted by arid episodes in the study region's hinterland. Such arid events linked to paleo-El Niño episodes recorded in the tropical eastern Pacific Ocean. This interpretation is further supported by the reason explained to the current rainfall variability in the hinterland of the study area. Overall, the data of the core studied reveal significant environmental, sea-level and monsoonal changes in the NE Arabian Sea since the deglacial period. The goethite/hematite (G/H) ratio, χlf and χfd profiles which is an indicator of humidity/aridity and coastal upwelling are different from the sea-level curve, suggesting that formers are better indicator of monsoon intensity that often regulated by the ENSO.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113463"},"PeriodicalIF":2.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799353","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}
Pub Date : 2025-12-11DOI: 10.1016/j.palaeo.2025.113491
Shu Chen , Mengmeng Wang , Chunmei Ma , Tianyi Tang , Rui Ke , Jiaming Hou , Xinrong Zhang , Zhuo Zheng , Xiayun Xiao , Yan Zhao , Huayu Lu
Interpreting information documented in fossil pollen provides valuable insights into viewing and dealing with the on-going global change, while linking modern pollen to vegetation and the environment makes paleoenvironmental reconstructions possible. The reliability of quantitative reconstruction depends on the comprehensive understanding of the relationship between the proxy and its determinants, and the applicability of this relationship. Monsoonal China is a forested and densely populated region spanning various climatic and vegetation zones. Fossil pollen sequences from peatlands of monsoonal China are frequently studied, but the assumptions ensuring a reliable reconstruction remained untested. In this study, we compiled 56 peatland surface pollen assemblages, compared them to the neighboring soil surface pollen assemblage and vegetation composition data, and examined the response of our peatland surface pollen assemblages to environmental variables. Through quantitative analysis, we confirmed the representation of pollen for vegetation at both compositional and vegetational level, and demonstrated the taphonomic effect with differences in pollen composition and vegetation representation between two sediment types. Peatland surface pollen shows higher diversity, higher non-arboreal pollen abundance, lower arboreal pollen abundance and higher vegetation representative power than soil surface pollen because of a larger pollen source area. Climate sets the foundation in modern pollen assemblages across monsoonal China. However, in subregions, an abnormal positive correlation between herbaceous pollen and temperature suggests the incorporation of human influence into this correlation. Therefore, reconsideration of the ecological nature of correlations is needed for improving the reliability of climate reconstruction.
{"title":"Modern pollen analysis on peatlands across monsoonal China and its implications for reconstruction","authors":"Shu Chen , Mengmeng Wang , Chunmei Ma , Tianyi Tang , Rui Ke , Jiaming Hou , Xinrong Zhang , Zhuo Zheng , Xiayun Xiao , Yan Zhao , Huayu Lu","doi":"10.1016/j.palaeo.2025.113491","DOIUrl":"10.1016/j.palaeo.2025.113491","url":null,"abstract":"<div><div>Interpreting information documented in fossil pollen provides valuable insights into viewing and dealing with the on-going global change, while linking modern pollen to vegetation and the environment makes paleoenvironmental reconstructions possible. The reliability of quantitative reconstruction depends on the comprehensive understanding of the relationship between the proxy and its determinants, and the applicability of this relationship. Monsoonal China is a forested and densely populated region spanning various climatic and vegetation zones. Fossil pollen sequences from peatlands of monsoonal China are frequently studied, but the assumptions ensuring a reliable reconstruction remained untested. In this study, we compiled 56 peatland surface pollen assemblages, compared them to the neighboring soil surface pollen assemblage and vegetation composition data, and examined the response of our peatland surface pollen assemblages to environmental variables. Through quantitative analysis, we confirmed the representation of pollen for vegetation at both compositional and vegetational level, and demonstrated the taphonomic effect with differences in pollen composition and vegetation representation between two sediment types. Peatland surface pollen shows higher diversity, higher non-arboreal pollen abundance, lower arboreal pollen abundance and higher vegetation representative power than soil surface pollen because of a larger pollen source area. Climate sets the foundation in modern pollen assemblages across monsoonal China. However, in subregions, an abnormal positive correlation between herbaceous pollen and temperature suggests the incorporation of human influence into this correlation. Therefore, reconsideration of the ecological nature of correlations is needed for improving the reliability of climate reconstruction.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"683 ","pages":"Article 113491"},"PeriodicalIF":2.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787959","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}
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