Pub Date : 2025-02-20DOI: 10.1016/j.palaeo.2025.112836
Wentai Liu , Qiang Li , Qiufang Cai , Huiming Song , Changfeng Sun , Piotr Owczarek , Meng Ren , Yifan Ma , Xiangyu Duan , Olga Solomina , Vladimir Matskovsky , Yu Liu
Since the late 20th century, global warming has resulted in the significant retreat of alpine glaciers in high-altitude mountainous regions worldwide. However, the glaciers in the Karakoram Mountains of Central Asia have remained stable or even expanded over recent decades, a phenomenon termed the “Karakoram Anomaly”. Here, we use tree-ring width of Picea schrenkiana growing at high altitudes of the Karakoram Mountains, to reconstruct summer (June–August) temperature variations since 1851 (r = 0.66, n = 62, p < 0.001), and to investigate the climatic context of the “Karakoram anomaly”. Comparative analysis with nearby tree-ring studies, glacier mass balance series in Central Asia, and Northern Hemispheric temperature reconstructions reveals a significant divergence in summer temperature trends in the Karakoram Mountains after the 1980s, corresponding to anomalous glacier behavior. The combination of increased precipitation, reduced summer temperatures, and specific glacier conditions in the Karakoram region has created a unique set of natural conditions that diverge from global trends. Our findings provide further evidence supporting the existence of the “Karakoram Anomaly” under global climate change.
{"title":"Recent cooling enhances glacier resilience to global warming in the northern Karakoram: Evidence from tree rings","authors":"Wentai Liu , Qiang Li , Qiufang Cai , Huiming Song , Changfeng Sun , Piotr Owczarek , Meng Ren , Yifan Ma , Xiangyu Duan , Olga Solomina , Vladimir Matskovsky , Yu Liu","doi":"10.1016/j.palaeo.2025.112836","DOIUrl":"10.1016/j.palaeo.2025.112836","url":null,"abstract":"<div><div>Since the late 20th century, global warming has resulted in the significant retreat of alpine glaciers in high-altitude mountainous regions worldwide. However, the glaciers in the Karakoram Mountains of Central Asia have remained stable or even expanded over recent decades, a phenomenon termed the “Karakoram Anomaly”. Here, we use tree-ring width of <em>Picea schrenkiana</em> growing at high altitudes of the Karakoram Mountains, to reconstruct summer (June–August) temperature variations since 1851 (<em>r</em> = 0.66, <em>n</em> = 62, <em>p</em> < 0.001), and to investigate the climatic context of the “Karakoram anomaly”. Comparative analysis with nearby tree-ring studies, glacier mass balance series in Central Asia, and Northern Hemispheric temperature reconstructions reveals a significant divergence in summer temperature trends in the Karakoram Mountains after the 1980s, corresponding to anomalous glacier behavior. The combination of increased precipitation, reduced summer temperatures, and specific glacier conditions in the Karakoram region has created a unique set of natural conditions that diverge from global trends. Our findings provide further evidence supporting the existence of the “Karakoram Anomaly” under global climate change.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112836"},"PeriodicalIF":2.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487937","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 : 2025-02-19DOI: 10.1016/j.palaeo.2025.112829
Susana Rodríguez-Franco , Víctor Adrián Pérez-Crespo , Christina I. Barrón-Ortiz , Luis Córdoba-Barradas , Joaquín Arroyo-Cabrales , Florent Rivals , Edith Cienfuegos-Alvarado , Francisco J. Otero , Alan U. Loredo-Jasso , Laura Eugenia Beramendi-Orosco
Using carbon and oxygen isotopic values from tooth enamel, as well as carbon and nitrogen from collagen and, dental microwear analysis, the diet and other paleobiological characteristics of 11 specimens of Mammuthus columbi from the Tultepec I and Tultpec II deposits, Estado de México, México, were inferred; additionally, three mandible bones were radiocarbon dated (13,170–13,450 cal BP). The results of carbon isotope analyses of enamel and collagen reveal that 10 individuals had a mixed C3/C4 diet and only one showed δ13C values indicative of a C3 plant-based diet. Similar results were obtained from the analysis of dental microwear, where most individuals were identified as mixed feeders and only one as a browser.
The results of the different proxies suggest that some individuals modified their dietary habits during their lifetime while others maintained them. In the case of δ18O values, these show that perhaps the Tultepec population was composed of local individuals and migrants from other localities. The variations observed among the δ15N values of the individuals studied are possibly influenced by milk intake, as well as the consumption of nitrogen-fixing plants and hydric stress.
{"title":"Dietary reconstruction of Mammuthus columbi from Tultepec, Estado de México, México: A multiproxy approach","authors":"Susana Rodríguez-Franco , Víctor Adrián Pérez-Crespo , Christina I. Barrón-Ortiz , Luis Córdoba-Barradas , Joaquín Arroyo-Cabrales , Florent Rivals , Edith Cienfuegos-Alvarado , Francisco J. Otero , Alan U. Loredo-Jasso , Laura Eugenia Beramendi-Orosco","doi":"10.1016/j.palaeo.2025.112829","DOIUrl":"10.1016/j.palaeo.2025.112829","url":null,"abstract":"<div><div>Using carbon and oxygen isotopic values from tooth enamel, as well as carbon and nitrogen from collagen and, dental microwear analysis, the diet and other paleobiological characteristics of 11 specimens of <em>Mammuthus columbi</em> from the Tultepec I and Tultpec II deposits, Estado de México, México, were inferred; additionally, three mandible bones were radiocarbon dated (13,170–13,450 cal BP). The results of carbon isotope analyses of enamel and collagen reveal that 10 individuals had a mixed C<sub>3</sub>/C<sub>4</sub> diet and only one showed δ<sup>13</sup>C values indicative of a C<sub>3</sub> plant-based diet. Similar results were obtained from the analysis of dental microwear, where most individuals were identified as mixed feeders and only one as a browser.</div><div>The results of the different proxies suggest that some individuals modified their dietary habits during their lifetime while others maintained them. In the case of δ<sup>18</sup>O values, these show that perhaps the Tultepec population was composed of local individuals and migrants from other localities. The variations observed among the δ<sup>15</sup>N values of the individuals studied are possibly influenced by milk intake, as well as the consumption of nitrogen-fixing plants and hydric stress.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112829"},"PeriodicalIF":2.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519917","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 : 2025-02-19DOI: 10.1016/j.palaeo.2025.112832
Jason R. Ali , Yong-Xiang Li , Uwe Fritz
A radical vicariance-biogeographical theory was proposed in 2016 to account for some of the plant taxa on China's Hainan Island. It involves the landmass undergoing significant changes in its position relative to mainland southern China between the Late Cretaceous and the present. This ‘shifting-landmass’ hypothesis has since been widely adopted and is now invoked to explain the occurrence of 17 faunal and multiple floral components (based on 14 published studies). In this paper, we review geological and biological evidence that falsify this conjecture. First, Hainan shifted no more than c. 47 km to the SE, through extension and strike-slip faulting within the Beibu Gulf Basin, principally in the Late Eocene through Oligocene. Second, our biological appraisal, using data for the claimed supportive clades plus the island's 41 amphibian and 48 land-bound mammal groups (such taxa are poor over-water dispersers and should thus inform tests of the vicariance hypothesis), offers minimal backing. Just three lineages (Goniurosaurus geckos, pheretimoid earthworms and Stedocys spitting spiders) have ‘colonization intervals’ that overlap the 70–23 Mya window that is associated with the hypothesis, as well as being sourced from Vietnam-Guangxi (the proposal's second element). Of the remaining 90 clades that have establishment ages, all but one arrived after 6.5 Mya with most since 2 Mya. The geological evidence indicates that throughout the Cenozoic, Hainan never really functioned as an island due to the frequent eustatic falls, which when combined with the surrounding shallow seabed resulted in the landmass regularly merging with Indochina and mainland southern China. This explains the preponderance of young clades, many of which are non-endemic. Furthermore, there is no obvious preference to the taxa's geographical origins, that is, tropical Indochina or temperate southern China; most are classified as ‘of indeterminate biogeographical origin’.
{"title":"Biogeography of Hainan Island, southern China, and the falsification of the ‘shifting-landmass’ hypothesis","authors":"Jason R. Ali , Yong-Xiang Li , Uwe Fritz","doi":"10.1016/j.palaeo.2025.112832","DOIUrl":"10.1016/j.palaeo.2025.112832","url":null,"abstract":"<div><div>A radical vicariance-biogeographical theory was proposed in 2016 to account for some of the plant taxa on China's Hainan Island. It involves the landmass undergoing significant changes in its position relative to mainland southern China between the Late Cretaceous and the present. This ‘shifting-landmass’ hypothesis has since been widely adopted and is now invoked to explain the occurrence of 17 faunal and multiple floral components (based on 14 published studies). In this paper, we review geological and biological evidence that falsify this conjecture. First, Hainan shifted no more than <em>c</em>. 47 km to the SE, through extension and strike-slip faulting within the Beibu Gulf Basin, principally in the Late Eocene through Oligocene. Second, our biological appraisal, using data for the claimed supportive clades plus the island's 41 amphibian and 48 land-bound mammal groups (such taxa are poor over-water dispersers and should thus inform tests of the vicariance hypothesis), offers minimal backing. Just three lineages (<em>Goniurosaurus</em> geckos, pheretimoid earthworms and <em>Stedocys</em> spitting spiders) have ‘colonization intervals’ that overlap the 70–23 Mya window that is associated with the hypothesis, as well as being sourced from Vietnam-Guangxi (the proposal's second element). Of the remaining 90 clades that have establishment ages, all but one arrived after 6.5 Mya with most since 2 Mya. The geological evidence indicates that throughout the Cenozoic, Hainan never really functioned as an island due to the frequent eustatic falls, which when combined with the surrounding shallow seabed resulted in the landmass regularly merging with Indochina and mainland southern China. This explains the preponderance of young clades, many of which are non-endemic. Furthermore, there is no obvious preference to the taxa's geographical origins, that is, tropical Indochina or temperate southern China; most are classified as ‘of indeterminate biogeographical origin’.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112832"},"PeriodicalIF":2.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550488","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}
Pub Date : 2025-02-19DOI: 10.1016/j.palaeo.2025.112817
Zhihai Tan , Qi Zhang , Yongming M Han , Longjiang Mao , Shuxin Zheng , Meng Wang , Huanrong Zuo , Hanmiao Qin
Resolving the complex interplay between natural and anthropogenic fire drivers remains a critical challenge in paleoenvironmental studies. This investigation employs an innovative multi-proxy approach integrating fecal stanol biomarkers with high-resolution records of charcoal and black carbon to reconstruct Holocene biomass burning dynamics and human-environment interactions at two key prehistoric profiles: the Yangguancun (YGC) loess profile (Shaanxi Province, the middle reaches of the Yellow River Drainage Basin) and Changyi (CY) terrestrial sequence (Shandong Province, the lower reaches of the Yellow River Basin). Our analysis reveals three distinct fire regime phases across the basin: 1) Early Holocene monsoon-controlled infrequent wildfires (8700–8500 yr BP), 2) Mid-late Holocene localized anthropogenic high biomass burning (6000–1000 yr BP), and 3) Recent millennium-scale regional anthropogenic combustion dominance. Between 6200 and 5300 yr BP, high-intensity biomass burning in the middle reaches of the Yellow River was primarily driven by frequent slash-and-burn practices for forest clearance for millet cultivation and daily subsistence activities during the late Miaodigou and Banpo IV Cultures. Contrastingly, between 4000 and 3500 yr BP, low-intensity smoldering fires in the lower reaches of the Yellow River were associated with persistent aridity and deforestation during the Longshan and Yueshi Cultures. These contrasting fire regimes reflect the complex interplay between monsoon-driven climate variability and anthropogenic land-use practices, leading to significant landscape changes in the region during the mid-to-late Holocene. Meanwhile, the region underwent a vegetation evolution, transitioning from fire-resilient natural forests and grasslands to fire-prone secondary shrub lands and cultivated lands. It was noted that long-term deforestation and vegetation fragmentation, exacerbated by persistent drought, has triggered smoldering biomass burning pattern, which have become a primary driver of future wildfires and vegetation degradation in the middle and lower reaches of the Yellow River. Combining fecal stanol molecular biomarkers with sedimentary charcoal and black carbon records, we clarify the distinctions between natural and human-induced fires, providing a deeper understanding of the impact of anthropogenic biomass burning on regional and global warming.
{"title":"Coprostanol records from two distinct prehistoric profiles in the middle and lower reaches of the Yellow River, China, provide evidence of anthropogenic fires","authors":"Zhihai Tan , Qi Zhang , Yongming M Han , Longjiang Mao , Shuxin Zheng , Meng Wang , Huanrong Zuo , Hanmiao Qin","doi":"10.1016/j.palaeo.2025.112817","DOIUrl":"10.1016/j.palaeo.2025.112817","url":null,"abstract":"<div><div>Resolving the complex interplay between natural and anthropogenic fire drivers remains a critical challenge in paleoenvironmental studies. This investigation employs an innovative multi-proxy approach integrating fecal stanol biomarkers with high-resolution records of charcoal and black carbon to reconstruct Holocene biomass burning dynamics and human-environment interactions at two key prehistoric profiles: the Yangguancun (YGC) loess profile (Shaanxi Province, the middle reaches of the Yellow River Drainage Basin) and Changyi (CY) terrestrial sequence (Shandong Province, the lower reaches of the Yellow River Basin). Our analysis reveals three distinct fire regime phases across the basin: 1) Early Holocene monsoon-controlled infrequent wildfires (8700–8500 yr BP), 2) Mid-late Holocene localized anthropogenic high biomass burning (6000–1000 yr BP), and 3) Recent millennium-scale regional anthropogenic combustion dominance. Between 6200 and 5300 yr BP, high-intensity biomass burning in the middle reaches of the Yellow River was primarily driven by frequent slash-and-burn practices for forest clearance for millet cultivation and daily subsistence activities during the late Miaodigou and Banpo IV Cultures. Contrastingly, between 4000 and 3500 yr BP, low-intensity smoldering fires in the lower reaches of the Yellow River were associated with persistent aridity and deforestation during the Longshan and Yueshi Cultures. These contrasting fire regimes reflect the complex interplay between monsoon-driven climate variability and anthropogenic land-use practices, leading to significant landscape changes in the region during the mid-to-late Holocene. Meanwhile, the region underwent a vegetation evolution, transitioning from fire-resilient natural forests and grasslands to fire-prone secondary shrub lands and cultivated lands. It was noted that long-term deforestation and vegetation fragmentation, exacerbated by persistent drought, has triggered smoldering biomass burning pattern, which have become a primary driver of future wildfires and vegetation degradation in the middle and lower reaches of the Yellow River. Combining fecal stanol molecular biomarkers with sedimentary charcoal and black carbon records, we clarify the distinctions between natural and human-induced fires, providing a deeper understanding of the impact of anthropogenic biomass burning on regional and global warming.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112817"},"PeriodicalIF":2.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487931","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 : 2025-02-19DOI: 10.1016/j.palaeo.2025.112831
Hua-Yan Li , Yao Wu , Ting-Yong Li , Rong Duan , Hai-Bo Wang , Jia-Hui Cui , Chao-Jun Chen , Yue Jin , Yue-Hua Xiang , Zi-Qi Liu , Jun-Yun Li
Speleothem δ18O, δ13C, growth rate, Mg/Ca and Sr/Ca record varying environmental information due to their different influencing factors. Multiproxy analysis provides a deeper, multiangled interpretation of the palaeoclimate information recorded in speleothems. This work analyses the environmental information recorded by the δ18O, δ13C, growth rate, Mg/Ca and Sr/Ca ratios of multiple stalagmites, and other proxies of lake sediments in Southwest China during the mid-to-late Holocene. The results indicate that (1) the δ18O and δ13C values of stalagmite FL2 showed a gradually positive trend and were consistent with the decreasing pattern of precipitation affected by the Asian summer monsoon during 6.2–0.69 ka BP. (2) In the three periods of 6.2–4.2, 4.2–2.2 and 2.2–0.69 ka BP, the δ18O and δ13C values of stalagmite FL2 showed positive–negative–positive trends, respectively. Accordingly, the Mg/Ca ratios showed an increasing–decreasing–increasing trend, corresponding to the decreasing–increasing–decreasing variation characteristics of precipitation. The growth rate was sensitive to the increased precipitation from 4.2 to 2.2 ka BP. (3) The δ18O and δ13C values changed positively, and the Mg/Ca and Sr/Ca ratios increased when extreme climate events occurred (e.g. 5.5, 4.2, 2.8 and 1.0 ka event) in the mid-to-late Holocene. The multiple geochemical proxies of stalagmite FL2 corresponded well with the records in other stalagmites and lake sediments in Southwest China. (4) Principal component analysis (PCA) and power spectral analysis reveal that the δ18O values of stalagmite FL2 mainly respond to the changes in the Asian summer monsoon intensity at decadal to centennial scales and even longer. The δ13C values and Mg/Ca and Sr/Ca ratios mainly reflect decadal and multidecadal variability in regional precipitation.
{"title":"Variation in climate and hydrological conditions in Southwest China during the mid-to-late Holocene, inferred from stalagmite multiple proxies","authors":"Hua-Yan Li , Yao Wu , Ting-Yong Li , Rong Duan , Hai-Bo Wang , Jia-Hui Cui , Chao-Jun Chen , Yue Jin , Yue-Hua Xiang , Zi-Qi Liu , Jun-Yun Li","doi":"10.1016/j.palaeo.2025.112831","DOIUrl":"10.1016/j.palaeo.2025.112831","url":null,"abstract":"<div><div>Speleothem δ<sup>18</sup>O, δ<sup>13</sup>C, growth rate, Mg/Ca and Sr/Ca record varying environmental information due to their different influencing factors. Multiproxy analysis provides a deeper, multiangled interpretation of the palaeoclimate information recorded in speleothems. This work analyses the environmental information recorded by the δ<sup>18</sup>O, δ<sup>13</sup>C, growth rate, Mg/Ca and Sr/Ca ratios of multiple stalagmites, and other proxies of lake sediments in Southwest China during the mid-to-late Holocene. The results indicate that (1) the δ<sup>18</sup>O and δ<sup>13</sup>C values of stalagmite FL2 showed a gradually positive trend and were consistent with the decreasing pattern of precipitation affected by the Asian summer monsoon during 6.2–0.69 ka BP. (2) In the three periods of 6.2–4.2, 4.2–2.2 and 2.2–0.69 ka BP, the δ<sup>18</sup>O and δ<sup>13</sup>C values of stalagmite FL2 showed positive–negative–positive trends, respectively. Accordingly, the Mg/Ca ratios showed an increasing–decreasing–increasing trend, corresponding to the decreasing–increasing–decreasing variation characteristics of precipitation. The growth rate was sensitive to the increased precipitation from 4.2 to 2.2 ka BP. (3) The δ<sup>18</sup>O and δ<sup>13</sup>C values changed positively, and the Mg/Ca and Sr/Ca ratios increased when extreme climate events occurred (e.g. 5.5, 4.2, 2.8 and 1.0 ka event) in the mid-to-late Holocene. The multiple geochemical proxies of stalagmite FL2 corresponded well with the records in other stalagmites and lake sediments in Southwest China. (4) Principal component analysis (PCA) and power spectral analysis reveal that the δ<sup>18</sup>O values of stalagmite FL2 mainly respond to the changes in the Asian summer monsoon intensity at decadal to centennial scales and even longer. The δ<sup>13</sup>C values and Mg/Ca and Sr/Ca ratios mainly reflect decadal and multidecadal variability in regional precipitation.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112831"},"PeriodicalIF":2.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510454","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 : 2025-02-18DOI: 10.1016/j.palaeo.2025.112820
Andrea Baucon , Marco Avanzini , Carlos Neto de Carvalho , Zain Belaústegui , Nereo Preto , Anna Breda
A new exceptionally exposed ichnofauna is reported from the Upper Triassic Travenanzes Formation of Braies in the Dolomites (Italy). The ichnosite is extraordinary in that it provides a continuous exposure of 32,000 m2 of intensely bioturbated dolostone. The bioturbated surface is characterized by vertical burrows (Psilonichnus upsilon) occurring at a density of 5 openings / m2. With more than 160,000 burrow openings, the Braies ichnosite preserves the largest exposure ever described for Psilonichnus. The Psilonichnus-bearing horizons represent a carbonate tidal flat that bordered an arid coastal plain, as evidenced by facies analysis and confirmed by the presence of Taenidium barretti. Comparison with modern ocypodid burrows indicates that the Psilonichnus from Braies are compatible with a crab tracemaker (Decapoda: Brachyura), which would represent the earliest fossil evidence for true crabs, although other arthropods cannot be fully discounted as the producers.
{"title":"The earliest evidence of true crabs? Insights on the evolution of Brachyura from an exceptional exposure of Carnian Psilonichnus (Upper Triassic, Braies, Dolomites, Italy)","authors":"Andrea Baucon , Marco Avanzini , Carlos Neto de Carvalho , Zain Belaústegui , Nereo Preto , Anna Breda","doi":"10.1016/j.palaeo.2025.112820","DOIUrl":"10.1016/j.palaeo.2025.112820","url":null,"abstract":"<div><div>A new exceptionally exposed ichnofauna is reported from the Upper Triassic Travenanzes Formation of Braies in the Dolomites (Italy). The ichnosite is extraordinary in that it provides a continuous exposure of 32,000 m<sup>2</sup> of intensely bioturbated dolostone. The bioturbated surface is characterized by vertical burrows (<em>Psilonichnus upsilon</em>) occurring at a density of 5 openings / m<sup>2</sup>. With more than 160,000 burrow openings, the Braies ichnosite preserves the largest exposure ever described for <em>Psilonichnus</em>. The <em>Psilonichnus-</em>bearing horizons represent a carbonate tidal flat that bordered an arid coastal plain, as evidenced by facies analysis and confirmed by the presence of <em>Taenidium barretti.</em> Comparison with modern ocypodid burrows indicates that the <em>Psilonichnus</em> from Braies are compatible with a crab tracemaker (Decapoda: Brachyura), which would represent the earliest fossil evidence for true crabs, although other arthropods cannot be fully discounted as the producers.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112820"},"PeriodicalIF":2.6,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562228","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 : 2025-02-18DOI: 10.1016/j.palaeo.2025.112808
Xiqian Wang , Liangcheng Tan , Ashish Sinha , Hai Xu , Haiwei Zhang , Jianghu Lan , Jin Zhang , Tianli Wang , Dong Li , Le Ma , Jingjie Zang , Xing Cheng , Yanzhen Li , Huiru Tang , Xu Lin , R. Lawrence Edwards , Hai Cheng
The Younger Dryas (YD) was a large-scale abrupt climate event during the last deglaciation with wide-ranging effects on the global environment. Here, we present an absolute dated speleothem oxygen isotope record (δ18O) of Indian Summer Monsoon (ISM) variability from Shenqi Cave in the southeastern Tibetan Plateau (TP) across the YD event. The δ18O of SQ8 increased markedly by ∼4 ‰ during the YD, which is substantially larger than other coeval stalagmite δ18O records from the East Asian and Indian monsoon regions. This distinct increase may be ascribed to the combined influences of the altitude effect and the diminished transpiration from vegetation. Our data indicate an abrupt increase in ISM strength occurred in tandem with the termination of the Younger Dryas (∼76 years). The ISM's rapid response to the YD event may be due to the TP's location upstream of Rossby waves, as well as the enhanced feedback caused by the surface ice and snow cover. Our data further indicate that multidecadal variations in ISM intensity are positively correlated with the Atlantic Multidecadal Oscillation (AMO) amplitude, modulated by long-term solar radiation and sea ice changes.
{"title":"Rapid Indian Monsoon response to the Younger Dryas event in the Southeastern Tibetan Plateau","authors":"Xiqian Wang , Liangcheng Tan , Ashish Sinha , Hai Xu , Haiwei Zhang , Jianghu Lan , Jin Zhang , Tianli Wang , Dong Li , Le Ma , Jingjie Zang , Xing Cheng , Yanzhen Li , Huiru Tang , Xu Lin , R. Lawrence Edwards , Hai Cheng","doi":"10.1016/j.palaeo.2025.112808","DOIUrl":"10.1016/j.palaeo.2025.112808","url":null,"abstract":"<div><div>The Younger Dryas (YD) was a large-scale abrupt climate event during the last deglaciation with wide-ranging effects on the global environment. Here, we present an absolute dated speleothem oxygen isotope record (δ<sup>18</sup>O) of Indian Summer Monsoon (ISM) variability from Shenqi Cave in the southeastern Tibetan Plateau (TP) across the YD event. The δ<sup>18</sup>O of SQ8 increased markedly by ∼4 ‰ during the YD, which is substantially larger than other coeval stalagmite δ<sup>18</sup>O records from the East Asian and Indian monsoon regions. This distinct increase may be ascribed to the combined influences of the altitude effect and the diminished transpiration from vegetation. Our data indicate an abrupt increase in ISM strength occurred in tandem with the termination of the Younger Dryas (∼76 years). The ISM's rapid response to the YD event may be due to the TP's location upstream of Rossby waves, as well as the enhanced feedback caused by the surface ice and snow cover. Our data further indicate that multidecadal variations in ISM intensity are positively correlated with the Atlantic Multidecadal Oscillation (AMO) amplitude, modulated by long-term solar radiation and sea ice changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"665 ","pages":"Article 112808"},"PeriodicalIF":2.6,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474437","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 : 2025-02-17DOI: 10.1016/j.palaeo.2025.112815
Yaping Li , Wenhao Zheng , Wenfei Liu , Kai Su , Wei Liu , Junna Zhang , Kai Ning , Zhenjing Yang , Guiyun Jin
Pollen serves as a critical proxy for quantitative paleoclimatic reconstruction, with high-quality modern pollen databases and advanced modeling approaches significantly enhancing the reliability of reconstructed climatic parameters and providing multifaceted insights into past climate dynamics. This study presents a quantitative paleoclimatic reconstruction based on pollen analysis from the Dingjiazhuang profile in northern Shandong, China. The LWWA (inverse) model at 900 km was identified as the optimal model for climatic parameter reconstruction. Our results delineate periodic changes of Mid- to Late Holocene climate in the study area through reconstructed curves of annual precipitation (Pann), mean precipitation of the warmest month (MPwa), mean temperature of the warmest month (MTwa), and mean temperature of the coldest month (MTco) spanning 8–2.6 ka. Five distinct climatic phases were identified: A cool-dry fluctuation phase (8.1–6.8 ka), a warm-humid Mid-Holocene Climatic Optimum (6.8–6.2 ka), a transitional cool-humid phase (6.2–5.3 ka), a warm-dry phase (5.3–3.1 ka), and a cool-dry phase (3.1–2.6 ka). Millennial-scale variations were predominantly driven by the interplay between the East Asian Summer Monsoon (EASM) and East Asian Winter Monsoon (EAWM). Centennial-scale anomalies include 8.2 ka, 5.5 ka, and 4.2 ka events. The complex forcing mechanisms underlying these events warrant further investigation. This study represents the first attempt to establish climate quantification in northern Shandong, providing critical data support for understanding the environmental evolution of the East Asian monsoon region during the Holocene.
{"title":"Quantitative climate reconstruction of the Mid- to late Holocene based on pollen records from Northern Shandong, China","authors":"Yaping Li , Wenhao Zheng , Wenfei Liu , Kai Su , Wei Liu , Junna Zhang , Kai Ning , Zhenjing Yang , Guiyun Jin","doi":"10.1016/j.palaeo.2025.112815","DOIUrl":"10.1016/j.palaeo.2025.112815","url":null,"abstract":"<div><div>Pollen serves as a critical proxy for quantitative paleoclimatic reconstruction, with high-quality modern pollen databases and advanced modeling approaches significantly enhancing the reliability of reconstructed climatic parameters and providing multifaceted insights into past climate dynamics. This study presents a quantitative paleoclimatic reconstruction based on pollen analysis from the Dingjiazhuang profile in northern Shandong, China. The LWWA (inverse) model at 900 km was identified as the optimal model for climatic parameter reconstruction. Our results delineate periodic changes of Mid- to Late Holocene climate in the study area through reconstructed curves of annual precipitation (Pann), mean precipitation of the warmest month (MPwa), mean temperature of the warmest month (MTwa), and mean temperature of the coldest month (MTco) spanning 8–2.6 ka. Five distinct climatic phases were identified: A cool-dry fluctuation phase (8.1–6.8 ka), a warm-humid Mid-Holocene Climatic Optimum (6.8–6.2 ka), a transitional cool-humid phase (6.2–5.3 ka), a warm-dry phase (5.3–3.1 ka), and a cool-dry phase (3.1–2.6 ka). Millennial-scale variations were predominantly driven by the interplay between the East Asian Summer Monsoon (EASM) and East Asian Winter Monsoon (EAWM). Centennial-scale anomalies include 8.2 ka, 5.5 ka, and 4.2 ka events. The complex forcing mechanisms underlying these events warrant further investigation. This study represents the first attempt to establish climate quantification in northern Shandong, providing critical data support for understanding the environmental evolution of the East Asian monsoon region during the Holocene.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"665 ","pages":"Article 112815"},"PeriodicalIF":2.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454872","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 : 2025-02-17DOI: 10.1016/j.palaeo.2025.112821
Chuan Guo , Yong Fu , Peng Xia , Zhen Yang , Yanjun Li , Zhongfei Pan
The phosphorites of the Lower Cambrian Gezhongwu Formation on the Yangtze Block of South China (specially Zhijin area of Guizhou province) yield exceptionally high rare earth elements (REE) contents up to 1700 ppm, which could serve a potential source of REE industry. The tectonic setting and paleoenvironment of the REE enrichment of the Gezhongwu phosphorites and the REE source in these phosphorites, however, remain poorly constrained. This study conducts a comprehensive analysis of lithology and bulk-rock major and trace elements (including REE) on the Ediacaran-Cambrian (E-C) successions of three sections (Gezhongwu, Zhalagou and Jiebeidong) in different depositional settings of the upper-middle Yangtze areas, in order to elucidate the tectonic setting, paleoenvironment and the REE source of the Gezhongwu phosphorites in the Zhijin area of Guizhou province. The Post-Archean Australian Shale (PAAS, subscript N)-normalized REE patterns of the E-C intervals in the study area exhibit seawater-like signatures (e.g., minor LREE depletion, HREE enrichment and positive La anomalies). In addition, the E-C successions in certain sections share positive Eu anomalies ([Eu/Eu*]N) of varying degrees (e.g., Zhalagou) and relatively low Y/Ho ratios (average 30; Zhalagou and Jiebeidong sections), suggesting the variable contributions of high-temperature hydrothermal fluids during the E-C period. Additionally, the negative Ce anomalies ([Ce/Ce*]N) with a wide range (0.32–0.87) of the E-C strata and the reported redox fluctuations in the South China indicate fluctuating oxygenation conditions across different depositional settings and high redox heterogeneity. The lack of correlation between total REE contents (ƩREE) and Zr and Th of the Gezhongwu phosphorites in the Zhijin area implies a minimal contribution of terrestrial sources. Considering the tectonic setting and the REE profiles of the Gezhongwu phosphorites in the Zhijin area, it is hypothesized that a mixture of seawater and varying amounts (0.1 % ∼ 1 %) of high-temperature hydrothermal fluids is likely the primary source for the REE enrichment of the Gezhongwu phosphorites, and high-temperature hydrothermal fluids might contribute a significant, yet potentially underestimated, quantities of REE. This study offers valuable insights into understanding the tectonic setting and paleoenvironment of REE enrichment in phosphorites and their sources in the geological records.
{"title":"Tectonic setting, paleoenvironment and REE source of the Lower Cambrian phosphorites, Yangtze Block (South China)","authors":"Chuan Guo , Yong Fu , Peng Xia , Zhen Yang , Yanjun Li , Zhongfei Pan","doi":"10.1016/j.palaeo.2025.112821","DOIUrl":"10.1016/j.palaeo.2025.112821","url":null,"abstract":"<div><div>The phosphorites of the Lower Cambrian Gezhongwu Formation on the Yangtze Block of South China (specially Zhijin area of Guizhou province) yield exceptionally high rare earth elements (REE) contents up to 1700 ppm, which could serve a potential source of REE industry. The tectonic setting and paleoenvironment of the REE enrichment of the Gezhongwu phosphorites and the REE source in these phosphorites, however, remain poorly constrained. This study conducts a comprehensive analysis of lithology and bulk-rock major and trace elements (including REE) on the Ediacaran-Cambrian (<em>E</em>-C) successions of three sections (Gezhongwu, Zhalagou and Jiebeidong) in different depositional settings of the upper-middle Yangtze areas, in order to elucidate the tectonic setting, paleoenvironment and the REE source of the Gezhongwu phosphorites in the Zhijin area of Guizhou province. The Post-Archean Australian Shale (PAAS, subscript N)-normalized REE patterns of the <em>E</em>-C intervals in the study area exhibit seawater-like signatures (e.g., minor LREE depletion, HREE enrichment and positive La anomalies). In addition, the <em>E</em>-C successions in certain sections share positive Eu anomalies ([Eu/Eu*]<sub>N</sub>) of varying degrees (e.g., Zhalagou) and relatively low Y/Ho ratios (average 30; Zhalagou and Jiebeidong sections), suggesting the variable contributions of high-temperature hydrothermal fluids during the <em>E</em>-C period. Additionally, the negative Ce anomalies ([Ce/Ce*]<sub>N</sub>) with a wide range (0.32–0.87) of the E-C strata and the reported redox fluctuations in the South China indicate fluctuating oxygenation conditions across different depositional settings and high redox heterogeneity. The lack of correlation between total REE contents (ƩREE) and Zr and Th of the Gezhongwu phosphorites in the Zhijin area implies a minimal contribution of terrestrial sources. Considering the tectonic setting and the REE profiles of the Gezhongwu phosphorites in the Zhijin area, it is hypothesized that a mixture of seawater and varying amounts (0.1 % ∼ 1 %) of high-temperature hydrothermal fluids is likely the primary source for the REE enrichment of the Gezhongwu phosphorites, and high-temperature hydrothermal fluids might contribute a significant, yet potentially underestimated, quantities of REE. This study offers valuable insights into understanding the tectonic setting and paleoenvironment of REE enrichment in phosphorites and their sources in the geological records.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"665 ","pages":"Article 112821"},"PeriodicalIF":2.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445453","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 : 2025-02-17DOI: 10.1016/j.palaeo.2025.112819
Tara A. Putri , Benjamin C. Gill , Stephen E. Scheckler , Rachel Reid
The evolutionary emergence of the CAM (Crassulacean Acid Metabolism) photosynthetic pathway is unknown, but some studies have speculated it may have emerged during the Devonian-Carboniferous when vascular plants first proliferated in terrestrial environments. Specifically, some Carboniferous arborescent lycopsids (e.g., Lepidodendropsis) have morphological features similar to modern CAM plants. In this study, we systematically examine the carbon isotope compositions of an assemblage of Tournaisian (Mississippian) Lepidodendropsis for evidence of alternative photosynthetic pathways. Previous work suggests that the CAM pathway can produce δ13C signatures that are distinct from the C3 pathway due to differences in isotopic discrimination during carbon fixation. Analyses were performed on Lepidodendropsis sp. and coeval presumed C3 plants (i.e. Genselia and Rhodeopteridium sp.) from the same fossil plant assemblage within the Price Formation of southwestern Virginia, U.S.A. The investigated plant fossils were limited to single assemblages from four localities within the Price Formation in an attempt to control differences in environmental conditions (differences in CO2, local climate, etc.) and diagenetic history that could affect the carbon isotope compositions of the fossil plants. The full dataset yielded a mean δ13C of −22.5 ± 0.7 ‰ for the CAM/CAM-like plants (n = 35) and a mean δ13C of −22.7 ± 0.7 ‰ for the suggested C3 plants (n = 36). The lack of isotopic difference between the coeval C3 plants and that of Lepidodendropsis does not preclude the possibility that these plants were using a CAM pathway and leaves open three possibilities for the photosynthetic pathway that Lepidodendropsis employed: 1) the C3 metabolism 2) aquatic CAM or 3) facultative CAM. More broadly, our study provides a more systematic framework for future studies to test for the presence of a CAM or CAM-like pathway in ancient plants.
{"title":"Testing for presence of alternative photosynthetic pathways in plants during the Mississippian","authors":"Tara A. Putri , Benjamin C. Gill , Stephen E. Scheckler , Rachel Reid","doi":"10.1016/j.palaeo.2025.112819","DOIUrl":"10.1016/j.palaeo.2025.112819","url":null,"abstract":"<div><div>The evolutionary emergence of the CAM (Crassulacean Acid Metabolism) photosynthetic pathway is unknown, but some studies have speculated it may have emerged during the Devonian-Carboniferous when vascular plants first proliferated in terrestrial environments. Specifically, some Carboniferous arborescent lycopsids (e.g., <em>Lepidodendropsis</em>) have morphological features similar to modern CAM plants. In this study, we systematically examine the carbon isotope compositions of an assemblage of Tournaisian (Mississippian) <em>Lepidodendropsis</em> for evidence of alternative photosynthetic pathways. Previous work suggests that the CAM pathway can produce δ<sup>13</sup>C signatures that are distinct from the C<sub>3</sub> pathway due to differences in isotopic discrimination during carbon fixation. Analyses were performed on <em>Lepidodendropsis</em> sp. and coeval presumed C<sub>3</sub> plants (i.e. <em>Genselia and Rhodeopteridium</em> sp.) from the same fossil plant assemblage within the Price Formation of southwestern Virginia, U.S.A<em>.</em> The investigated plant fossils were limited to single assemblages from four localities within the Price Formation in an attempt to control differences in environmental conditions (differences in CO<sub>2</sub>, local climate, etc.) and diagenetic history that could affect the carbon isotope compositions of the fossil plants. The full dataset yielded a mean δ<sup>13</sup>C of −22.5 ± 0.7 ‰ for the CAM/CAM-like plants (<em>n</em> = 35) and a mean δ<sup>13</sup>C of −22.7 ± 0.7 ‰ for the suggested C<sub>3</sub> plants (<em>n</em> = 36). The lack of isotopic difference between the coeval C<sub>3</sub> plants and that of <em>Lepidodendropsis</em> does not preclude the possibility that these plants were using a CAM pathway and leaves open three possibilities for the photosynthetic pathway that <em>Lepidodendropsis</em> employed: 1) the C<sub>3</sub> metabolism 2) aquatic CAM or 3) facultative CAM. More broadly, our study provides a more systematic framework for future studies to test for the presence of a CAM or CAM-like pathway in ancient plants.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"665 ","pages":"Article 112819"},"PeriodicalIF":2.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454200","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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