Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Dust supply to the West Philippine Sea since the Middle Pleistocene and distinct influences of the Westerlies after the Mid-Brunhes Event","authors":"Yun Cai ,&nbsp;Dong Xu ,&nbsp;Haifeng Wang ,&nbsp;Yanping Chen ,&nbsp;Haiyan Jin ,&nbsp;Yibing Li ,&nbsp;Weiwei Chen ,&nbsp;Liang Yi","doi":"10.1016/j.palaeo.2025.112961","DOIUrl":"10.1016/j.palaeo.2025.112961","url":null,"abstract":"<div><div>One of the long-standing debates focuses on whether iron (Fe) fertilization enhanced ocean productivity and fueled the biological carbon pump, contributing to glacial CO₂ drawdown. To date, dust flux has been a primary focus, while two other factors, namely dust source and transportation, are generally ignored. In this study, we report high-resolution dust records retrieved from rare earth element variabilities of a sediment core in the West Philippine Sea and discuss the potential linkage between our dust records and driving forces over the last 900 ka. We find an anti-phase relationship between the Ce-based dust record and the Ba-based productivity, both of which are characterized by three astronomical rhythms. By comparing our dust records with various wind proxies, we find that dust input in the study area is closely related to changes in the Westerlies and the East Asian Winter Monsoon, and the Westerlies became the dominant factor after the Mid-Brunhes Event (MBE). Along with the local minimum of obliquity, changes in dust input and ocean productivity are synchronously intensified during the post-MEB glacial periods. Together with comparisons to dust source changes in the inner Asia, we speculate that the strengthening and southward migration of the Westerlies may strengthen the influence of dust sources on marine productivity.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112961"},"PeriodicalIF":2.6,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoenvironmental evolution during the early Eocene climate optimum in a mid–high-latitude lake–marsh system, NE Asia","authors":"Penglin Zhang ,&nbsp;Qingtao Meng ,&nbsp;Fei Hu ,&nbsp;Lin Ma ,&nbsp;Jinguo Li","doi":"10.1016/j.palaeo.2025.112960","DOIUrl":"10.1016/j.palaeo.2025.112960","url":null,"abstract":"<div><div>The Early Eocene Climatic Optimum (EECO) represents a pinnacle of long-term global warming and is considered an analog for potential ecological impacts in a future high-CO₂ world (atmospheric <em>p</em>CO₂ &gt; 500 ppmv). Recent work from mid- to high-latitude lake–marsh systems in the Northern Hemisphere suggests that the EECO was characterized by a decoupled response in terrestrial and marine deposition, indicating that previous ecological models obtained from Ocean Drilling Program sites may not adequately explain the dynamics of the land–ocean ecological balance during the EECO. Here, new insights involving magnetic mineralogy, high-resolution dynamic sedimentary noise analysis, stable isotope examination, X-ray diffraction, and elemental investigations from the Dalianhe section in NE Asia, which record minimal organic δ¹³C values, sulfate reduction index values, limited C/N ratios, and relatively high dynamic noise orbital tuning lake levels of the EECO in lake–marsh systems at 53.1 ± 9.0°N. Moreover, lake–marsh systems at mid-high latitudes exhibit significantly greater temperature and precipitation shifts than do midlatitude marine systems, with the onset of a warming event (∼52.2 Ma) occurring after marine deposition. These analyses revealed that oceanic ventilation/mixing and East Asian monsoon responses were key drivers of the land–ocean ecological balance during the EECO. These global ecological dynamics demonstrate the sensitivity of terrestrial ecosystems and the lag of warming in response to extreme thermal events, which further constrains potential causal mechanisms for the EECO to multiple systems and highlights the importance of biogeochemical models for understanding global warming.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112960"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Miaolingian tubicolous fossils from North China and the persistence of the Ediacaran “worm-world”","authors":"Yuze Wang ,&nbsp;Michael Steiner ,&nbsp;Pingli Wang ,&nbsp;Xiaoyu Yang ,&nbsp;Renchao Yang","doi":"10.1016/j.palaeo.2025.112959","DOIUrl":"10.1016/j.palaeo.2025.112959","url":null,"abstract":"<div><div>The oldest undisputed metazoan body fossils are often represented by tubular remains, which led to the characterization of early ecosystems as the Ediacaran ‘worm-world’ fauna. Tubular body fossils continued to dominate during the Cambrian Bioradiation Event, primarily as three-dimensionally preserved small skeletal fossils, although their preservation varied widely. Most tubular fossils, however, lack soft tissue preservation, making it challenging to determine their biological affinities based solely on tube morphology. Here we describe well-preserved tubular fossils, <em>Longgangia bilamellata</em> gen. et sp. nov. and <em>Selkirkia</em> cf. <em>columbia</em>, from the Cambrian Mantou Formation (Miaolingian Series, Wuliuan Stage) in Burgess Shale-type preservation. <em>Longgangia bilamellata</em> gen. et sp. nov. features a double-layered tube wall, transversal annulations, and Y-shaped branching of half-ring annulations. The new species shows importance because of its resemblance in construction and preservation with Ediacaran tubular fossils, such as <em>Sinospongia</em>, <em>Sinotubulites</em>, and <em>Sabellidites</em>, therefore providing evidence for the persistence of the tube-dwelling lifestyle from the Ediacaran to the Cambrian (Miaolingian). This also highlights the evolutionary and ecological significance of tube-forming organisms during the Cambrian Bioradiation Event, an interval characterized by explosive metazoan diversification, biomineralization, genetic innovation, and niche specialization. The potential affinity with cnidarians, annelids, and hemichordates is discussed and an assignment of <em>Longgangia</em> gen. nov. to Annelida is considered most plausible. The new material also reveals that annelids are capable to create tubes by half-ring construction with Y-branchings of growth lines, thus emphasizing this tube construction is not exclusive to hemichordate pterobranchs.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112959"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for elevated wildfire activity during Cretaceous OAE 2 from eastern Tethys","authors":"Shuai Shi ,&nbsp;Xi Chen ,&nbsp;Huifang Guo ,&nbsp;Hanwei Yao ,&nbsp;Kaibo Han ,&nbsp;David B. Kemp ,&nbsp;Shengbao Shi ,&nbsp;Zhong Han ,&nbsp;Chengshan Wang","doi":"10.1016/j.palaeo.2025.112936","DOIUrl":"10.1016/j.palaeo.2025.112936","url":null,"abstract":"<div><div>Intensified frequency and scale of wildfires due to global warming has been increasingly recorded in recent years. Studies of wildfire activity during deep time greenhouse climate states are crucial for evaluating their likely impacts on the global environment and ecosystems in the future. Oceanic anoxic event 2 (OAE 2, ∼94 Ma), which was characterized by extremely high global temperature and a reduced equator-pole temperature gradient, could provide insights into our understanding of present-day global change processes. Here we provide data on polycyclic aromatic hydrocarbon (PAH) abundance from the Qiangdong section in the Tethyan Himalaya of southern Tibet to investigate wildfire behavior and its impact on the environment during OAE 2. Our results indicate a significant increase in the frequency of wildfires during the early part of OAE 2, followed by a rapid weakening. The change of PAH composition through OAE 2 in Qiangdong shares a similar trend to that previously found in the Western Interior Seaway (North America), indicating potentially globally elevated wildfire frequency during the early part of OAE 2. We also document a rapid increase in chemical index of alteration values in Qiangdong. These data, coupled with other proxies for weathering intensity through OAE 2, suggest that increased weathering during OAE 2 can be attributed at least in part to the effects of vegetation loss caused by wildfire. As such, we suggest that frequent wildfires during OAE 2 promoted the flux of nutrients to the oceans, thereby stimulating productivity that, in turn, increased the area of oceanic anoxia and organic carbon burial.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112936"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jurassic Trench basin of the Bangong-Nujiang Ocean in the Central Tibet: Record of clastic material mixing from Lhasa and Qiangtang terranes","authors":"Wen Lai ,&nbsp;Tao Deng ,&nbsp;Shifan Qiu","doi":"10.1016/j.palaeo.2025.112958","DOIUrl":"10.1016/j.palaeo.2025.112958","url":null,"abstract":"<div><div>The early growth, subduction, and demise history of the oceans in the Tibetan Plateau remains a subject of significant controversy, particularly the evolution history of the Bangong-Nujiang Meso-Tethyan Ocean. Sedimentary records serve as faithful carriers of orogenic belt evolution. Here, we present a newly-discovered Jurassic deep-marine gravity-fan succession that is over 250 m thick. We employ multi-proxy, single-grain provenance analysis and forward modeling of sediment mixture on this sequence to reconstruct the Mesozoic Meso-Tethyan Ocean tectonic evolution in the Lunpola region. We find the detritus was deposited in a trench and was sourced from the accretionary wedge, island arc, and continent block. Through quantitative mixed modeling calculations of detrital zircon U-Pb ages, we found that the two detrital zircon samples from the Jienu Group obtained in this study indicated a source contribution of 73–79 % from the Qiangtang terrane, 10–17 % from the Lhasa terrane, and 10–11 % from the Tethyan Himalayan tectonic belt. This result directly proves that the Bangong-Nujiang Ocean was the ancient ocean between the Lhasa terrane and the Qiangtang terrane, rather than between the Himalayan terrane and the Qiangtang terrane during Jurassic.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112958"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change and social turmoil in the late Qing Dynasty revealed by tree rings","authors":"Jinkuan Li ,&nbsp;Jiaxin Li ,&nbsp;Yameng Liu ,&nbsp;Keyu Zhang ,&nbsp;Xiaoxu Wei ,&nbsp;Mengyu Wang ,&nbsp;Jianfeng Peng","doi":"10.1016/j.palaeo.2025.112955","DOIUrl":"10.1016/j.palaeo.2025.112955","url":null,"abstract":"<div><div>The Qing Dynasty marked the final epoch of China's imperial era, has not only profound historical significance but also serves as a crucial lens for examining the impacts of climate change on dynastic transitions. This study utilizes the tree-ring width chronology of <em>Pinus bungeana</em> Zucc from the Shennong Mountain (SNM) in Henan Province to reconstruct the Standardized Precipitation Evapotranspiration Index (SPEI) for Central China spanning 1674–2018 CE (345 years), enabling a systematic investigation of climate change's role in the Qing Dynasty's decline. Results demonstrate a strong spatial correlation between the reconstructed SPEI and the White Lotus Uprising (WLU; 1796–1804 CE) epicenters, with precise alignment with regional drought patterns. Further analysis identified four significant cycles in the wet and dry fluctuations of Central China, with periods of 2-8a, 37-38a, 71-74a, and 159-173a. The reconstructed SPEI shows a significant positive correlation with sea surface temperatures (SST) in the North Pacific, highlighting the strong link between hydroclimatic changes in Central China and SST variability. Of particular interest is the severe drought that occurred between 1780 and 1820 CE, which coincided with the timing of the WLU and marked the decline of the Qing Dynasty. This drought is primarily attributed to changes in SST and the position of the North Pacific Subtropical High, underscoring the substantial impact of this climatic feature on regional moisture. Our reconstruction offers a novel perspective for assessing the impact of climate change on historical socio-economic conditions, and enhances our understanding of the interplay between climate change and the rise and fall of Chinese dynasties.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112955"},"PeriodicalIF":2.6,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Cambrian ROECE and DICE carbon isotope excursions in western Gondwana (Montagne Noire, southern France): Implications for regional and global correlations of the Miaolingian Series","authors":"Valentin Jamart ,&nbsp;Damien Pas ,&nbsp;Thierry Adatte ,&nbsp;Jorge E. Spangenberg ,&nbsp;Lukáš Laibl ,&nbsp;Allison C. Daley","doi":"10.1016/j.palaeo.2025.112951","DOIUrl":"10.1016/j.palaeo.2025.112951","url":null,"abstract":"<div><div>The Stage 4 – lower Guzhangian interval, which includes the Drumian and Wuliuan stages is critical for understanding biogeochemical and evolutionary events of the Cambrian. It coincides with the first widespread extinction event of the Phanerozoic associated with the negative Redlichiid – Olenellid Extinction Carbon Isotope Excursion (ROECE). It marks a shift from a lower Cambrian endemic-dominated fauna to a Paleozoic-type cosmopolitan-dominated fauna, and finally, the interval includes the negative Drumian Carbon Isotope Excursion (DICE). The precise identification of the ROECE to DICE interval beyond the tropical belts has been hindered by global regression events and the limited number of geochemical studies. However, rifting in the Mediterranean subprovince of western Gondwana during this transition provides a key sedimentary record of this interval in the southern hemisphere. The Ferrals-les-Montagnes section (Montagne Noire, southern France) offers crucial stratigraphic data for defining ROECE and DICE in western Gondwana. Although significant advances have been made in biostratigraphy, the geochemical characterization of ROECE – DICE carbon isotope excursions remain insufficiently explored, posing challenges for the precise delineation of the Series 2 – Miaolingian and Wuliuan – Drumian boundaries in Montagne Noire, where diagenetic alteration has further compromised fossil preservation. This study presents new paleontological (trilobites, echinoderms), carbon stable isotope (δ¹³C_carb, δ¹³C_org), and total organic carbon (TOC) datasets from the lower to middle Cambrian Ferrals-les-Montagnes succession. These data provide the first reliable ROECE and DICE records in western Gondwana, refining the Series 2 – Miaolingian and Wuliuan – Drumian boundaries in the region, and allow refining regional and global correlations of the Miaolingian Series.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112951"},"PeriodicalIF":2.6,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intensified East Asian summer monsoon facilitated the formation of the world's largest Late Miocene Hipparion fossil assemblage","authors":"Xiaojuan Li ,&nbsp;Wei Li ,&nbsp;Rui Zhang ,&nbsp;Xiaohao Wei ,&nbsp;Zhenwei Feng ,&nbsp;Chao Wang ,&nbsp;Zhihao Ma","doi":"10.1016/j.palaeo.2025.112956","DOIUrl":"10.1016/j.palaeo.2025.112956","url":null,"abstract":"<div><div>The Linxia Basin, located in the northeastern of the Tibetan Plateau, spans the Late Eocene to the Quaternary and provides an important window into the evolutionary history of the East Asian Monsoon and Eurasian vertebrate faunas. The sedimentary facies and stratigraphic framework of the Linxia Basin is best known in the northern part of the basin, however, in the basin's southern part, where rich fossils are preserved, the geological context is under-researched. Furthermore, the Late Miocene Yangjiashan fauna, which contains the world's most extensive <em>Hipparion</em> fossil assemblage, mostly occurs in the southern part of the Linxia Basin. This unique palaeontological assemblage raises intriguing questions regarding the exceptional preservation conditions and ecological factors that facilitated such an extraordinary accumulation of <em>Hipparion</em> fauna remains in a specific depositional environment. As an indicative fossil assemblage, the Yangjiashan fauna reflects the environmental characteristics of an open and dry-hot savanna ecosystem, providing an important historical framework for investigating the origin and evolution of the modern African savanna fauna. We applied a cyclostratigraphic approach to derive orbital ages for the Milankovitch cycles in the Qianshanliang section from the southern part of the basin, which preserves abundant fossils of Yangjiashan fauna. We analyzed the evolution of the East Asian Summer monsoon (EASM) by comparing climate indicators from the Bohai Bay, South China Sea, Linxia Basin, and Tianshui Basin.Additionally, we investigated the sedimentary characteristics of the classical sections containing abundant Yangjiashan fauna fossils in the Linxia Basin. We report an astronomically tuned age for the Qianshanliang section as 7.68–6.15 Ma, with the age range for the fossil bed precisely constrained to be 7.49–7.45 Ma. We also propose that the East Asian Summer Monsoon (EASM) experienced significant intensification around 7.7–7.2 Ma and 6.6–6.2 Ma. Combined with other magnetostratigraphic results from the Linxia Basin, these two periods of intensification of the EASM can be well-matched with the occurrence of the fossil layer of the Yangjiashan fauna and are frequently accompanied by coarse sedimentation. Based on these findings, we suggest that enhancements of the EASM in the Late Miocene played a crucial role in facilitating the formation of the Yangjiashan fauna fossils.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112956"},"PeriodicalIF":2.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Timing and structure of the short-lived Dansgaard-Oeschger 6 event in the Asian monsoon system","authors":"Qiyue Li ,&nbsp;Jingjing Lu ,&nbsp;Chenyang Zhang ,&nbsp;Guhan Liu ,&nbsp;Bin Zhao ,&nbsp;Jiaqi Cong ,&nbsp;Yue Yang ,&nbsp;Kan Zhao ,&nbsp;Jinguo Dong ,&nbsp;Hai Cheng ,&nbsp;Yujie Han ,&nbsp;Yijia Liang","doi":"10.1016/j.palaeo.2025.112953","DOIUrl":"10.1016/j.palaeo.2025.112953","url":null,"abstract":"<div><div>The structural features of the Asian monsoon in response to the Dansgaard-Oeschger (DO) event during the last glacial period are important for understanding and investigating the characteristics and dynamical mechanisms of the monsoon climate evolution. Here, based on seven ²³⁰Th dating results and 144 sets of oxygen and carbon isotope (δ¹⁸O and δ¹³C) data from a stalagmite (No. SM5) in Shima Cave, Hunan Province, we reconstruct climatic and environmental evolutions in the East Asian monsoon region, with an average resolution of ∼12 years over the period from 34.1 to 32.6 ka BP. SM5 δ¹⁸O record captures the rapid onset of the DO6 event at ∼33.8 ± 0.1 ka BP, with a negative isotopic bias of ∼1.8 ‰ over several decades, indicative of a fast recovery of the East Asian summer monsoon corresponding to Greenland warming. Considering the published stalagmite records with independent ²³⁰Th dating from the East Asian and the South American monsoon regions, we suggest that the DO6 should have started at ∼33.8 ± 0.1 ka BP and ended at ∼33.4 ± 0.1 ka BP, with a duration of ∼0.4 ± 0.1 ka BP. This further supports the accuracy of GICC05 chronology for Greenland ice cores surrounding this time interval. Besides, a “double peak” structure of DO6 Interstadial is observed in high-resolution mid- to low-latitude geological records and the CH₄ record but is missing in Greenland temperature record. These lines of evidence show that while the Asian monsoon was able to respond rapidly to northern high-latitude climates, it also featured centennial-scale oscillations possibly unique to the mid- to low-latitude regions.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112953"},"PeriodicalIF":2.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Oligocene paleosols in the Haltang Basin of northeastern Tibetan Plateau and their implications for the early extent of the Asian monsoon","authors":"Zhaobin Zhang ,&nbsp;Shuang Dai ,&nbsp;Xinnan Fang ,&nbsp;Xiaojun Ma ,&nbsp;Yufan Zhang ,&nbsp;Zhongzhao Ding ,&nbsp;Lingfeng Qin ,&nbsp;Chunyan Li ,&nbsp;Meng Zhou ,&nbsp;Tianqi Ji ,&nbsp;Jie Yang","doi":"10.1016/j.palaeo.2025.112952","DOIUrl":"10.1016/j.palaeo.2025.112952","url":null,"abstract":"<div><div>The Asian monsoon is thought to have established its present-day pattern and extent by ∼26 Ma. In this paper, we report a succession of Late Oligocene (∼23.94 Ma) luvic calcisols in the Haltang Basin, northeastern Tibetan Plateau, which allow us to evaluate the early history of the monsoon. The paleosols contain calcareous nodules and iron‑manganese cutans, and magnetic mineral content fluctuates in different horizons. These features indicate that paleosols formed in a humid climate, characterized by seasonal precipitation and eluviation. Analysis of the goethite/hematite ratio, burial depth and thickness of the Bk horizons, yield a paleoprecipitation estimate of 398–748 mm with a seasonal fluctuation of 88 mm. The mean annual temperature is estimated as ∼12 °C based on carbonate clumped isotope data from a carbonate nodule. This probably indicates a relatively lower elevation at that time. These palaeotemperature estimates, in combination with paleosol data and other proxies in the northeastern Tibetan Plateau, indicate that the Asian monsoon had onset in the Haltang Basin at ∼23.94 Ma. This suggests that the Asian monsoon was more widespread during the late Oligocene than it is today.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112952"},"PeriodicalIF":2.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845238","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}