Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Quantitative fluvial geomorphological constraints on differential activity of boundary faults and phased uplift of the Bogda Mountains in the northern Tian Shan, NW China","authors":"Jiaoyan Yang ,&nbsp;Dongli Zhang ,&nbsp;Qi Su ,&nbsp;Haiyun Bi ,&nbsp;Yige Li ,&nbsp;Fuer Yang ,&nbsp;Wenjun Zheng","doi":"10.1016/j.palaeo.2026.113570","DOIUrl":"10.1016/j.palaeo.2026.113570","url":null,"abstract":"<div><div>The Bogda Mountains, located in the middle-eastern section of the northern Tian Shan, are the forefront of its growth and expansion toward the Junggar Basin. Since the late Cenozoic (∼30 Ma), intense activity along piedmont faults has driven the rapid uplift of the Bogda Mountains and shaped the fluvial landscape. In this study, we used the bedrock channel stream-power erosion model and topographic analysis tools to extract 61 watersheds within the Bogda Mountains. Geomorphological parameters including the hypsometric integral (HI) and normalized steepness index (<em>kₛₙ</em>) were also calculated. Results indicate that the landscape of the Bogda Mountains is primarily controlled by three active faults. The Fukang fault is currently the most active, whereas the North Bogda fault has gradually weakened. The South Bogda fault may have experienced a period of tectonic reactivation. The analysis of χ and Gilbert metrics suggest respectively different results of drainage divide migration, indicating a tectonically controlled pattern of non-uniform uplift in the Bogda Mountains and the differential activity of the boundary faults. The drainage divide currently maintains a state of dynamic equilibrium. In this study, knickpoint response times were calculated through reconstructing paleo-channel profiles, concluding that the Bogda Mountains have undergone two significant tectonic uplift events at approximately 25–20 Ma and 5 Ma.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113570"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080705","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":"Different responses of stalagmite oxygen and carbon isotopes reveal interhemispheric phasing of climate during the Marine Isotope Stage 4 to 3 transition","authors":"Gong-Zhe Chen ,&nbsp;Hao-Xiang Huang ,&nbsp;Shi-Tao Chen ,&nbsp;Shu Yang ,&nbsp;Zhen-Jun Wang ,&nbsp;Yong-Jin Wang ,&nbsp;Xian-Feng Wang","doi":"10.1016/j.palaeo.2026.113580","DOIUrl":"10.1016/j.palaeo.2026.113580","url":null,"abstract":"<div><div>Chronological uncertainties in paleoclimate records continue to obscure the interhemispheric phasing and driving mechanisms of Dansgaard–Oeschger (DO) events during the last glacial period. This study presents a high-precision ²³⁰Th-dated stalagmite record (YX53) from Yongxing Cave in central China, spanning 64.4–52.5 ka B.P. and covering DO events 18 to 14. The results show that variations in stalagmite <em>δ</em>¹⁸O, align closely in event structure with records of tropical precipitation, Intertropical Convergence Zone position, and Antarctic temperature, indicating a tropical–Southern Hemisphere climatic signal. In contrast, the <em>δ</em>¹³C record exhibits a pattern similar to Greenland temperature and dust variations, suggesting a primary response to North Atlantic climate variability. By analyzing the phase relationship between <em>δ</em>¹⁸O and <em>δ</em>¹³C within the same stalagmite, this study directly evaluates the relative timing of these climate signals under a unified chronology. We further improved the objectivity of the phase analysis by applying sub-decadal sampling, stricter statistical criteria, and intra-cave cross-validation. Results show that during the onset of DO events, changes in <em>δ</em>¹³C did not lag behind those in <em>δ</em>¹⁸O. This indicates that North Atlantic climate change was not delayed relative to tropical and Southern Hemisphere responses on decadal timescales, challenging the hypothesis of a Southern Hemisphere pacemaker for abrupt events during the Marine Isotope Stage 4 to 3 transition.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113580"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080709","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":"Sharp rise in cormorant (Phalacrocorax auritus) populations on Lake Ontario islands inferred from analyses of pond sediment cores","authors":"Daniel Dagodzo ,&nbsp;David C. Eickmeyer ,&nbsp;Linda E. Kimpe ,&nbsp;John P. Smol ,&nbsp;Jules M. Blais","doi":"10.1016/j.palaeo.2026.113603","DOIUrl":"10.1016/j.palaeo.2026.113603","url":null,"abstract":"<div><div>We measured biomarkers in pond sediment cores to infer population dynamics and track the ecological impacts of cormorants at East Brother Island (EBI), a cormorant-affected site, and Calf Island (CI), a reference site, in Lake Ontario over the past ∼170 years. Pronounced synchronous increases in cholesterol, cholestanol, cholestanone, coprostanol, epicoprostanol concentrations, expanded bird sterol index (EBSI), and δ¹⁵N values in the 1970s mark the establishment and rapid expansion of cormorant colonies at EBI. That time coincides with human-mediated environmental changes such as the regulation of organochlorine contaminants (e.g. DDT, PCBs), later introduction of invasive fish species, and reduced human disturbances. Declining C:N ratios and an initial increase in the plant stanol stigmastanol at EBI, following the initial colony establishment reflect short-term enhancement of terrestrial primary productivity driven by guano deposition. However, stigmastanol concentrations declined after ca. 1990, likely from vegetation degradation caused by the toxic effects of ammonia-rich guano and physical disturbances from bird nesting activities. We document the transformative impacts of cormorant populations on nutrient cycling, sediment processes, and vegetation dynamics at their nesting sites, providing a detailed record of how waterbird populations modify ecosystems over time, following their arrival. The findings highlight the value of integrating long-term ecological monitoring and adaptive management strategies to address the impacts of expanding waterbird populations, particularly in sensitive lacustrine environments.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113603"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081219","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":"Magmatic source effects on Zircon Eu anomalies: Refining the Late Cretaceous–Eocene uplift of the Gangdese Arc, Southern Tibet","authors":"Guang-Sheng Ren,&nbsp;Jin-Gen Dai,&nbsp;Xiang-Rui Liu,&nbsp;Xu Han,&nbsp;Bo-Rong Liu,&nbsp;Jia-Qi Sun","doi":"10.1016/j.palaeo.2026.113602","DOIUrl":"10.1016/j.palaeo.2026.113602","url":null,"abstract":"<div><div>The surface uplift history of the Gangdese Arc is critical for understanding tectonic and paleoenvironmental evolution of the southern Tibetan Plateau. While zircon Eu anomalies (Eu/Eu*) are widely used to infer crustal thickness and paleoelevation, their reliability is often compromised by heterogeneity in magma sources. Here we compile and analyze detrital and magmatic zircon Eu anomaly (Eu/Eu*) data from the Gangdese Arc. By applying rigorous screening to exclude S-type granitic zircons and analyzing distribution patterns, we identified pronounced bimodal Eu/Eu* values often mask critical geological signals: high values (∼0.51) at 100–80 Ma reflect the partial melting of eclogitized oceanic crust (source-controlled enrichment), while low values (∼0.22) at 65–40 Ma indicate crustal assimilation. By isolating these source-biased subpopulations, we reconstruct robust histories of crustal thickness and paleoelevation. Results indicate the Gangdese Arc underwent a major uplift phase during 80–70 Ma, reaching 3.0–4.0 km prior to the India–Asia collision, and maintained high elevations through 65–40 Ma. This revised uplift history is consistent with regional paleoclimate records and independent paleoaltimetric proxies. Our results highlight that magma source heterogeneity exerts an important control on zircon Eu/Eu* signatures. Accounting for such magmatic effects is essential for reliable crustal thickness reconstructions and for refining tectonic and paleoenvironmental interpretations of continental arcs worldwide.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113602"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171331","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":"Pass on the grass? The unexpected “last supper” of hypselodont Pachyrukhinae (Notoungulata, Mammalia) from the late Neogene of northwestern Argentina","authors":"Matías Alberto Armella ,&nbsp;Darin Andrew Croft","doi":"10.1016/j.palaeo.2026.113585","DOIUrl":"10.1016/j.palaeo.2026.113585","url":null,"abstract":"<div><div>Hypsodonty and later hypselodonty (open-rooted/ever-growing teeth) have traditionally been associated with grazing habits in notoungulates (a group of South American native ungulates) and many other mammalian herbivore lineages. Recent evidence has challenged this paradigm, casting doubt on a simple correlation between hypselodonty and diet in notoungulates. We tested this proposal in pachyrukhines –small, rodent-like notoungulates with sciuromorph cranial adaptations and hypselodont dentitions– using low-magnification dental microwear analysis to reconstruct their diets. We used a comprehensive reference collection of 140 extant mammals spanning six dietary categories to develop a robust statistical framework integrating exploratory analyses, multivariate statistics, and three machine learning algorithms: Linear Discriminant Analysis (LDA), Support Vector Machines (SVM), and Random Forest (RF). The LDA performed best, with 70% overall accuracy and substantial agreement (κ = 0.62). We applied this model to 38 fossil specimens of <em>Tremacyllus</em> and <em>Paedotherium</em> from the Late Miocene to Pliocene of northwest Argentina. Against traditional expectations, 77% of <em>Tremacyllus incipiens</em> specimens were classified as fruit-seed consumers, with prediction probabilities exceeding 95% in most cases; the remaining individuals were classified as browsers, grass-leaf consumers, or grazers (all with low prediction probabilities). <em>Paedotherium</em> specimens were classified as either fruit-seed consumers or grazers. Our results suggest that pachyrukhines were mainly fruit-seed consumers rather than grazers, challenging long-standing dietary interpretations. Dietary variability likely reflects spatial and temporal heterogeneity in Neogene landscapes and perhaps seasonal resource partitioning. Our findings highlight the importance of testing morphological inferences with direct dietary proxies and reveal unexpected convergent ecological specialization in these rodent-like notoungulates.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113585"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026205","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":"Weathering of the Gangdese Mountains and its impact on Paleogene seawater 87Sr/86Sr evolution","authors":"Xiaobai Ruan ,&nbsp;Albert Galy","doi":"10.1016/j.palaeo.2026.113581","DOIUrl":"10.1016/j.palaeo.2026.113581","url":null,"abstract":"<div><div>In this paper, the Sr geochemistry of rivers draining the eastern part of the Gangdese Mountains is used as an analogue to understand the contribution of this region to seawater ⁸⁷Sr/⁸⁶Sr ratios over the last 40 Ma. Dissolved Sr in the Chayu River Basin is radiogenic (⁸⁷Sr/⁸⁶Sr = 0.7313–0.7339) and more radiogenic compared to the adjacent Parlung Tsangpo Basin (0.7135–0.7174). In both basins, particulate detrital carbonates exhibit ⁸⁷Sr/⁸⁶Sr ratios consistent with the dissolved load. High dissolved K/Si ratios reflect the weathering of Rb-bearing minerals, yet their lack of covariation with ⁸⁷Sr/⁸⁶Sr ratios rules out silicate weathering as the driver of the radiogenic signal. Instead, this radiogenic Sr flux in the Chayu River Basin likely derives from the weathering of disseminated calcite. Disseminated calcite in granitoids of the eastern Gangdese Mountains, formed by melting during collision, records the mobilization of ⁸⁷Sr from less weatherable silicates into highly weatherable phases. Meanwhile, in the Parlung Tsangpo Basin, the less radiogenic signatures likely corresponds to the erosion and weathering of massive marine carbonate rocks that occur widely across that region. We infer that the Paleogene weathering of the radiogenic disseminated calcite within the eastern Gangdese and equivalent batholiths of the Lhasa, Tengchong and Sibumasu blocks likely triggered the rise in seawater ⁸⁷Sr/⁸⁶Sr at ∼40 Ma.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113581"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080704","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":"Rapid retreat of the East Asian summer monsoon at the end of the Holocene humid period accelerated the transition from broadleaf to pine forest landscapes in northern China","authors":"Linjing Liu ,&nbsp;Xin Mao ,&nbsp;Lei Song ,&nbsp;Xingqi Liu ,&nbsp;Dejun Wan ,&nbsp;Gaolei Jiang ,&nbsp;Jingsong Yang ,&nbsp;Hongmei Zhao ,&nbsp;Chengmin Wang ,&nbsp;Hua Zhao ,&nbsp;Rong Ma","doi":"10.1016/j.palaeo.2026.113609","DOIUrl":"10.1016/j.palaeo.2026.113609","url":null,"abstract":"<div><div>Understanding how vegetation responded to abrupt climate change in the past is critical for predicting its future dynamics under rapidly changing conditions. The climatic transition that ended the Holocene humid period provides an ideal case study for investigating the vegetation response to abrupt drying and prolonged drought stress. In this study, a high-resolution pollen analysis and the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model, which is based on relative pollen productivity, are used to quantitatively reconstruct the history of vegetation change from a lacustrine sediment sequence in the forest–steppe ecotone of northern China. Through a synthesis of regional pollen data, we reveal that the rapid southward retreat of the East Asian summer monsoon (EASM) between 6 and 5 ka BP did not cause a simple forest-to-steppe transition. Instead, it drove a shift from moisture-dependent broadleaf forests to drought-tolerant pine forests. We hypothesize that the region's complex topography buffered the environment against forest disappearance under unfavourable climatic conditions. However, the rapid transition from wet to dry climate exacerbated the drought stress on vegetation, driving forest type changes. These findings suggest that under future rapid climate change, vegetation responses may not follow simple advance or retreat patterns but could include the emergence of vegetation types distinct from those in modern forests.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113609"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080706","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":"Cave deposits U-Pb chronology: insights into the timing of Myotragus antiquus, cave evolution, and Pliocene sea level in Mallorca","authors":"Oana A. Dumitru ,&nbsp;Angel Ginés ,&nbsp;Victor J. Polyak ,&nbsp;Joaquín Ginés ,&nbsp;Pere Bover ,&nbsp;Joan J. Fornós ,&nbsp;Yemane Asmerom ,&nbsp;Bogdan P. Onac","doi":"10.1016/j.palaeo.2026.113604","DOIUrl":"10.1016/j.palaeo.2026.113604","url":null,"abstract":"<div><div>Cave deposits represent critical archives for reconstructing the timing of faunal evolution, speleogenesis, and sea-level change in coastal settings. Here, we present the first uranium‑lead (U-Pb) geochronological framework for the fossil-rich stratigraphy of Cova des Fum, Mallorca, offering new constraints on the age of the extinct goat <em>Myotragus antiquus</em>, the cave's speleogenetic history, and Pliocene sea-level history. Flowstone samples collected above and below a bone-bearing breccia yielded ages between 3.60 ± 0.77 Ma and 3.45 ± 0.68 Ma, placing the deposition of <em>M. antiquus</em> remains within the Late Pliocene. A basal flowstone age of 4.70 ± 0.55 Ma suggests that cave development began in the late Miocene, consistent with broader models of early speleogenesis in coastal eastern Mallorca. The stratigraphic succession, which includes interbedded aeolian calcarenites, suggests episodic sediment influx into a cave system already disconnected from active drainage. These flowstone ages, from an elevation of ∼82 m above present sea level, serve as terrestrial limiting points for sea-level reconstruction and align with other local estimates of Pliocene sea level derived from phreatic overgrowth on speleothems. By showing that <em>M. antiquus</em> is nearly one million years older than previously thought, this study provides the oldest well-resolved chronological constraints for the species, refines the timing of speleogenetic phases, and contributes new indirect evidence for Pliocene sea levels in the western Mediterranean.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113604"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080713","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 endothermy from tooth enamel(oid) oxygen isotopes in marine predators of the Late Cretaceous Western Interior Seaway, USA","authors":"Chelsea M. Comans ,&nbsp;Thomas S. Tobin ,&nbsp;Rebecca L. Totten","doi":"10.1016/j.palaeo.2026.113578","DOIUrl":"10.1016/j.palaeo.2026.113578","url":null,"abstract":"<div><div>We analyze stable oxygen isotopes (δ¹⁸O_p) of tooth enamel(oid) from fossil marine predators from the Smoky Hill Chalk Member of the Niobrara Formation (Kansas, USA) to investigate the thermoregulatory modes of shark, bony fish, and mosasaur taxa that lived in the Western Interior Seaway (WIS) of North America during the Late Cretaceous. Through comparing these taxa with the co-occurring ectothermic bony fish †<em>Enchodus</em>, which serves as a proxy for ambient conditions, we assess the relative δ¹⁸O_p values of 21 individual organisms across nine genera, using data measured from 47 fossil teeth. The mosasaur taxa (†<em>Platecarpus</em> and †<em>Tylosaurus</em>) exhibit significantly lower δ¹⁸O_p values than †<em>Enchodus</em> that are consistent in the direction and magnitude expected for endothermy in this group. Most shark taxa, by contrast, are likely ectothermic because their δ¹⁸O_p values overlap with those of †<em>Enchodus</em>. The durophagous shark †<em>Ptychodus</em> and large predatory bony fish †<em>Xiphactinus</em>, however, record significantly lower δ¹⁸O_p values than <em>Enchodus</em> and other sharks, which we interpret as indicative of elevated body temperatures consistent with endothermy and migration. Comparison with the Gulf Coastal Plain (GCP) of North America reveals that †<em>Ptychodus,</em> †<em>Cretoxyrhina,</em> †<em>Platecarpus,</em> and †<em>Tylosaurus</em> have similarly low δ¹⁸O_p values across both regions. The consistency of δ¹⁸O_p value offsets for †<em>Ptychodus</em> across species and regions suggests that endothermy was a trait inherent to this genus. Differences in δ¹⁸O_p value offsets (from local †<em>Enchodus</em> values) between WIS and GCP for †<em>Tylosaurus</em> and †<em>Cretoxyrhina</em> may reflect differences in respective study sample size, methodology, and ecological factors, namely migration, and regional ecological differences and ontogenetic habitat partitioning within †<em>Cretoxyrhina</em>. Further, these new data support previous findings that †<em>Cretalamna</em> was ectothermic and †<em>Cretoxyrhina</em> was endothermic. The prevalence of endothermy in Late Cretaceous sharks is likely higher than previously thought, challenging hypotheses of endothermy evolution in Late Cretaceous sharks.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113578"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026204","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 tuff constraints on episodic volcanism and consequent carbon sequestration during the Ediacaran-Cambrian transition in South China","authors":"Zhen Yang ,&nbsp;Yong Fu ,&nbsp;Zongxiang Zhang","doi":"10.1016/j.palaeo.2026.113605","DOIUrl":"10.1016/j.palaeo.2026.113605","url":null,"abstract":"<div><div>Tuffs (or K-bentonites) were widely developed in South China during the Ediacaran–Cambrian (<em>E</em>-C) transition. These volcaniclastic layers are typically intercalated within dolostones and phosphorites in Yunnan, whereas they occur primarily within cherts in Guizhou and Hunan. They are often overlain by black shale series, overall. An integrated geochemical and geochronological study has been conducted on tuff layers from two continuous deep-water sedimentary successions in South China, in order to examine the influence of volcanic activity on the paleoenvironment and its potential role as a carbon-sink trigger. Samples were collected from the middle Liuchapo Formation at the Bahuang section (Tongren) and from the topmost Liuchapo Formation at the Yacha section (Sansui). Analytical work included whole-rock major and trace elements, zircon U<img>Pb dating and trace elements, and Lu<img>Hf isotopic analysis. The study reveals that the zircon crystallization age of the Bahuang tuff is 549.9 ± 2.0 Ma (MSWD =0.28), and that of the Yacha tuff is 513.4 ± 2.1 Ma (MSWD =0.07). The zircon ε_Hf(t) values of the Bahuang tuff are predominantly negative, ranging from −5.17 to 2.77, while those of the Yacha tuff range from −0.71 to 4.67. Indicates that the magmatic sources for both the Bahuang and Yacha tuffs were derived from the mantle and juvenile lower crust, with the Bahuang tuff incorporating a greater proportion of ancient crustal material. The magmatic oxygen fugacity of both the Bahuang and Yacha tuffs was relatively lower, with Yacha tuff exhibiting slightly higher values than Bahuang tuff. The influence of oxygen fugacity on carbon sedimentation appears insignificant. Following the volcanic activity, these parameters K₂O, Al₂O₃, and ^TFe₂O₃ of black shale showed significant increases, with TOC exhibiting a clear positive correlation. This demonstrates that volcanic activity introduced nutrients such as Fe, K, Ca, and P, thereby enhancing paleo-productivity and facilitating the enrichment of organic carbon. This indicates that volcanic activity during the <em>E</em>-C transition acted as a trigger for enhanced carbon sinks.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113605"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171279","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}