Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Ordovician integrative stratigraphy of the HK-1 Borehole in the South Yellow Sea and its geochronological and paleoclimatic implications","authors":"Changgui Xu ,&nbsp;Xin Wang ,&nbsp;Huaichun Wu ,&nbsp;Bo Yang ,&nbsp;Rucai Zhang ,&nbsp;Haifeng Yang ,&nbsp;Zhen Huang ,&nbsp;Zijun Han ,&nbsp;Qiang Fang","doi":"10.1016/j.palaeo.2025.113057","DOIUrl":"10.1016/j.palaeo.2025.113057","url":null,"abstract":"<div><div>The South Yellow Sea Basin, situated at the northeastern margin of the Lower Yangtze Craton, represents a significant prospective area for hydrocarbon exploration. However, insufficient drilling data has impeded the comprehensive study of Ordovician strata, which are crucial for evaluating the characteristics of the petroleum system. The HK-1 Borehole marks the first encounter with Ordovician strata in this region, offering essential stratigraphic records that enhance the understanding of early Paleozoic tectonic, climatic, and environmental evolutions. In this study, carbon isotope stratigraphy and cyclostratigraphy from Ordovician strata at the depths of 4083 m to 4492 m in the HK-1 were studied to establish relationships for stratigraphic correlation on a global scale. Two carbon isotopic shifts through middle Darriwilian to Katian have been recognized, including Middle Darriwilian Isotopic Carbon Excursion (MDICE) and Pagoda Isotopic Carbon Excursion (PICE). The identification and documentation of these anomalies further reinforce both regional and global correlations within the Ordovician succession on the Lower Yangtze Craton. Astronomical calibration of ∼11 m Th (Thorium) cycles to 405-kyr orbital eccentricity cycle period aligns other significant, shorter sedimentary cycles to periods recognizable as short orbital eccentricity (136 kyr and 100 kyr), obliquity (32.4 kyr), and precession (18.4 kyr). Astronomical calibration produces an ∼12-Myr floating time scale using twenty-nine 405-kyr eccentricity cycles, which indicates a presumed age of ∼462.6 Ma for the lowermost sediments of HK-1 Borehole. Our proxy-based study also shows that the PICE was linked to marine anoxia during a global sea-level rise. In contrast, the increased influx of lighter organic carbon during sea-level regression may have disturbed the MDICE.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113057"},"PeriodicalIF":2.6,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169044","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":"Paired stable carbon isotope in carbonate and Cladophora: A novel and quantitative proxy for palaeolake level variations on the northeastern Qinghai-Tibet Plateau","authors":"Yixuan Li ,&nbsp;Xiangzhong Li ,&nbsp;Shutao Huang ,&nbsp;Jie Lin","doi":"10.1016/j.palaeo.2025.113044","DOIUrl":"10.1016/j.palaeo.2025.113044","url":null,"abstract":"<div><div>Stable organic carbon isotopes (δ¹³C_org) in lacustrine sediments have been widely used for palaeoenvironmental reconstructions, with bulk δ¹³C_org values inherently integrating signals from diverse organic sources. <em>Cladophora</em>, a common alga genus in Qinghai-Tibet Plateau (QTP) lakes, potentially serves as a robust archive for source-specific δ¹³C_org. In this study, we reevaluated the potential factors influencing <em>Cladophora</em>-derived δ¹³C (δ¹³C_{<em>Clad</em>}) by analyzing samples collected from varying water depths in three northeastern QTP lakes (Qinghai Lake, Tuosu Lake, and Gahai Lake). Our results show that δ¹³C_{<em>Clad</em>} is not only strongly correlated with the photosynthetic activities modulated by water depth, but with the δ¹³C values of dissolved inorganic carbon (DIC) in different lakes. Therefore, to minimize interference from lake-level signals influenced by catchment-scale carbon cycle perturbations in δ¹³C_{<em>Clad</em>}-based reconstructions, we further established paired stable organic carbon isotopes (Δ¹³C_{<em>Clad</em>}), derived by subtracting carbonate carbon isotopes (δ¹³C_DIC) from δ¹³C_{<em>Clad</em>}, as a novel and quantitative proxy for palaeolake level variations on the northeastern QTP. Then, we reconstructed lake-level fluctuations using this equation in Lake Tuosu since 1600 CE (known as the Little Ice Age). The record reveals four distinct phases: (1) an initial post-1600 CE rise culminating in 1700 CE; (2) sustained high levels until 1885 CE; (3) a decline to minimal levels during 1885–1965 CE; and (4) a post-1965 CE recovery likely driven by anthropogenic and climatic drivers. These fluctuations exhibit coherence with tree-ring based precipitation reconstructions across the eastern QTP but display temporally asymmetric responses to solar irradiance—showing strong synchronization during the 1645–1715 CE Maunder Minimum yet decoupling thereafter. This “phase-mismatch” pattern underscores the transitional climate regime of the northeastern QTP, where interactions between westerly circulation and monsoon dynamics modulate hydrological responses to external forcing.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113044"},"PeriodicalIF":2.6,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147167","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":"Onset of large-scale terrestrial organic carbon burial driven by Early Devonian changes in vascular plants and environments","authors":"Lusheng Yin ,&nbsp;Minfang Yang ,&nbsp;Jing Lu ,&nbsp;Ziyu Ling ,&nbsp;Xiaoyu Hu ,&nbsp;Xiao Bian ,&nbsp;Kai Zhou ,&nbsp;Peixin Zhang ,&nbsp;Le Liu ,&nbsp;Longyi Shao ,&nbsp;Jason Hilton ,&nbsp;David P.G. Bond","doi":"10.1016/j.palaeo.2025.113039","DOIUrl":"10.1016/j.palaeo.2025.113039","url":null,"abstract":"<div><div>The Early Devonian witnessed a major phase in the terrestrialization of land by plants. Understanding the implications for organic matter formation and accumulation during this interval is key to understanding global carbon burial. Existing research on the Early Devonian primarily focuses on marine carbonate records that do not permit evaluation of the mechanisms of terrestrial organic carbon burial, particularly in the early stages of plant colonization. Here, we examine facies associations, environmental evolution, and organic carbon burial within the late Pragian aged Posongchong Formation at the Zhichang section in Wenshan, Yunnan Province, China, a formation previously noted for recording the early radiation of land plants in coastal settings. Sedimentological and geochemical data include: (1) Paleosalinity proxies (B* and B/Ga) and sedimentary structures that indicate fluviolacustrine Facies Association (FA A), tidal flat (FA B), and shallow marine (FA C) facies developed in the study area, with two pulses of deepening separated by shallowing; (2) Total Organic Carbon (TOC) and kerogen maceral analyses that reveal an increase in terrestrial organic carbon content derived from terrestrial higher plants and phytoplankton; and (3) Organic matter preserved in coaly and carbonaceous shales that is mainly derived from continental higher plants that grew in a restricted, stable freshwater-brackish lagoon and floodplain environment. The land plant radiation recorded by the Posongchong Formation occurred within a stable coastal plain that provided a suitable setting for the supply and preservation of organic carbon in this early terrestrial ecosystem, in turn influencing the development of global terrestrial carbon burial.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113039"},"PeriodicalIF":2.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144105304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-resolution magnetostratigraphy of the Lower Cretaceous Dabeigou Formation in the Luanping Basin, northern China","authors":"Zhongshan Shen ,&nbsp;Zhiqiang Yu ,&nbsp;Zuohuan Qin ,&nbsp;Dangpeng Xi ,&nbsp;Gang Li ,&nbsp;Huaiyu He ,&nbsp;Chenglong Deng ,&nbsp;Zhonghe Zhou","doi":"10.1016/j.palaeo.2025.113021","DOIUrl":"10.1016/j.palaeo.2025.113021","url":null,"abstract":"<div><div>The Lower Cretaceous Dabeigou Formation and its equivalent strata in northern Hebei Province, China, are of great interest because they contain early representatives of the Jehol Biota, and record significant evolutionary and geological events. Despite recent advances in paleontology, biostratigraphy, radiometric dating and cyclostratigraphy, there is no consensus about the exact age of the Dabeigou Formation. Here, we report new high-resolution magnetostratigraphy coupled with detailed rock magnetic results from the Zhangjiagou section in the Luanping Basin. Rock magnetic results indicate that both magnetite and greigite are the primary carriers of the characteristic remanent magnetizations. Correlation to the geomagnetic polarity timescale was achieved by integrating magnetostratigraphy and previously published SIMS U<img>Pb zircon ages for the same section. Magnetostratigraphic results show that the sedimentary succession spans from Subchron M10Nn.3n to Subchron M10Nn.1n, and the age of the section can be constrained to the early Hauterivian stage. Therefore, the basal age of this succession is no later than 132 Ma, providing new constraints on the formation age of the Luanping Basin and a minimum age estimate for the early representatives of the Jehol Biota. Our new magnetostratigraphic findings provide important evidence for integrating marine and terrestrial records and further lay a foundation for studying paleoenvironmental changes and their impact on the evolution of the Jehol Biota.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113021"},"PeriodicalIF":2.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212913","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":"Significant shifts of sedimentary environment and carbon burial during the middle Holocene on the Sunda Shelf","authors":"Kaikai Wu ,&nbsp;Shengfa Liu ,&nbsp;Liang Wang ,&nbsp;Che Abd. Rahim Mohamed ,&nbsp;Hui Zhang ,&nbsp;Chuanzhen Zhu ,&nbsp;Bingjie Sun ,&nbsp;Jian Chen ,&nbsp;Xuefa Shi","doi":"10.1016/j.palaeo.2025.113052","DOIUrl":"10.1016/j.palaeo.2025.113052","url":null,"abstract":"<div><div>Changes in sedimentary environments and carbon burial exert significant impacts on regional and global environmental and climatic systems. However, the long-term evolution of sedimentary environment and carbon burial on the Sunda Shelf remains poorly understood. In this study, we analyzed the elemental geochemistry and organic carbon composition of core CJB01–64 from the central Sunda Shelf to elucidate the evolutionary history of sedimentary environments and carbon burial since the last deglaciation, as well as to reveal their controlling mechanisms and climatic-environmental implications. Our results indicate a significant shift in sediment provenance in the central Sunda Shelf around 7.5 ka. Prior to this time, sediments were primarily derived from Thai rivers and the Mekong River, whereas after 7.5 ka, sediment contributions expanded to the Mekong River, Thai rivers, and Malay Peninsula rivers. The intensity of chemical weathering on the Sunda Shelf markedly weakened after 7.5 ka, with the East Asian Summer Monsoon serving as the primary controlling factor. The sedimentary environment transitioned from a nearshore terrestrial-dominated setting to a marine-dominated regime around 7.5 ka. Furthermore, the organic carbon burial flux decreased significantly after 7.5 ka, dropping by nearly sixfold. Since the last deglaciation, organic carbon burial on the low-latitude Sunda Shelf has been predominantly regulated by sea-level fluctuations and East Asian Summer Monsoon variability, whereas high-latitude shelves exhibited carbon burial principally governed by global climatically driven processes. Notably, during low sea-level periods of the last deglaciation, the Sunda Shelf exhibited a sedimentary carbon burial flux of 8.816 Tg/a, indicating that the Sunda Shelf was a critical carbon sink during this period. Our findings highlight the Sunda Shelf's sedimentary environmental dynamics and carbon burial evolution as potential responders to and influencers of regional and global environmental and climatic changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113052"},"PeriodicalIF":2.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-frequency glacial climate instability during the Early Pleistocene: Insights from IODP site U1387 (Gulf of Cadiz)","authors":"Samanta Trotta ,&nbsp;Monica Duque-Castaño ,&nbsp;Teresa Rodrigues ,&nbsp;Antje H.L. Voelker ,&nbsp;Patrizia Maiorano ,&nbsp;Barbara Balestra ,&nbsp;José-Abel Flores ,&nbsp;Agata Siniscalchi ,&nbsp;Marina Addante ,&nbsp;Maria Marino","doi":"10.1016/j.palaeo.2025.113041","DOIUrl":"10.1016/j.palaeo.2025.113041","url":null,"abstract":"<div><div>We provide new high-resolution data on alkenone-derived sea surface temperature (SST) and calcareous plankton key taxa in temporally well constrained, high resolution benthic and planktonic oxygen isotope records at Integrated Ocean Drilling Program site U1387 in the Gulf of Cadiz. The investigated time interval encompasses the Early Pleistocene marine isotope stages (MIS) 48 to MIS 43. The aim is to evidence millennial climate variability during glacial phases of the “41 kyr world” and understand the impact of North Atlantic climate dynamics on the southern Portuguese margin. <em>Neogloboquadrina pachyderma</em> and <em>Coccolithus pelagicus</em> ssp. <em>pelagicus</em> record prominent, short-term abundance peaks concurrent with short-term SST minima and heavier values of ™¹⁸O in late MIS 48 and in the middle of MIS 46 and MIS 44. Superimposed on the obliquity and precession forcing, the wavelet analysis carried out on selected proxies (planktonic ™¹⁸O, <em>N. pachyderma</em>, <em>C. pelagicus</em> ssp. <em>pelagicus</em>, alkenone derived sea surface temperature) highlighted the occurrence of a higher frequency climate variability (&lt;7 ky) mostly in glacial time windows and recalling the millennial-scale climate oscillations known from the Middle and Late Pleistocene. These brief colder episodes in the Gulf of Cadiz were contemporary to the weakening of the Atlantic Meridional Overturning Circulation, water column stratification, and Ice Rafted Detritus (IRD) events in the IRD belt as recorded in paleoenvironmental proxies from northern Atlantic reference sites, evidencing a southward shift of the subarctic front and European icesheet instability. At site U1387, they have been interpreted as terminal stadial (in late MIS 48) and stadial events (in MIS 46 and MIS 44) indicating that the millennial-scale variability during the early Pleistocene was strong enough to affect the mid-latitudes of the southern Portuguese margin.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113041"},"PeriodicalIF":2.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138449","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 model for estimating trophic position in mammalian carnivores based on bone collagen individual amino acids nitrogen stable isotopes","authors":"Maciej T. Krajcarz ,&nbsp;Magdalena Krajcarz ,&nbsp;Rafał Kowalczyk ,&nbsp;Peter Tung ,&nbsp;Hervé Bocherens","doi":"10.1016/j.palaeo.2025.113040","DOIUrl":"10.1016/j.palaeo.2025.113040","url":null,"abstract":"<div><div>Trophic position, or the level occupied by an organism in the food chain, is a key characteristic for understanding its role in the recent or past ecosystem. Nitrogen stable isotopes in selected amino acids of bone collagen, in particular in the glutamate and phenylalanine, allow for quantification of the trophic position in fossils and thus, for reconstruction of the ecological history of species and landscapes. Applying this method for carnivorous mammals was limited until now due to the lack of a key parameter, the trophic discrimination factor (TDF) for collagen, representing an isotopic shift in amino acids from prey bone collagen to carnivore bone collagen. In this study, we determined this parameter in two carnivorans: the modern wolf and the Pleistocene cave hyena. We measured the glutamate and phenylalanine δ¹⁵N values in bone collagen of these carnivores and their prey, applying five models to estimate the mean diet. We proposed a new model of calculating the TDF for collagen-based data, with herbivores regarded as a baseline level. We found collagen–to–collagen glutamate-phenylalanine TDF in both studied carnivorans and in all models of the mean diet similar to each other, +4.8 ‰ on average. This value is lower than that determined previously in invertebrate proteins or in plant–to–vertebrate tissue systems. Our results allow for more accurate reconstruction of trophic position in carnivores, including paleontological and archaeological materials where bone collagen is the only available tissue. We applied our new herbivore model and collagen-based TDF to re-asses the trophic structure of an exemplary Late Pleistocene assemblage, and found that the Upper Paleolithic humans at this site occupied a higher trophic position than previously determined.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113040"},"PeriodicalIF":2.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134461","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":"First report of the hurdiid radiodont Ursulinacaris from the Cambrian Kaili Biota, South China","authors":"Xiuchun Luo ,&nbsp;XingLian Yang ,&nbsp;Jorge Esteve ,&nbsp;Dezhi Wang","doi":"10.1016/j.palaeo.2025.113036","DOIUrl":"10.1016/j.palaeo.2025.113036","url":null,"abstract":"<div><div>Radiodonts are globally distributed from the Cambrian Series 2 to Miaolingian. However, their occurrences in South China during the Miaolingian Epoch remains limited, particularly for hurdiids, which are highly abundant in other palaeocontinents. Here, we present the first discovery of hurdiid frontal appendages from the Cambrian Kaili Biota (Miaolingian) in South China. These appendages display distinctive morphological features, including five paired spiniform endites in the intermediate region, which facilitate their assignment to <em>Ursulinacaris</em> cf. <em>U. grallae</em>. This finding expands the palaeogeographic distributions of <em>Ursulinacaris</em>, which was previously thought to be confined to Laurentia in Miaolingian, and reinforces the biogeographic connection between Laurentia and South China during this time interval. An analysis of radiodont biodiversity patterns in Laurentian and South China suggests a shift in their evolutionary radiation center from shallow-water environments during the Cambrian Epoch 2 to deeper-water habitats of the Miaolingian. Furthermore, the alteration of radiodont biodiversity from the Cambrian Series 2 to Miaolingian may correlate with the Redlichiid-Olenellid Extinction Carbon Isotope Excursion (ROECE).</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113036"},"PeriodicalIF":2.6,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138441","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":"Ten years of Tridacna sclerochemistry at up to daily resolution from a controlled aquarium environment – Records of habitat change, induced seasonality and growth variability","authors":"Max Fursman ,&nbsp;Viola Warter ,&nbsp;Max Janse ,&nbsp;Willem Renema ,&nbsp;Christoph Spötl ,&nbsp;Iris Arndt ,&nbsp;David Evans ,&nbsp;Wolfgang Müller","doi":"10.1016/j.palaeo.2025.113022","DOIUrl":"10.1016/j.palaeo.2025.113022","url":null,"abstract":"<div><div>Giant clams such as <em>Tridacna</em> sp., with their rapid shell accretion (mm-cm/year), decade-long lifespans and aragonitic shells, are invaluable (palaeo)environmental archives, potentially providing information at (sub-)seasonal timescales. Royal Burgers' Zoo aquarium in Arnhem, The Netherlands, opened a live coral reef eco-display in 2000 and introduced <em>T. squamosa</em> from Vietnam in 2001. One specimen (TS2) that died in 2011 facilitated a decade-long comparison of carefully monitored aquarium conditions with <em>Tridacna</em> sclerochemistry and growth, whose results we present herein. Spatially resolved El/Ca ratios by LA-ICPMS (at up to daily resolution) as well as micromilled δ¹³C and δ¹⁸O data were transferred onto a sclerochronological framework at a daily resolution, which enabled the detailed correlation of aquarium parameters with sclerochemistry. We show that environmental stresses such as transportation, introduction to a new aquarium environment, shifts in water change regimes and artificial seasonality from 2009 onwards have severe impacts on the organism's growth and sclerochemistry, and are particularly manifest in this sample in increased Mg/Ca and Sr/Ca ratios. Growth rates were reduced from <span><math><mo>∼</mo></math></span>20 to <span><math><mo>∼</mo></math></span>7 μm/day during transportation into the aquarium, and from <span><math><mo>∼</mo></math></span>10 to <span><math><mo>∼</mo></math></span>2 μm/day during shifts in water change regimes in the aquarium. A disruption of daily El/Ca cyclicity was marked during transportation-induced stress, but within three weeks of introduction the organism acclimatised to the aquarium and returned to natural growth rates and cyclicity. Three years of induced temperature seasonality (25.0–26.5 °C) most notably affected Na/Ca, while the resulting expected δ¹⁸O variability was not resolvable due to TS2's strongly decreased growth rate coupled with our large drill-step size for sampling. Despite a transient spike in aquarium [NO^-₃] from <span><math><mo>∼</mo></math></span>0.02 to 2.4 mg/L, caused by accidental over-fertilisation, no stress effect was apparent in the organism's sclerochemistry or growth rate. Changes in the water-exchange regime appear to have far more sclerochemical impact, as these are reflected in the overall δ¹⁸O, Ba/Ca and associated growth rates. The detailed decade-long <em>Tridacna</em> record shows that even systems with comparatively little environmental variability can produce large degrees of shell heterogeneity, and also highlights the importance of establishing a detailed (counted) chronology for sclerochemical interpretations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"675 ","pages":"Article 113022"},"PeriodicalIF":2.6,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263739","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":"Co-evolution of palaeolakes in the Hetao Basin and the Yellow River over the last 500 ka","authors":"Yuqi Zhao ,&nbsp;Niannian Fan ,&nbsp;Yu An ,&nbsp;Junsheng Nie ,&nbsp;Jordan T. Abell ,&nbsp;Zhangdong Jin ,&nbsp;Chengshan Wang ,&nbsp;Ruihua Nie ,&nbsp;Xingnian Liu","doi":"10.1016/j.palaeo.2025.113038","DOIUrl":"10.1016/j.palaeo.2025.113038","url":null,"abstract":"<div><div>The fluvial-lacustrine and aeolian deposits in the Hetao Basin provide a record of regional palaeo-environment changes that can be useful for constraining the evolution of the palaeo-Yellow River. Here, we provide a new chronology for middle Pleistocene through Holocene sedimentary sequences in the Hetao Basin. Combined with new micropaleontological results and previous geochemical and biological data, this framework reconstructs the hydro-geological evolution of the Hetao Basin over the last 500 ka. Based on the available field data and water balance modeling, we suggest that the palaeolakes in the Hetao Basin developed at least ∼450 ka ago, and subsequently expanded and contracted during interglacial and glacial intervals, respectively. The peak palaeolake area may have reached 34,000 km², covering most of the Hetao Basin, and would have been predominantly fed by the Yellow River. However, at ∼128 ka, the lake overflowed due to a significant wetter and warmer climate, and afterwards the Yellow River became reintegrated, flowing out of the Hetao Basin, likely along a near-modern pathway. During this process, the palaeolake area shrunk by about 85 % and only remained in the western part of the Hetao Basin. This smaller palaeolake was still fed by a branch of the Yellow River until about 5 ka. Our results better constrain the late Quaternary hydro-geological history of palaeolakes in the Hetao Basin on glacial-interglacial timescales. These findings are not only important for reconstructing the evolution of the palaeo-Yellow River, but also for understanding regional aeolian dynamics and hydraulic erosion processes in the Chinese Loess Plateau.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 113038"},"PeriodicalIF":2.6,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116956","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}