Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Stepwise intensification of human activities over the past two millennia in Southwest China","authors":"Kai Cui ,&nbsp;Yongbo Wang ,&nbsp;Xingqi Liu ,&nbsp;Ji Shen ,&nbsp;Yong Wang","doi":"10.1016/j.palaeo.2025.113185","DOIUrl":"10.1016/j.palaeo.2025.113185","url":null,"abstract":"<div><div>As human activities accelerate landscape change, it is crucial to evaluate the potential impacts of natural climate fluctuations and anthropogenic disturbances. Accordingly, a continuous sediment record covering the past two millennia was collected from Beihai Wetland, Yunnan Province. The geochemical elemental compositions and organic material content were subsequently analyzed to evaluate the interactions between climate and human activities on the sedimentation process. The geochemical elements, such as K, Ti, Fe and Al, illustrate an overall increase in detrital inputs following catchment erosion. The total organic carbon content and C/N ratio suggest that organic matter deposition gradually decreased while terrestrial contribution increased. The geochemical indices mainly respond to regional moisture conditions before 1000 CE, and show a broadly consistent pattern with the intensity of Asian Summer Monsoon, suggesting that climate variation was a predominant factor in the catchment erosion and deposition process. Accordingly, the collapse of Nanzhao Kingdom in southwest China in 902 CE is supposed to be closely associated with an exceptionally weak monsoon phase between 900 and 1000 CE. During the Medieval Warm Period and the Little Ice Age, the terrestrial contributions (indicated by compositions of Ti, Fe, K, Al, and C/N ratio) increased significantly, which cannot be solely attributed to the gradual decline in monsoonal precipitation. The substantial population growth and implementation of production policies in southwest China provide a plausible explanation for such phenomenon. Since the Ming Dynasty, the impact of human activities on the landscape evolution and subsequent sedimentation process gradually increased and overcame the impact of natural climate fluctuations. In addition, various sediment records and historical documents have also supported the gradual intensification of human activity in southwest China over the past two millennia. The results revealed the interactive influence of climate change and human activities on the sedimentation process, providing a scientific basis for understanding the mechanisms of environmental changes during historical periods.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113185"},"PeriodicalIF":2.7,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810102","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":"Island-hopping across the Wallace Line: A new Pleistocene Stegodon fossil skull from Luzon (Philippines) reveals dispersal links to Wallacea","authors":"Meyrick U. Tablizo ,&nbsp;Gerrit D. van den Bergh ,&nbsp;Allan Gil S. Fernando","doi":"10.1016/j.palaeo.2025.113186","DOIUrl":"10.1016/j.palaeo.2025.113186","url":null,"abstract":"<div><div>Southeast Asia is renowned for its exceptional biodiversity and complex biogeography, shaped by major faunal boundaries such as the Wallace and Huxley Lines. Among the most iconic Pleistocene megafauna in the region is <em>Stegodon</em>, an extinct proboscidean relative of modern elephants, commonly represented in fossil assemblages across various Southeast Asian islands, including Luzon, Philippines. However, the evolutionary history and dispersal of the Luzon <em>Stegodon</em> remain poorly resolved due to the scarcity of diagnostic cranial material. Here, we present the first formal description of a <em>Stegodon</em> skull from the Philippines, recovered from Lannig, Solana, Cagayan (northeastern Luzon), along the northwestern flank of the Enrile Anticline, and likely originating from the lower Awidon Mesa Formation, estimated to be of late Early Pleistocene age. The specimen (CM-B-1-2021) is fragmentary and deformed, preserving a complete right upper cheek tooth, interpreted as the first molar (M¹), and the proximal sections of two small tusks. Morphological and morphometric comparisons indicate it belonged to a late juvenile (approaching subadult) intermediate-sized individual with affinities to the <em>S. trigonocephalus</em> group. Notably, the molar's narrow, nearly subhypsodont morphology closely resembles that of <em>S. f. florensis</em> from Flores, Indonesia (late Early to Middle Pleistocene), suggesting a possible north–south faunal connection between the Philippines and Wallacea, island-hopping across the Wallace Line. This study provides new insights into <em>Stegodon</em> dispersal dynamics across Southeast Asia and highlights the need for a comprehensive reexamination of other Luzon <em>Stegodon</em> specimens to refine their taxonomy and clarify broader evolutionary patterns in the region.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113186"},"PeriodicalIF":2.7,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827690","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":"Anthropogenic forcing has impacted precipitation variability in the North China Monsoon Marginal Region","authors":"Xiaoen Zhao ,&nbsp;Chenxi Xu ,&nbsp;Feng Chen ,&nbsp;Étienne Boucher ,&nbsp;Martín Hadad ,&nbsp;Fidel A. Roig ,&nbsp;Jiafeng Xu ,&nbsp;Mao Hu ,&nbsp;Shijie Wang ,&nbsp;Heli Zhang ,&nbsp;Youping Chen ,&nbsp;Weipeng Yue ,&nbsp;Honghua Cao","doi":"10.1016/j.palaeo.2025.113180","DOIUrl":"10.1016/j.palaeo.2025.113180","url":null,"abstract":"<div><div>The Asian Summer Monsoon (ASM) is a crucial driver of precipitation, sustaining ecological balance and socio-economic development in North China. However, the extent to which climate change has influenced this monsoonal system, leading to detectable and attributable modifications in precipitation regimes, remains unclear. Here, we present a robust annual precipitation reconstruction spanning 1770–2020, using δ¹⁸O from tree ring cellulose and a simple linear regression model in the North China Monsoon Marginal Region (NCMMR). Reconstructed precipitation and independent hydroclimatic records reveal a pronounced drying trend across the NCMMR since the 1950s. Multiple linear regression modelling, water vapor transport analyses using ensemble means from the Community Earth System Model-Last Millennium Ensemble, and correlation analysis indicate that precipitation variability in the NCMMR is modulated by the Indian Ocean Dipole, El Niño-Southern Oscillation, Atlantic Multidecadal Oscillation, and Interdecadal Pacific Oscillation. Nevertheless, fingerprint analysis suggests that the observed precipitation decline since the 1950s is strongly associated with greenhouse gas concentrations, albeit partially offset by the effects of anthropogenic aerosol emissions and internal variability. The impact of greenhouse gas forcing on precipitation variability is expected to intensify in the coming decades.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113180"},"PeriodicalIF":2.7,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826782","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":"Latest Tortonian to early Pliocene interdune lake systems, southern Libya: Implications for the hydrology of the central Sahara","authors":"Mark W. Hounslow ,&nbsp;Helena E. White ,&nbsp;Nick Drake ,&nbsp;Vassil Karloukovski ,&nbsp;Sue J. McLaren ,&nbsp;Mustafa J. Salem ,&nbsp;Ahmed S. El-Hawat ,&nbsp;Osama Hlal","doi":"10.1016/j.palaeo.2025.113187","DOIUrl":"10.1016/j.palaeo.2025.113187","url":null,"abstract":"<div><div>Developing environmental and chronological data for the Miocene and Pliocene successions of the central Sahara provide a basis for refining the pacing of green Sahara episodes to consolidate debate about early hominin dispersal from eastern Africa. Sedimentological, isotopic and geomagnetic polarity datasets are used to assess the environment and age of the Zarzur Formation in eastern Fezzan, Libya. A magnetostratigraphy based on four sections, combined with a statistical comparison to the geomagnetic polarity timescale, indicate that the formation was deposited from 7.8 Ma to 4.3 Ma. Lacustrine facies comprise laminated, peloidal mud-grade carbonates (with localised gypsum) formed in varying fresh to hypersaline inter-dune lakes. A second lacustrine facies comprises gastropod- and ostracod-bearing calcareous sandstones, formed in lakes developed on sandy substrates. These systems evolved from earlier fluvial and sandy-playa environments developed in the latest Tortonian. Based on δ¹³C and δ¹⁸O from carbonates formed in the lacustrine systems and calcrete-related cements, water sources for the lake deposits varied between low to high salinity and were largely from westerly moisture sources likely from extreme precipitation events. Groundwater was an important source for the inter-dune lakes because of irregularity in precipitation. The timing of lacustrine carbonate formation was in part paced to deep lakes that developed in the East African Rift in the early Pliocene, although sandy substrate lakes also formed during the Messinian. Greening of the Libyan Fezzan during deposition of the Zarzur Formation promoted potential habitat pathways for early hominid dispersal from the Megalake Chad Basin.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113187"},"PeriodicalIF":2.7,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828971","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":"Organic carbon burial in a middle Eocene East Asian paleolake: Response to global and regional climate changes","authors":"Qiqi Li ,&nbsp;Shang Xu ,&nbsp;Fang Hao","doi":"10.1016/j.palaeo.2025.113183","DOIUrl":"10.1016/j.palaeo.2025.113183","url":null,"abstract":"<div><div>Organic carbon burial in lakes represents an important natural mechanism for long-term organic carbon sequestration and a critical component of the global carbon cycle. However, the dynamics of lacustrine organic carbon burial are more complex than marine systems, and the mechanisms linking it to global and regional tectonic-climatic factors remain poorly understood. Here, we present an organic carbon burial record from the Dongying paleolake in the Bohai Bay Basin during the middle Eocene, integrated with high-resolution reconstructions of terrestrial paleoclimate and paleolake environments, to elucidate the controls on organic carbon burial in large lacustrine systems. Our findings indicate that middle Eocene terrestrial paleoclimate evolution in the Bohai Bay Basin was modulated by both global and regional forcing, resulting in two climate transitions at ∼43 Ma and ∼42 Ma. The first transition is attributed to the southward migration of subtropical high pressure caused by global cooling, while the second transition is associated with regional factors, including the Tibetan Plateau uplift and Paratethys Sea retreat. Terrestrial paleoclimate profoundly influenced the co-evolution of paleolake environments and organisms, causing significant differences in the source, accumulation, and preservation of organic matter during different phases, along with notable variations in organic carbon burial. We propose that organic carbon burial in the large paleolakes of the Bohai Bay Basin was a response to global and regional climate changes. These findings highlight the climatic sensitivity of lacustrine organic carbon burial, which may in turn play a key role in climate regulation. This study enhances our understanding of lacustrine carbon burial potential, patterns, and mechanisms, as well as the role of lakes in the global carbon cycle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113183"},"PeriodicalIF":2.7,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827691","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":"Carbon isotope chemostratigraphy and long-term sedimentary cyclicity of the mid-Cryogenian non-glacial interlude, Stuart Shelf, South Australia","authors":"Susanne Schmid ,&nbsp;Carmen B.E. Krapf ,&nbsp;Stefan Loehr ,&nbsp;Vincent Crombez ,&nbsp;Adrian J. Fabris ,&nbsp;Mitchell J. Bockmann ,&nbsp;Giovanni Spampinato","doi":"10.1016/j.palaeo.2025.113178","DOIUrl":"10.1016/j.palaeo.2025.113178","url":null,"abstract":"<div><div>The Cryogenian non-glacial interlude on the Stuart Shelf, South Australia comprises offshore to supratidal sedimentary successions deposited after the Sturtian glaciation at ∼660 Ma. This study's results present new data on fine-tuning carbon and oxygen isotope excursions in the Cryogenian, using material from five Stuart Shelf drillholes. The carbon isotope signature of the succession shows a broadly reproducible increase from −4.2 to +4 ‰ δ¹³C_carb from the base of the Tapley Hill Formation (including Sturtian cap carbonates) to the Brighton Limestone. This isotopic trend reflects changes in the marine dissolved inorganic carbon reservoir in the aftermath of the Sturtian glaciation, during an initial rapid transgression followed by an overall regressive phase. Most importantly, the observed isotopic trend is independent of the thickness of the different studied successions. Isotopic variations and sedimentary sequences are interpreted to be mainly controlled by change in the marine dissolved inorganic carbon reservoir and eustatic sea-level, both driven by global tectonic reconfigurations. Thickness variations relate to local or regional variations in subsidence rate and palaeo-topography. The secular trend within the non-glacial Cryogenian succession is interpreted to correlate with the Twitya carbon isotope excursion reported globally within a ∼10 Myr transgressive-regressive sedimentary cycle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"676 ","pages":"Article 113178"},"PeriodicalIF":2.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144779514","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":"Cenozoic climate cooling and tibetan plateau uplift jointly drive increased atmospheric dust deposition in Inland East Asia","authors":"Dongdong Wang,&nbsp;Ting Wang,&nbsp;Dawei Lv,&nbsp;Zhihui Zhang,&nbsp;Hongchang Hu,&nbsp;Aocong Zhang,&nbsp;Meng Zhang","doi":"10.1016/j.palaeo.2025.113177","DOIUrl":"10.1016/j.palaeo.2025.113177","url":null,"abstract":"<div><div>In the Earth system, atmospheric dust plays a crucial role in global climate evolution and biogeochemical cycles. Based on the hypothesis that the average content of inorganic components in coal throughout the regional geological history is mainly supplied by atmospheric dust, the coal ash yield, which serves as a proxy indicator for the inorganic components content in coal, was systematically collected, supplemented with measurements, and comprehensively analyzed for the sedimentary periods of the Eocene (50 Ma) and Miocene (10 Ma) epochs in East Asia. Accordingly, the relative concentration levels and deposition rates of atmospheric dust in East Asia during the Eocene and Miocene epochs were estimated, and their distribution characteristics and patterns were identified. The results indicate that under the driven by specific wind directions, atmospheric dust deposition rates in East Asia during the Eocene and Miocene epochs exhibited a significant negative correlation with distance from arid dust source areas; the concentration level and atmospheric dust deposition rates in East Asia during the Miocene epoch were significantly higher than those during the Eocene epoch, and the high value area is mainly located in the eastern part of the Tibetan Plateau. The analysis suggests that the global trend of cooling after the early to mid-Eocene epoch coincided with the rapid uplift of the Tibetan Plateau to approaching its present level during the Miocene epoch. The combined effects of these changes greatly enhanced the emission and transmission capacity of atmospheric dust, and altered its deposition pathways. This resulted in significant differences in the activity intensity and distribution of atmospheric dust in East Asia during the Eocene and Miocene epochs. The comprehensive analysis indicates that paleogeography and paleoclimate evolution were the primary factors controlling the intensity and distribution of atmospheric dust deposition in East Asia during these periods.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"676 ","pages":"Article 113177"},"PeriodicalIF":2.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144779515","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":"Oregon Oligo-Miocene herbivore community structure: Insights from morphology and stable isotope analysis","authors":"Dana M. Reuter ,&nbsp;Jensen M. Wainwright ,&nbsp;Jonathan M. Hoffman ,&nbsp;Mark T. Clementz ,&nbsp;Scott A. Blumenthal ,&nbsp;Samantha S.B. Hopkins","doi":"10.1016/j.palaeo.2025.113173","DOIUrl":"10.1016/j.palaeo.2025.113173","url":null,"abstract":"<div><div>Extant ungulates exhibit a wide range of niche-partitioning strategies to reduce competition. Niche partitioning is thought to facilitate species coexistence in highly diverse communities. However, how ungulates partitioned plant-food resources in the past and how those relationships changed over time in response to vegetation dynamics remains unclear. We present a synthesis of stable carbon and oxygen isotope compositions from newly analyzed (<em>n</em> = 134) and previously published (<em>n</em> = 77) fossil tooth enamel specimens from three Oregon Oligo-Miocene fossil assemblages (John Day, Mascall, and Rattlesnake Formations). We pair these data with body mass and tooth-crown height estimates to investigate ecological changes in Oregon's ungulate communities during the Oligo-Miocene (∼32–5 Ma), a time when grassland expansion coincided with significant changes in North American ungulate diversity. We find isotopic evidence that ungulates partitioned food resources in C₃-dominated ecosystems, particularly before and during the Mid-Miocene Climatic Optimum (MMCO). In contrast, the post-MMCO Rattlesnake Formation ungulates consumed isotopically similar C₃ plants. Morphological evidence supports these shifts, with a transition from low-crowned to mesodont and hypsodont teeth and a decline in small-bodied taxa. This work underscores the value of integrating isotopic and morphological data to better understand the ecological evolution of extinct communities.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113173"},"PeriodicalIF":2.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867435","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":"Modern silica sinter deposits from an island-arc setting and their potential for fossilizing plants","authors":"Aya Kubota ,&nbsp;Ryo Taniguchi ,&nbsp;Tomoyuki Ueda ,&nbsp;Yasuhiro Iba","doi":"10.1016/j.palaeo.2025.113176","DOIUrl":"10.1016/j.palaeo.2025.113176","url":null,"abstract":"<div><div>Silica sinters deposited by hot-spring activities form Lagerstätten with numerous three-dimensional, cell-preserved fossils. The formation processes and depositional facies of silica sinters have been documented in large-scale geothermal provinces, including mantle-plume hotspots and mid-ocean ridges. Silica sinters in these areas preserve plants and microbes which are adapted to survive under geothermal stress, and which live inside the hot-spring system. Most plants are, however, intolerant to this specific environment. They are growing outside the hot springs, their chance for being embedded and preserved in the silica sinters is thus limited. Paleodiversity estimates and paleoecological reconstructions of past silica sinter Lagerstätten are therefore considered to be ambiguous. Here, we present a new depositional facies model of silica sinter from a forested island-arc setting, and discuss the taphonomy of richly preserved plants from these settings. At Nakabusa Hot Springs in central Japan, numerous small seep points emerge on densely forested slopes, where they form silica sinters. These sinters are characterized by the incorporation of abundant modern plants and insects from the adjoining forests, in addition to temperature-specific microbes. Because narrow channels flow down steep slopes with little disturbance of the forests, a distinctive bio- and lithofacies has developed that richly preserves the present-day native vegetation. The facies model presented here can serve as a valuable modern analog for better understanding the depositional processes of plant-rich fossil silica sinters. It may further help to understand the factors controlling the fossilization of land-based vegetation, thereby improving its relevance for interpretations throughout the geologic record.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"679 ","pages":"Article 113176"},"PeriodicalIF":2.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020689","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":"Decadal-scale shifts in diatom assemblages since ∼1760 CE and their implications for biogenic silica recycling in the northern Yellow Sea","authors":"Yunying Duan ,&nbsp;Chongran Zhou ,&nbsp;Yujue Wang ,&nbsp;Ning Zhao ,&nbsp;Dongyan Liu","doi":"10.1016/j.palaeo.2025.113175","DOIUrl":"10.1016/j.palaeo.2025.113175","url":null,"abstract":"<div><div>Marine diatoms on continental shelves have faced significant challenges from climate change and human activities over the last century. Changes in diatom species composition and abundance can greatly affect the cycling of biogenic silica (BSi) and organic carbon (OC) in the ocean. Here, we reconstruct decadal-scale patterns in diatom fossil assemblages and geochemical parameters in the northern Yellow Sea, and analyze the associated environmental triggers and their potential influences on BSi/OC ratios. Sequential <em>t</em>-test and CONISS analysis identify two significant shifts. One shift occurred in the 1850s, marked by the proliferation of species preferring low salinity (<em>Actinocyclus ehrenbergii</em>, <em>Cyclotella stylorum</em>), coinciding with the diversion of the Yellow River from the southern Yellow Sea to the Bohai Sea. The second shift occurred in the 1970s, marked by increases of small and heavily silicified species (<em>Paralia sulcata</em>, <em>Thalassiosira eccentrica</em>), consistent with eutrophication in the northern Yellow Sea. After this second shift, BSi/OC ratios initially decreased, which might have been driven by increased terrestrial OC inputs. However, a subsequent increase in the BSi/OC ratio within this phase is attributed to enhanced diatom silicification. These findings suggest that shifts towards heavily silicified diatoms might substantially alter the marine silica cycle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"676 ","pages":"Article 113175"},"PeriodicalIF":2.7,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756881","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}