Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"New aspects of the asymmetry of the Great American Biotic Interchange based on an analysis of the spatial and temporal structure of immigrant taxa at local scale","authors":"Luan Moldan Motta,&nbsp;Tiago Bosisio Quental","doi":"10.1016/j.palaeo.2025.112905","DOIUrl":"10.1016/j.palaeo.2025.112905","url":null,"abstract":"<div><div>The Great American Biotic Interchange (GABI) happened after the connection between North and South America was established, forming the Isthmus of Panama. The GABI comprised a well documented pattern characterised by an asymmetrical movement of mammalian migrants, with a higher proportion of North American taxa being found in South America than vice versa. Using mammal fossil occurrences from The Paleobiology Database (PBDB) and Generalized Linear Mixed Models, we tested if the proportion of immigrants in local assemblages presents a spatial structure with respect to the distance from the point of entrance to the new continent. We focused on two Pleistocene intervals, to evaluate if such spatial structures varied with time. We show that during early stages of the Pleistocene there was a strong negative relationship between the proportion of immigrants and distance to the point of continental connection in both North and South Americas. During the later stages of the Pleistocene a strong negative relationship was still recovered in North America; however in South America this relationship is weak, characterizing a new type of asymmetry between the continents. We conducted sensitivity analyses related to fossil dating uncertainty, the spatial definition of local assemblages and data subsetting. Our results are qualitatively robust to all sources of uncertainty. We contrast our spatially explicit results to the classical hypotheses proposed to explain the asymmetry in the proportion of immigrants at the regional scale. We advocate that the time for full expansion of immigrant ranges is a relevant aspect in structuring the spatial pattern of immigrants at the local scale but that interspecific interactions, climate and the difference between pools of temperate and tropical species might also be relevant and more explicitly incorporated in future studies of GABI's results at local scale.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112905"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684725","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":"Reconciling redox proxy contradiction with active FeMn shuttle in the Cryogenian Nanhua Basin of South China","authors":"Meng Cheng (程猛) ,&nbsp;Zihu Zhang ,&nbsp;Jun Hu ,&nbsp;Haiyang Wang ,&nbsp;Mengchun Cao ,&nbsp;Chao Li","doi":"10.1016/j.palaeo.2025.112899","DOIUrl":"10.1016/j.palaeo.2025.112899","url":null,"abstract":"<div><div>The Cryogenian Period is one of Earth's most critical time intervals for biological innovation and manganese (Mn) accumulation. The formation of the Mn ores in the Cryogenian Nanhua Basin (South China) has been attributed to early diagenesis with transient oceanic oxygenation evidenced by low C_org/P and high Ce/Ce*, but reconstruction of the ocean redox with Fe speciation revealed persistently anoxic water conditions in the basin. To address this disagreement, we conducted new δ³⁴S measurements of pyrite and carbonate-associated sulfate (CAS), together with bulk major and trace element compositions in three drill cores of the Datangpo Formation collected from the Nanhua Basin. The δ³⁴S values of both CAS and pyrite were significantly higher than the estimated seawater sulfate in the contemporary open ocean, likely reflecting the hydrographic restriction of the Nanhua Basin and a small sulfate reservoir size in the open ocean. Additionally, the superheavy δ³⁴S of pyrite is higher than its paired CAS, which can be best explained by partial oxidation of H₂S during the inflow of open ocean seawater, or the emission of volatile organosulfur, both indicating the bottom water was not fully oxygenated. Partial oxidation of H₂S might be caused by the episodic inflow of open ocean seawater, which would result in fluctuations in the depth of the chemocline, enhancing the activity of the Fe<img>Mn shuttle. The operation of Fe<img>Mn shuttle might adsorb P and Ce in shallow oxic waters, transport them to the deeper anoxic waters, and release them back into the water column. Therefore, we propose that the low C_org/P and positive Ce/Ce* in the Mn‑carbonates may indicate a stronger Fe<img>Mn shuttle effect rather than oxic water conditions. The contradictory results of different redox proxies in the Cryogenian Nanhua Basin thus can be reconciled with widespread anoxia in the open ocean, strong basin restriction, and episodic seawater inflow that caused enhanced Fe<img>Mn shuttle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112899"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682087","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":"Marine redox evolution and organic matter accumulation in the end Guadalupian in NE Sichuan, South China","authors":"Xiaotong Ge ,&nbsp;Baojian Shen ,&nbsp;Daizhao Chen ,&nbsp;Yali Liu ,&nbsp;Ziwen Jiang ,&nbsp;Mu Liu ,&nbsp;Xun Ge","doi":"10.1016/j.palaeo.2025.112901","DOIUrl":"10.1016/j.palaeo.2025.112901","url":null,"abstract":"<div><div>The Guadalupian-Lopingian (G-L) transition represents a pivotal interval, during which changes in oceanic redox conditions have been proposed to correlate with the end-Guadalupian mass extinction. However, the detailed spatial and temporal variations in marine redox states are still not well-defined. To explore the concurrent oceanic shifts and the factors controlling organic matter accumulation, we investigate an organic-rich succession from the G-L boundary located in an intrashelf basin in the northeastern Sichuan Basin, Southwest China by means of multiple geochemical indicators, including organic carbon isotope, total organic carbon contents, iron speciation contents, mercury contents and major and trace elements contents. Our results delineate four distinct intervals (I-IV) of redox conditions based on Fe-Mo-U-V data, showing a sequence from suboxic to ferruginous, followed by euxinic, and returning to suboxic conditions. The euxinic phase appears to have been driven by a highly restricted basin environment combined with frequent volcanic episodes. Additionally, the primary productivity peaked in the Interval II₂, which may have been a key factor in the organic matter accumulation. Comparative analysis with studies from other regions indicates that the Paleo-Tethys was more anoxic and exhibited greater stagnation than the Panthalassa during the end-Guadalupian, with the severity of anoxia during the Permian-Triassic transition surpassing that of the G-L transition. Overall, the significant marine anoxia was confined to moderate depths, with varying onset times across different areas, and was notably absent in the pelagic basins. This pattern implies that anoxia might not have been the primary cause of the mass extinction event.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112901"},"PeriodicalIF":2.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643944","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":"Neoproterozoic rift-related mafic and felsic rocks from the Yangtze Block, South China: Insights into petrogenesis and tectonic evolution","authors":"Jibiao Zhang ,&nbsp;Yanxue Liu ,&nbsp;Heng Zhang ,&nbsp;Chenglong Shi ,&nbsp;Peiwen Liu","doi":"10.1016/j.palaeo.2025.112904","DOIUrl":"10.1016/j.palaeo.2025.112904","url":null,"abstract":"<div><div>Neoproterozoic rift-related magmatism along the margins of the Yangtze Block presents a valuable opportunity to study the tectonic evolution of South China and the geodynamic processes resulting from the breakup of Rodinia. In this paper, we report Neoproterozoic rhyolites, diabases, and granites from the Kangdian and Nanhua Rift basins along the western and southeastern margins of the Yangtze Block, respectively. The Suxiong (ca. 819–824 Ma) and Yejia (ca. 800–804 Ma) rhyolites exhibit high Na₂O + K₂O (7.07–8.67 wt%) and Zr + Nb + Ce + Y (355–930 ppm) contents, zircon saturation temperatures (821–920 °C), and 10,000 × Ga/Al ratios (2.28–4.28), indicating an affinity with A-type granites. These rhyolites have depleted Nd<img>Hf isotopic compositions (ε_Hf(t) = +1.8 to +5.6 and ε_Nd(t) = +3.5 to +4.9, respectively) and are characterized by low Sr/Y (0.14–1.42) and (La/Yb)_N (3.98–9.1) ratios, Mg^# (8–35) values, and high Fe/(Fe + Mg) (0.76–0.96) ratios, suggesting that they were generated primarily by the partial melting of quartzofeldspathic crustal rocks under low-pressure, high-temperature conditions. The ca. 812 Ma Dengxiangying diabases are of the calc-alkaline series, showing enrichments in LILEs and LREEs and depletions in HFSEs. Isotoptic data (ε_Hf(t) = +6.6 to +10.1, ε_Nd(t) = +3.4 to +5.8) suggest that they were derived from the partial melting of subduction-modified lithospheric mantle. The ca. 810 Ma Yifeng granites display a weakly peraluminous character, with low zircon saturation temperatures (752–806 °C), and 10,000 × Ga/Al (2.0–2.6) and Zr + Nb + Ce + Y (155–340 ppm) values, similar to those of I-type granitoids. These granites have depleted whole-rock Nd (+1.5 to +2.6) and zircon Hf (+4.0 to +7.2) isotopic compositions, indicating derivation from the remelting of Mesoproterozoic mafic crustal materials. By integrating the petrogenesis of these Neoproterozoic rift-related rocks, we consider that the Kangdian Rift was a back-arc basin produced in response to the long-term slab subduction beneath the western Yangtze Block, whereas the Nanhua Rift was a continental rift basin produced in response to the upwelling of asthenospheric mantle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112904"},"PeriodicalIF":2.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685273","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":"Oceanic redox condition and the evolution of Ediacaran life: Evidence from nitrogen isotopes and biogenic silica in the Yangtze Block, South China","authors":"Zaiyun Wang ,&nbsp;Hansheng Cao ,&nbsp;Fajin Chen ,&nbsp;Kai Wei ,&nbsp;Chuang Bao ,&nbsp;Qinghua Hou ,&nbsp;Chunqing Chen ,&nbsp;Hanli Huang ,&nbsp;Qiuping Chen","doi":"10.1016/j.palaeo.2025.112903","DOIUrl":"10.1016/j.palaeo.2025.112903","url":null,"abstract":"<div><div>The late Ediacaran period witnessed the largest global carbon cycle disturbance in geological history, known as the “Shuram Excursion”, coinciding with the emergence of early complex multicellular life. While the rise in atmospheric and oceanic oxygen is seen as a major catalyst for this evolutionary leap, the link between oxygenation and Ediacaran diversification remains contested. To investigate this, we reported nitrogen, carbonate, and organic carbon isotopes, as well as biogenic silica (BSi) content from a drill core in the Yangtze Platform, South China. During the lower Shuram excursion, δ¹⁵N decreased from 5.9 ‰ to 2.9 ‰, suggesting a shrinking nitrate pool in the euphotic zone associated with intensified denitrification due to the expansion of the anoxic zone. During the middle Shuram excursion, a significant decline in δ¹³C_carb was accompanied by a rapid increase in δ¹⁵N (up to 5.8 ‰), which likely reflects a transitional redox state characterized by moderate denitrification in the water column, enriching the remaining nitrate in the photic zone with ¹⁵N. The subsequent decline in δ¹⁵N signatures likely reflects reduced water-column denitrification, driven by further ocean oxygenation and the deepening of the chemocline. The concurrent positive excursions in δ¹⁵N and negative δ¹³C_carb correspond to the peak in BSi contents, suggesting that the rise in seawater O₂ levels and the increase in surface nitrate concentrations provided a favorable environment for siliceous organisms. The geochemical signatures observed correspond with the diversification of ecologically important animal groups, emphasizing the accelerated evolution of the Avalon biota in oxygen and nitrate-enriched environments.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112903"},"PeriodicalIF":2.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643943","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 and lake ecosystem evolution over the last millennium on the north-eastern Tibetan Plateau: Insights from stable isotope records of gastropod shells in Xing Co","authors":"Yunqing Li ,&nbsp;Wanyi Zhang ,&nbsp;Siyao Liu ,&nbsp;Yanrong Zhang ,&nbsp;Xianyong Cao ,&nbsp;Fang Tian","doi":"10.1016/j.palaeo.2025.112896","DOIUrl":"10.1016/j.palaeo.2025.112896","url":null,"abstract":"<div><div>The evolution of alpine lake ecosystems on the north-eastern Tibetan Plateau (NETP) over the last millennium has been affected by climate change and human activity. This study reconstructs the palaeoclimate and lake productivity of Xing Co using carbon and oxygen isotopes from aquatic gastropod shells (<em>δ</em>¹³C_shell and <em>δ</em>¹⁸O_shell), grain-size, total organic carbon (TOC), total nitrogen (TN), and the TOC/TN (C/N) ratio. The highest lake productivity – during the Medieval Warm Period (MWP) – is likely linked to enhanced photosynthesis of aquatic plants and increased biomass within the lake. This increase was driven by warm, humid climate conditions, indicated by higher <em>δ</em>¹³C_shell values, lower <em>δ</em>¹⁸O_shell values, and increased coarse-grain content. In contrast, the significant decline in lake productivity during the Little Ice Age (LIA) resulted from deterioration of trophic status and restricted aquatic plant growth under colder, drier climate conditions. However, the decrease in lake productivity since 1950 CE, amid global warming, may be linked to increased soil erosion and sedimentation rate from intensified human activity and land-use changes. The combined effects of climatic shifts and human disturbances highlight the need for ongoing monitoring of lake ecosystems to understand their resilience and response to future environmental changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112896"},"PeriodicalIF":2.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643941","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":"Precipitation reconstruction for the western Chinese Loess Plateau since 1598 CE reveals recent wetting signals","authors":"Yue Li ,&nbsp;Feng Chen ,&nbsp;Xiaoen Zhao ,&nbsp;Weipeng Yue ,&nbsp;Mao Hu ,&nbsp;Junqiang Niu ,&nbsp;Tiyuan Hou ,&nbsp;Yang Xu ,&nbsp;Hechuan Wang ,&nbsp;Shijie Wang ,&nbsp;Honghua Cao ,&nbsp;Youping Chen ,&nbsp;Heli Zhang ,&nbsp;Max C.A. Torbenson","doi":"10.1016/j.palaeo.2025.112898","DOIUrl":"10.1016/j.palaeo.2025.112898","url":null,"abstract":"<div><div>Global warming has emerged as a significant environmental challenge for humanity, particularly in climate-sensitive regions such as the Chinese Loess Plateau (CLP). Climate changes in this region are thought to have led to an increase in extreme weather events, adversely affecting ecosystems and agricultural development. This study uses spruce tree-ring samples to reconstruct precipitation data for the western CLP (WCLP) since 1598 CE. The resulting record accounts for 49 % of the variation in instrumental precipitation from July of the previous year to June of the current year. Through this reconstruction, we document occurrences of extreme drought and wet events over the past 426 years, record significant historical drought events in WCLP, reveal climatic driving mechanisms on different timescales, and analyze recent trends of increasing precipitation. This study contributes to a deeper understanding of the climatic history of the WCLP and provides scientific foundations for future climate predictions and regional sustainable development.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112898"},"PeriodicalIF":2.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685359","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":"Meridional shifts of Brazil-Malvinas Confluence since the Last Glacial Maximum","authors":"Fang Gu ,&nbsp;Karin A.F. Zonneveld ,&nbsp;Hermann Behling","doi":"10.1016/j.palaeo.2025.112897","DOIUrl":"10.1016/j.palaeo.2025.112897","url":null,"abstract":"<div><div>The Brazil-Malvinas Confluence (BMC) is a highly dynamic convergence of surface currents in the southwestern South Atlantic, where the warm Brazil Current (BC) from the tropical Atlantic meets the cold Malvinas Current (MC) that originates from the northern branch of the Antarctic Circumpolar Current. Meridional shifts of the BMC play an important role in controlling the heat transfer from the tropical Atlantic to the higher latitudes of the South Atlantic. In this study, the marine core GeoB13861–1 is analyzed for pollen, spores, freshwater algae, and organic-walled dinoflagellate cysts (dinocysts) to reconstruct marine and terrestrial paleoenvironmental changes in southeastern South America since the Last Glacial Maximum (LGM). The results indicate that during LGM, the BMC was at its northernmost location due to the strong influence of the MC. During that period, exposed coastal areas of Argentina were dominated by salt marshes shaped by low global sea level. From ∼18 to 15 cal kyr BP, the BMC migrated southward, contributing to more humid conditions on the adjacent continent. As sea level rose, former salt marshes along the coast were gradually flooded. The increased presence of <em>Nothofagus</em> and <em>Podocarpus</em> pollen in the marine record suggests a slight expansion of Andean forests during the Late Glacial, indicating the adjacent continental regions shifted to wetter conditions. Notably, our study confirms that the signals of abrupt climate events, such as Heinrich Stadial 1 (HS1) and Younger Dryas (YD), are well-preserved in the marine sediment records. Our new findings provide clear evidence of the bi-polar sea saw effect during HS1, marked by abrupt ocean warming in the South Atlantic.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112897"},"PeriodicalIF":2.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643945","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 long-term dynamics of biodiversity and stability of the diatom community under climate warming in a Tibetan alpine lake","authors":"Yanjie Zhao ,&nbsp;Rong Wang ,&nbsp;Hengshuai Qiu ,&nbsp;Wenxiu Zheng ,&nbsp;Enlou Zhang ,&nbsp;Xiangdong Yang","doi":"10.1016/j.palaeo.2025.112882","DOIUrl":"10.1016/j.palaeo.2025.112882","url":null,"abstract":"<div><div>Remote lakes have been recognized as ideal monitors of global change as they are far from direct human intervention and can record the natural variabilities of lake ecosystems in their sediments. Over the past century, biodiversity losses and ecological regime shifts have been detected worldwide in the context of global warming. However, regions and biological communities are not studied equally in current research on biodiversity and stability, and high-elevation areas and aquatic micro-organisms are particularly underrepresented. This study explores Qudonglaco, an alpine lake above the treeline in the southeastern margin of the Tibetan Plateau, highlighting changes in its biodiversity and ecosystem stability in response to environmental drivers over the past two centuries. The study reconstructed terrestrial inputs from catchment and diatom community composition using paleolimnological proxies of geochemical elements and diatom assemblages, and calculated changes in species diversity and multifaceted stability over time. Under the impact of climate change, the lake environment changed dramatically after the 1990s, leading to a stark shift from tychoplanktonic-dominated to benthic-dominated community composition, accompanied by an almost doubling of species richness. Since 1975 CE, temporal stability has declined, with increased Jaccard similarity and network connectance, and reduced heterogeneity since the 1990s, signaling a decline in community resilience. Compared with the ecosystem development of arctic lakes between 1850 and 2000 CE, the 150-year beta diversity of diatom community in this region was smaller yet has continued to rise. The multidimensional changes of community stability and biodiversity should be considered when assessing the impacts of headwaters on the lower-reach ecosystems, and more monitoring and observation of remote ecosystems as well as a unifying framework for quantifying community stability from paleo-archives is needed.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112882"},"PeriodicalIF":2.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619904","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":"Calcareous plankton and shallow-water benthic biocalcifiers: Resilience and extinction across the Cenomanian-Turonian Oceanic Anoxic Event 2","authors":"Maria Rose Petrizzo ,&nbsp;Mariano Parente ,&nbsp;Francesca Falzoni ,&nbsp;Cinzia Bottini ,&nbsp;Gianluca Frijia ,&nbsp;Thomas Steuber ,&nbsp;Elisabetta Erba","doi":"10.1016/j.palaeo.2025.112891","DOIUrl":"10.1016/j.palaeo.2025.112891","url":null,"abstract":"<div><div>Oceanic Anoxic Event 2 (OAE 2), spanning the Cenomanian/Turonian boundary (93.9 Ma), was an episode of major perturbation of the global carbon cycle. Its geochemical signature is a synchronous positive δ¹³C excursion in both carbonates and organic matter that resulted from the net burial of large amounts of organic carbon in deep-sea and hemipelagic settings.</div><div>Causes for OAE 2 are still the subject of investigations; however, several studies postulate that massive submarine volcanic activity emitted greenhouse gases and provided biolimiting metals in marine ecosystems, leading to the onset of the Cenomanian-Turonian thermal maximum and to the enhancement of ocean fertility. Ocean temperature, sea-surface stratification, nutrient availability, and carbonate ion saturation were subject to variations during OAE 2 that resulted in fluctuations in diversity abundance and calcification of species.</div><div>We analyzed the record of the main biocalcifiers of pelagic-hemipelagic settings (planktonic foraminifera and calcareous nannofossils) and of low-latitude carbonate platforms (larger benthic foraminifera and rudist bivalves) by looking at well-dated sections. Carbon isotope stratigraphy allowed precise correlation from shallow to deep water and tied the biotic response to the record of geochemical proxies of paleoenvironmental changes. The main extinction event, severely affecting the shallow-water benthic biocalcifiers and to a minor extent the calcareous plankton, occurred within and after the Plenus Cold Event. Fluctuations in surface seawater temperature and extreme warming were probably the main cause of extinction, with contributions from decreased seawater carbonate saturation and disruption of ocean stratification. Overall, calcareous plankton fared much better, showing a greater resilience than carbonate-platform biocalcifiers to paleoenvironmental perturbations across OAE 2.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"668 ","pages":"Article 112891"},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}