Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Spatial differences in Holocene peat and carbon accumulation rates in three peatlands in the permafrost region of Altai Mountains, Northwestern China","authors":"Yan Zhang ,&nbsp;Xiaohui Chen ,&nbsp;Ping Yang ,&nbsp;Chuanyu Gao ,&nbsp;Chuan Tong ,&nbsp;Philip A. Meyers","doi":"10.1016/j.palaeo.2025.112879","DOIUrl":"10.1016/j.palaeo.2025.112879","url":null,"abstract":"<div><div>Peatlands in northern permafrost regions contain large carbon pools that are sensitive to regional and global factors. Considerable uncertainty remains about the potential impacts of global climate change on the processes important to peat C accumulation, especially in permafrost regions. In this study, peat cores from three different peatlands in the permafrost region in Xinjiang Altai Mountains of northwestern China were investigated to explore their peat properties and carbon accumulation histories. The results show that peat initiation ages, peat properties and carbon accumulation rates differed in the three different localities, caused by differences in topography, local climate, and permafrost changes. Moreover, we find that unlike the variations of Holocene C accumulations in non-permafrost peatlands, Holocene mean peat carbon accumulation rate (CAR, mean 35.5 ± 10.7 (SD) g C/m²/yr) in the permafrost region is higher than Holocene CAR values (mean 25.4 ± 7.7 (SD) g C/m²/yr) in non-permafrost peatlands, and had higher CARs before 6.5 cal. Kyr BP with continuous decreases from 6.5 to 2.0 cal. Kyr BP, and higher values during the late Holocene. Although these variations are like other northern peatlands, they share different driving mechanisms in long-term peat carbon accumulation. We postulate that under the background of continuous warming related to increasing 50°N winter solar radiation, changes in vegetation type associated with permafrost thawing have had a central role in determining long-term peat and carbon accumulation rates in the permafrost regions in the Altai Mountains.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112879"},"PeriodicalIF":2.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579025","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":"Dynamics of arid desert coastal ecosystem in response to tsunami, tropical cyclone, and drought: A pollen and geochemical study from Baja California Sur, Mexico","authors":"Qiang Yao ,&nbsp;Kam-biu Liu ,&nbsp;Alejandro Antonio Aragón-Moreno ,&nbsp;Erika Rodrigues ,&nbsp;Marcelo Cohen ,&nbsp;Shubo Fang","doi":"10.1016/j.palaeo.2025.112877","DOIUrl":"10.1016/j.palaeo.2025.112877","url":null,"abstract":"<div><div>The long-term ecological responses to natural disturbances in arid desert coastal ecosystems are crucial for understanding and predicting ecosystem dynamics, yet there is a notable scarcity of studies addressing these responses in such regions. Through microfossil and geochemical analyses of sediment cores from Lake Santispac and Lake Cocos, we exam the impacts of tsunamis, tropical cyclones, and droughts on vegetation dynamics and biodiversity in Baja California sur. Our findings reveal critical insights aligned with the Intermediate Disturbance Hypothesis (IDH). Tropical cyclones, acting as intermediate disturbances, enhance biodiversity by creating habitat heterogeneity, while extreme events like tsunamis reset ecological stages, facilitating species colonization and boosting biodiversity. Conversely, prolonged droughts reduce biodiversity by favoring drought-tolerant species. Future climate projections indicate higher temperatures, more frequent intense tropical cyclones, and prolonged droughts, further influencing these dynamic ecosystems. Mangroves, essential for maintaining biodiversity and ecosystem resilience, are expected to expand due to increased storm activity and sediment deposition. However, the combined effects of these disturbances create a nonequilibrium state, fostering high biodiversity and resilience in Baja California's ecosystems. Additionally, evidence of historical human activities, such as cave arts and arrow artifacts, underscores the importance of further study into human-environment interactions in this region. This study highlights the significance of long-term paleoecological studies in deciphering ecosystem dynamics and provides a crucial foundation for future research aimed at unraveling the complex dynamics of disturbances in maintaining biodiversity and ecosystem health in arid coastal regions, emphasizing the vital role of palynology in understanding ecosystem transformations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112877"},"PeriodicalIF":2.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593443","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":"Provenance and environmental changes recorded in Holocene sediments from the Southern Yellow Sea, China","authors":"Shuhuan Du ,&nbsp;Rong Xiang ,&nbsp;Xiang Su ,&nbsp;Jianguo Liu ,&nbsp;Shengfa Liu ,&nbsp;Zirui Pan ,&nbsp;Chuanxiu Luo ,&nbsp;Fuchang Zhong ,&nbsp;Li Fang","doi":"10.1016/j.palaeo.2025.112861","DOIUrl":"10.1016/j.palaeo.2025.112861","url":null,"abstract":"<div><div>Marine sediments in marginal seas serve as valuable archives of provenance and environmental changes. In this study, we investigate high-resolution Holocene variations in carbonate content using bulk samples and different particle sizes of carbonate distribution. Our analysis integrates benthic foraminiferal abundances, detrital minerals, and stable carbon and oxygen isotopic compositions from a well-dated sediment core, C02 (34°59.89΄N, 122°0.03΄E; water depth 52.5 m), in the southern Yellow Sea mud deposits. The bulk sample analysis reveals three distinct phases of sedimentation over the past 11.2 ka BP. The highest sediment carbonate content (averaging 4.53 %) occurred during the early Holocene. The majority of carbonate (about 80 %) is found in the &lt;38 μm grain size fraction, indicating an offshore environment during stage III (11.2–10.1 ka BP) characterized by low coastal saline benthic foraminifera assemblages. In stage II (10.1–6.5 ka BP), the contribution of carbonate from the &lt;38 μm grain size fraction decreased to 60 %, suggesting a slight decrease in sediment supply from the Yellow River but an increase compared to the Yangtze River. Stable carbon and oxygen isotopic compositions of benthic foraminifera support this. Additionally, our study has revealed that benthic foraminifera abundance increased during two peaks around 9 ka and 7.3 ka BP, corresponding to abrupt sea level rises during meltwater pulses (MWP)-1C and MWP-1D, respectively. During stage I (6.5–4 ka BP), sea level approached modern levels, and a modern-day circulation pattern was established. A period of non-deposition occurred over the last 4 ka BP, possibly linked to hydrological changes driven by the East Asian monsoon. The carbonate content, especially in different particle size fractions of the sediment, offers valuable insights into Holocene environmental evolution in marginal seas. These findings are crucial for understanding the paleoenvironmental history of the Yellow Sea and past global changes, underlining the significance of our study.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112861"},"PeriodicalIF":2.6,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551583","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":"Mg/Ca and Sr/Ca ratios of Limnocythere inopinata ostracod valves from the Badain Jaran Desert, Northwest China and their implications for paleoenvironmental reconstruction","authors":"Gaolei Jiang ,&nbsp;Linjing Liu ,&nbsp;Xin Mao ,&nbsp;Zhongshuang Cheng ,&nbsp;Zhe Wang ,&nbsp;Meng Li ,&nbsp;Nai'’ang Wang","doi":"10.1016/j.palaeo.2025.112868","DOIUrl":"10.1016/j.palaeo.2025.112868","url":null,"abstract":"<div><div>The trace element composition, especially the Mg/Ca and Sr/Ca ratios, of ostracod valves are commonly used as proxies for paleoenvironmental reconstruction; however, the effects of hydrochemical parameters on these compositions remain uncertain. In this study, we report Mg/Ca_valve and Sr/Ca_valve ratios of <em>Limnocythere inopinata,</em> a common and eurytopic ostracod species in the Holarctic, and corresponding water chemistry data from 21 lakes in the Badain Jaran Desert of Northwest China. These selected lakes are distributed in close proximity and have similar water temperatures, allowing us to analyse the influences of water chemistry on the valve partition coefficients separately. The results show that Sr/Ca_valve ratio has a good linear correlation with Sr/Ca_water ratio and that <em>K</em>_d[Sr] is little affected by hydrochemical parameters. These results indicate that Sr enters ostracod valves via isomorphism (a certain proportion of Ca²⁺ in low-Mg calcite crystals is replaced by Sr²⁺). Mg/Ca_water and alkalinity are the two main factors affecting the <em>K</em>_d[Mg] of <em>L. inopinata</em> valves. Increases in the Mg/Ca ratio and alkalinity of host water enhance the calcification of valves, which leads to a decrease in the proportion of organic matter in ostracod valves. This process is not conducive to the preservation of Mg in ostracod valves. In addition, comparative analysis of the data from different areas indicated that the <em>K</em>_d[Mg] and <em>K</em>_d[Sr] values of <em>L</em>. <em>inopinata</em> valves have similar relationships with hydrochemical parameters in different areas, which is favourable for reconstructing the paleoenvironment by using the trace element compositions of <em>L. inopinata</em> valves.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112868"},"PeriodicalIF":2.6,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551586","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 environmental magnetic study of a paleosol from the upper Permian in Southwest China, and its paleoclimatic implications","authors":"Rongyao Ma ,&nbsp;Yan Liu ,&nbsp;Jianbo Chen ,&nbsp;Zhuang Xiao ,&nbsp;Jinhua Li ,&nbsp;Zhuo Feng","doi":"10.1016/j.palaeo.2025.112839","DOIUrl":"10.1016/j.palaeo.2025.112839","url":null,"abstract":"<div><div>Paleosols are ancient soils that are formed in non-marine environments and contain valuable information about past climates and environmental changes. They have been extensively studied around the world as paleoclimatic indicators for the Earth's history. However, the systematic study of paleosols from the upper Permian and their corresponding paleoclimatic implications remain poorly understood. In this study, we systematically investigated the rock magnetic and microscopic features of an oxisol bed (∼5.07 m thick) from the upper Permian in Southwest China. Analyses on both outcrop and drill core samples show that the oxisol bed exhibits a systematic lithological transition from the dusky red mudstone in the saprolite subzone to grayish-green and reddish-brown mottled sandy mudstone and silty mudstone in the mottled subzone. In the saprolite subzone, the mineral crystal size is relatively smaller and poorly preserved, and the magnetic-carrying minerals are comprised of abundant micron- and submicron-sized magnetite particles. By contrast, in the mottled subzone, the mineral crystal size (such as quartz) is relatively larger and well-preserved, and the magnetic-carrying minerals are dominated by abundant micron- and submicron-sized hematite particles. High-resolution environmental magnetic analyses suggest that the saprolite subzone was formed in relatively warm and humid conditions with enhanced physical weathering, while the mottled subzone was formed under short-term paleoclimatic events characterized by high temperatures and enhanced chemical weathering. This study represents the first systematic magnetic and microscopic characterizations of paleosols from the upper Permian in Southwest China, shedding new light on the paleoclimatic conditions at the time.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112839"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551486","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":"Orbital-millennial-centennial evolution of paleoceanography and sea ice in the northwestern Pacific during the LGM-Holocene inferred from micropaleontological, geochemical and lithological proxies","authors":"S.A. Gorbarenko ,&nbsp;A.V. Artemova ,&nbsp;O. Yu Psheneva ,&nbsp;N.K. Vagina ,&nbsp;X. Shi ,&nbsp;A.A. Bosin ,&nbsp;Yu P. Vasilenko ,&nbsp;Z. Yao ,&nbsp;Y. Liu ,&nbsp;E.A. Yanchenko ,&nbsp;Yu V. Novoselova ,&nbsp;J. Zou","doi":"10.1016/j.palaeo.2025.112862","DOIUrl":"10.1016/j.palaeo.2025.112862","url":null,"abstract":"<div><div>Species distribution in diatom, benthic foraminifera (BF), pollen assemblages and geochemical and lithological proxies, derived from sediment core off the Southeastern Kamchatka, were used for millennial-centennial reconstruction of environment and sea ice condition of the northwestern (NW) Pacific and Kamchatka Peninsula over the Last Glacial Maximum (LGM)-Holocene. According to diatom and BF species distribution during the LGM and Heinrich Stadial 1(HS 1), near-closed winter sea ice conditions off Southern Kamchatka indicate intense sea ice formation in the Bering Sea and NW Pacific. At the onset of Bølling warming paleontology results show remarkable retreat of sea ice off south Kamchatka coeval with reduced formation and shoaling of North Pacific Intermediate Water (NPIW), accompanied by uplifting of upper boundary of the north Pacific deep water, enriched with nutrients and CO₂. Coeval increase of CaCO₃ and chlorin content suggest regional supply of CO₂ and nutrients from deep water to subsurface water of subarctic Pacific, accompanied by abrupt rise of primary productivity. The trees vegetation in the Kamchatka began spread only since the late Older Dryas cooling in response to Peninsula climate changes. During the Allerød warming, the regional environment fluctuated with a slight increase in sea ice's influence according to the diatom and BF species. Over the Younger Dryas BF and diatom species indicated cooling of surface water environment, especially after 12.3 ka BP. The moss and fern vegetation of the Kamchatka coastal lowland respond to onset of Holocene warming over a few centuries, whereas trees had a succession of 1–2 millennia. The regional environment during the Holocene was punctuated by four centennial cold events.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112862"},"PeriodicalIF":2.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611510","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":"From local to regional: Assessing the spatial extent and regional representativeness of Holocene mollusc assemblages in Central Europe","authors":"Kateřina Kubíková ,&nbsp;Michal Horsák ,&nbsp;Lucie Juřičková","doi":"10.1016/j.palaeo.2025.112865","DOIUrl":"10.1016/j.palaeo.2025.112865","url":null,"abstract":"<div><div>Terrestrial mollusc assemblages are an important Quaternary proxy due to their local deposition and their usefulness for detailed habitat reconstruction; however, it is uncertain whether single or limited number of assemblages provide reliable information about larger spatial scales. In this paper, we report Holocene mollusc assemblages from four regions of Central Europe to determine the number of profiles required for a reliable assessment of past regional biodiversity. The study regions span a range of different geomorphological and environmental conditions, and show varied histories of human impact. For each study region, we examined the proportion of the modern species pool represented by different numbers of Holocene profiles. Our results indicate that while a single Holocene profile captures a significant proportion of local diversity, multiple profiles are required for broader regional studies or palaeoecological reconstructions. In addition, we assessed the spatial extent that a single Holocene profile most accurately represents by comparing the assemblages recorded in the profile with modern communities at varying distances from the profile. Our findings show that the profiles are generally most representative of areas within a few kilometres. However, this distance is significantly influenced by local topography, which is reflected in the size of the profile catchment area.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112865"},"PeriodicalIF":2.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550453","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":"Niche exploitation profiles predict the palaeoclimate of tropical mammal communities","authors":"Kris Kovarovic ,&nbsp;Kari Lintulaakso","doi":"10.1016/j.palaeo.2025.112860","DOIUrl":"10.1016/j.palaeo.2025.112860","url":null,"abstract":"<div><div>There are multiple ways in which fossil mammal communities can be used to reconstruct palaeoenvironments, but their relationship to paleoclimate conditions is less clear. In this study, we used a database of mammal species present at 167 modern localities across the tropical zone to construct niche profiles in which each taxon is assigned to a locomotor and diet behaviour category. Cluster analysis identifies significantly different groups of localities on the basis of these profiles, driven by their relative proportion of terrestrial herbivores, terrestrial animalivores, arboreal frugivores, and terrestrial frugivores. These groups are shown to vary according to climate, particularly to aspects of precipitation. We added three Plio-Pleistocene fossil localities to our analytical model to reconstruct their palaeoclimates based on their niche exploitation profiles: Esquina Blanca (Uquía Formation), Argentina, Laetoli, Tanzania, and Thum (Tham) Wimam Nakim (Snake Cave), Thailand. In accordance with independent studies, we show Esquina Blanca to have had a low rainfall and seasonal climate and Laetoli a moderately low rainfall climate. Thum Wimam Nakim falls in a moderate rainfall, moderate temperature climate cluster, but is likely to be a non-analog community.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112860"},"PeriodicalIF":2.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550454","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}

{"title":"Climate change regulated carbonate production and accumulation in the Guaymas Basin over the past ca. 450,000 years","authors":"Hong Peng ,&nbsp;Yuchen Zheng ,&nbsp;Meng Zhou ,&nbsp;Yasu Wang ,&nbsp;Lihua Ran ,&nbsp;Han Jiang ,&nbsp;Ligia Pérez-Cruz ,&nbsp;Rafael Venegas ,&nbsp;Tobias Höfig ,&nbsp;Andreas Teske ,&nbsp;Daniel Lizarralde ,&nbsp;Kathleen Marsaglia ,&nbsp;IODP Expedition 385 Scientist ,&nbsp;Ying Cui ,&nbsp;Shijun Jiang","doi":"10.1016/j.palaeo.2025.112864","DOIUrl":"10.1016/j.palaeo.2025.112864","url":null,"abstract":"<div><div>Middle Pleistocene–Holocene sediment sequences were obtained during International Ocean Discovery Program Expedition 385 in the Guaymas Basin. However, the age model is not well constrained due to a lack of stratigraphic datums and suitable dating approaches for this time interval. In this study, we analyzed the sedimentary carbonate content (wt% CaCO₃) from Site U1546 as a proxy for biogenic carbonate production and compared it with the LR04 global benthic δ¹⁸O stack. The identification of 12 marine isotope stages from 21 correlation tie points establishes a refined chronology for the middle Pleistocene–Holocene sequence in the Guaymas Basin, and enables us to date the upper 354 m sediments back to ∼450 thousand years (kyr). Our data showed a broad range of wt% CaCO₃ values, from ∼0 % to 64.1 %, with an average of ∼16.7 %. The relatively low carbonate contents are primarily attributed to the dominance of siliceous diatoms over calcifying coccolithophores under eutrophic conditions, and organic matter remineralization further reduces carbonate preservation. Additionally, our research underscores higher wt% CaCO₃, linear sedimentation rates, and carbonate accumulation rates during interglacials compared to glacial periods, likely due to the preference of carbonate-producing coccolithophores for warmer temperatures. This suggests that climate change may have been the driver of the variation pattern of sedimentary carbonate content in the Guaymas Basin over the past ∼450 kyr. This study not only provides a refined chronology at multi-millennial time scale but also contributes critical data for cross-Pacific correlation with the Asian continental margins, enhancing the understanding of interactions between various climatic and oceanic processes on both regional and global scales.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"666 ","pages":"Article 112864"},"PeriodicalIF":2.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550487","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":"Foraminiferal assemblages from the Toarcian (Lower Jurassic) ‘Spotted limestone’ of the northern Adriatic Carbonate Platform","authors":"Luka Gale ,&nbsp;Rok Brajkovič ,&nbsp;Adrijan Košir","doi":"10.1016/j.palaeo.2025.112841","DOIUrl":"10.1016/j.palaeo.2025.112841","url":null,"abstract":"<div><div>The present study provides an in-depth study of foraminiferal assemblages from a Tethyan carbonate platform during the late Early Jurassic interval of environmental perturbations. The Toarcian succession from the Adriatic Carbonate Platform was investigated in two sections from Slovenia. In addition to detailed sedimentological and micropalaeontological analysis, carbon and oxygen isotope curves were produced. The succession starts with platform-top facies with abundant and diverse skeletal material, including lithiotid and megalodontid bivalves, dasycladacean algae, corals and sponges. Foraminifera are diverse and abundant, with larger benthic foraminifera (LBF) being the most commonly present. The shallow platform facies is followed by dark grey allodapic limestone, suggesting the formation of an intraplatform basin with restricted circulation of bottom waters. The composition of the transported material highlights the continuation of biotic carbonate production in the shallower parts of the platform. Deposition of the overlying ‘Spotted limestone’, thin-bedded laminated and bioturbated carbonate mudstone coincides with the negative carbon isotope excursion and the onset of the Toarcian Oceanic Anoxic Event (T–OAE). Foraminifera are represented by small lagenids and opportunists. No LBF were detected, and barren intervals are common. With the gradual return of carbon isotope values to less negative values, ooids and bioclasts are once again transported into the basin. The abundance and diversity of foraminifera return to pre-excursion levels, although with fewer species of LBF. The lower diversity of LBF could be related to environmental stress that affected the shallower parts of the platform during T–OAE, such as sea water warming and/or eutrophication.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"667 ","pages":"Article 112841"},"PeriodicalIF":2.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562229","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}