Marine Micropaleontology最新文献

{"title":"Relative sea-level reconstructions by using foraminiferal transfer functions","authors":"Yvonne Milker","doi":"10.1016/j.marmicro.2024.102410","DOIUrl":"10.1016/j.marmicro.2024.102410","url":null,"abstract":"<div><div>Transfer functions, that use benthic foraminifera, are widely applied for reconstructions of changes in paleoenvironments such as relative sea-level changes and tectonic-induced vertical coastal motions. Such reconstructions are based on a representative modern training data sets, often sampled along the environmental gradient to be reconstructed. The species-environment relationships in a training data set can be modeled by using an adequate numerical technique, and the resulting transfer function model can then be applied to a fossil data set to reconstruct paleo-environmental conditions such as relative sea-level changes. Although transfer functions models are relatively easy to develop and to apply, several studies have shown that there are also difficulties with this approach. This study describes and discusses various aspects that should be considered when using the transfer function approach for relative sea-level estimates. It concentrates on the modern species-environment relations with a special focus on marine environments, describes widely used numerical methods for transfer function development, discusses several validation methods and addresses applications.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"192 ","pages":"Article 102410"},"PeriodicalIF":1.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Recent deep-sea nematodes and agglutinated foraminifera select specific grains and bioclasts from their environments: Ecological implications","authors":"Sunil K. Das ,&nbsp;Raj K. Singh ,&nbsp;Mariem Saavedra-Pellitero ,&nbsp;Julia Gottschalk ,&nbsp;Carlos A. Alvarez Zarikian ,&nbsp;Lester Lembke-Jene ,&nbsp;Frank Lamy ,&nbsp;Gisela Winckler ,&nbsp;Jennifer L. Middleton ,&nbsp;Helge W. Arz ,&nbsp;Chandranath Basak ,&nbsp;Anieke Brombacher ,&nbsp;Oliver M. Esper ,&nbsp;Jesse R. Farmer ,&nbsp;Lisa C. Herbert ,&nbsp;Shinya Iwasaki ,&nbsp;Vera J. Lawson ,&nbsp;Li Lo ,&nbsp;Elisa Malinverno ,&nbsp;Elisabeth Michel ,&nbsp;Xiangyu Zhao","doi":"10.1016/j.marmicro.2024.102409","DOIUrl":"10.1016/j.marmicro.2024.102409","url":null,"abstract":"<div><div>The high-latitude regions are known for a diverse array of benthic meiofauna, yet our understanding of these communities remains limited, particularly in the deep ocean. This study aims to assess the variability and adaptation of nematodes and agglutinated foraminifera in the modern sediments of the Southern Pacific Ocean at &gt;3500 m water depth. Seawater and sediment slurry from the first piston cores (i.e., mudline samples) from International Ocean Discovery Program Sites U1539, U1540, U1541, and U1543 were analyzed for Rose Bengal stained nematode and agglutinated benthic foraminifera. During the microscopic study seven nematode specimens belonging to the genus <em>Desmoscolex</em>, with 16–17, 36 or 38 main rings were found. Scanning electron microscopy study suggest that one morphotype with 17 main rings used only coccoliths of the species <em>Calcidiscus leptoporus</em> while the other specimens used fine-grained siliciclastic material on their concretion ring. Besides nematodes, a few benthic agglutinated foraminifera specimens exclusively used a single species of planktic foraminifera (<em>Globoconella inflata</em>) and/or robust coccoliths, in addition to other fine-grained siliciclastic material, for their test construction. These patterns appear to be highly selective. Specimens of the same benthic nematode <em>Desmoscolex</em> genus and agglutinated foraminifera that have diverse grain types show that these specimens can adapt to their environments, choose specific grains as per their preference, and have no relationship with the grain/particle abundance. This study of <em>Desmoscolex</em> and agglutinated foraminifera species suggests low to moderate organic matter flux and increased ventilation in the abyssal depth of the Southern Pacific Ocean.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"192 ","pages":"Article 102409"},"PeriodicalIF":1.5,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 3D images of sediment cores as powerful tool for exploring foraminiferal microhabitats","authors":"M.P. Nardelli ,&nbsp;N. Vanderesse ,&nbsp;M. Moller ,&nbsp;C. Guilhermic ,&nbsp;A. Mouret","doi":"10.1016/j.marmicro.2024.102394","DOIUrl":"10.1016/j.marmicro.2024.102394","url":null,"abstract":"<div><p>Benthic foraminifera are marine protists largely used as bioindicators and proxies of paleo- environments. Epifaunal species are supposed to live at or above the sediment surface and are therefore used as proxies for bottom water conditions, while infaunal inhabit the sediment column, thus tracing porewater chemistry. Traditional analytical methods based on core slicing, however, have a low resolution that does not allow to precisely characterise the preferential microhabitat(s) of indicator species.</p><p>In this study we performed microtomographic analyses on an experimental sediment core, to observe the life-position of living foraminifera of two surface-dwelling species <em>Ammonia confertitesta</em> and <em>Haynesina germanica</em>, reported both as epifaunal or shallow infaunal. The images we obtained offered for the first time the possibility to observe each individual in 3D space with a numerical resolution of 13 μm/voxel.</p><p>The results revealed that the two species are never located above or at the sediment surface and have their preferential microhabitats in a sub-superficial sediment layer constrained in the 0–500 μm interval below the surface. Rapid decrease of abundances below this layer suggests that their microhabitat could be even more specific than previously thought.</p><p>μCT-scan of sediment cores is also a valuable tool to obtain high-resolution information about foraminiferal ecology. The described method is useful to assess the effective microhabitat of all foraminiferal species that are usually used as proxies for paleorecords, to ensure that the information we can obtain from them is attributable to bottom water or to porewater conditions at a specific sediment depth.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"191 ","pages":"Article 102394"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377839824000641/pdfft?md5=827d2d5b8568a4649849315add7d5747&pid=1-s2.0-S0377839824000641-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Integrated record of the Late Lutetian Thermal Maximum at IODP site U1508, Tasman Sea: The deep-sea response","authors":"Irene Peñalver-Clavel ,&nbsp;Claudia Agnini ,&nbsp;Thomas Westerhold ,&nbsp;Marlow J. Cramwinckel ,&nbsp;Edoardo Dallanave ,&nbsp;Joyeeta Bhattacharya ,&nbsp;Rupert Sutherland ,&nbsp;Laia Alegret","doi":"10.1016/j.marmicro.2024.102390","DOIUrl":"10.1016/j.marmicro.2024.102390","url":null,"abstract":"<div><p>The Late Lutetian Thermal Maximum (LLTM) was a transient and brief global warming event recorded in the middle Eocene, at 41.52 Ma. The biotic response to the LLTM has been documented at only a few marine sites so far. Here, we present the first record of deep-sea benthic foraminiferal assemblage changes during the LLTM in the southwest Pacific at International Ocean Discovery Program Hole U1508C (1609 m water depth) in the Tasman Sea. The LLTM coincides with a negative excursion in bulk sediment δ¹³C (0.47‰) and benthic foraminifera δ¹³C (0.36‰), with changes in the relative abundance of benthic foraminiferal species and in the deep-water organic geochemistry. The decrease in diversity of the assemblages indicates environmental stress during the event, potentially linked to oxygen deficiency, as evidenced by the occurrence of dysoxic taxa (e.g. <em>Lenticulina</em> spp., <em>Turrillina brevispira)</em>. Although calcareous taxa dominate, the presence of corrosion-resistant species and poorly preserved foraminiferal tests suggest slightly CaCO₃-corrosive bottom waters, but no dissolution was evident. We suggest the shallowing of the thermocline and enhanced water column stratification at this site during the LLTM.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"191 ","pages":"Article 102390"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377839824000604/pdfft?md5=c97ff157181eed26d3abc24cece62484&pid=1-s2.0-S0377839824000604-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"A new fusulinid species from the early Permian of northwestern Peninsular Malaysia: Evidence of the Artinskian warming event in the eastern Peri-Gondwanan Sibumasu Block","authors":"Shirin Fassihi ,&nbsp;Daniel Vachard ,&nbsp;Petra Heinz ,&nbsp;Meor Hakif Amir Hassan ,&nbsp;Azrin Azmi","doi":"10.1016/j.marmicro.2024.102391","DOIUrl":"10.1016/j.marmicro.2024.102391","url":null,"abstract":"<div><p>A new species of <em>Crenulosepta</em>, i.e., <em>Crenulosepta perlisensis</em> Vachard and Fassihi sp. nov., is described from a Cisuralian (Lower Permian) sandy limestones and calcareous sandstones in the Kubang Pasu Formation in northwestern Peninsular Malaysia, which forms part of the Peri-Gondwanan Sibumasu Block. Previous Malaysian authors reported the occurrence of <em>Monodiexodina shiptoni</em> and <em>Monodiexodina sutschanica</em> from the same area. The findings of this study provide a better overview of the Cisuralian fusulinid fauna found in this region. The presence of <em>Crenulosepta</em> confirms that the age of the uppermost part of the Kubang Pasu Formation is Artinskian, rather than extending into the Kungurian as previously recognized. The uppermost part of the Kubang Pasu Formation with its impoverished genus and species diversity is located just above the cold water brachiopods and diamictite beds. It indicates that during the Asselian (earliest Cisuralian), the northwestern Peninsular Malaysia was still part of the Gondwana continental shelf. During the late Early Permian, northwestern Peninsular Malaysia, as part of the eastern Cimmerian Continent, was located in a low latitude subtropical region of the paleo-equatorial tropical Tethyan Realm. The microfacies analysis of the Kubang Pasu Formation suggests a very high-energy, warm shallow marine environment of the inner ramp (e.g., sand shoals and banks).</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"191 ","pages":"Article 102391"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling changes in the productivity regime during the Late Miocene-Early Pliocene Biogenic Bloom: Insights from the western equatorial Pacific (IODP Site U1488)","authors":"Maria Elena Gastaldello ,&nbsp;Claudia Agnini ,&nbsp;Thomas Westerhold ,&nbsp;Anna Joy Drury ,&nbsp;Laia Alegret","doi":"10.1016/j.marmicro.2024.102395","DOIUrl":"10.1016/j.marmicro.2024.102395","url":null,"abstract":"<div><p>The Late Miocene-Early Pliocene Biogenic Bloom (9.0–3.5 Ma) is a widespread paleoceanographic phenomenon marked by increased marine biological productivity and by high accumulations of biological components documented at multiple open ocean sites in the Indian, Pacific, and Atlantic oceans. We investigate the expression of the Biogenic Bloom at International Ocean Discovery Program (IODP) Site U1488 in the western equatorial Pacific Ocean. We generated an improved age model based on calcareous nannofossil biostratigraphy and a quantitative benthic foraminiferal record across the Late Miocene to the Early Pliocene. Increased carbonate mass accumulation rates suggest the Biogenic Bloom occurs between 8.1 and 4.0 Ma at Site U1488. We described four intervals with paleoenvironmental significance: Interval 1 (8.1–6.2 Ma), Interval 2 (6.2–5.5 Ma), Interval 3 (5.5–4.5 Ma), and Interval 4 (4.5–3.1 Ma), the Biogenic Bloom spans across Interval 1 and 3. Intervals 1, 3, and 4 are marked by high abundance of phytodetritus exploiting taxa, related to phases of El Niño-like conditions. The highest abundance of these species during Interval 1 has been related to a phase of higher seasonality. In contrast, intervals 3 and 4 show reduced seasonality and a steadier input of food to the seafloor, associated with increased dust supply through wind transport and/or increased continental weathering during the Pliocene. Interval 2 stands out as the sole interval encompassing La Niña-like conditions, marked by a shift in the nutrient composition reaching the seafloor, from labile phytodetritus to refractory organic matter, and possibly a decrease in seasonality.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"191 ","pages":"Article 102395"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377839824000653/pdfft?md5=b7c95e136f64e79cacef479e25f89677&pid=1-s2.0-S0377839824000653-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Multiple short-lived marine incursions into the interior of Southwest Gondwana during the Aptian","authors":"Gerson Fauth ,&nbsp;Oscar Strohschoen Jr. ,&nbsp;Simone Baecker-Fauth ,&nbsp;Fernanda Luft-Souza ,&nbsp;Marcos Antonio Batista dos Santos Filho ,&nbsp;Alessandra Santos ,&nbsp;Mauro Daniel Rodrigues Bruno ,&nbsp;Patrícia Mescolotti ,&nbsp;Guilherme Krahl ,&nbsp;Mitsuru Arai ,&nbsp;Francisco Henrique de Oliveira Lima ,&nbsp;Mario Luis Assine","doi":"10.1016/j.marmicro.2024.102389","DOIUrl":"10.1016/j.marmicro.2024.102389","url":null,"abstract":"<div><p>The Lower Cretaceous sediments of the Sanfranciscana Basin, southeast Brazil, are considered to have been deposited under a Gondwanan continental context. However, different authors have occasionally observed marine elements in these same deposits. This study analyzes samples from five sections of the Sanfranciscana Basin, Quiricó and Três Barras formations, to characterize the paleoenvironment around these marine incursions. We recovered continental (non-marine ostracods and palynomorphs) and marine microfossils (e.g., foraminifera, radiolarians, and ascidian spicules). The alternance of quartz-rich biogenic chert and claystone might be indicative of the occurrence of radiolarites in the studied sessions. The presence of the radiolarian genus <em>Turbocapsula</em> sp., the radiolarian species <em>H</em>o<em>locryptocapsa fallax</em>, and the palynomorph <em>Tucanopollis crisopolensis</em> enabled us to date the interval as early Aptian. Based on the lithologies and microfossils recovered, we interpreted the studied interval as a continental setting that was episodically subjected to marine incursions. We propose three successive paleoenvironmental scenarios: (1) an initial lacustrine depositional setting with a non-marine biota; (2) a second stage, characterized by the presence of episodic marine influence in the sedimentary succession (as evidenced by radiolarians, foraminifera and ascidians), and (3) the return to continental settings dominated by aeolian dune fields. These environmental scenarios characterize the initial development of the Central Segment of the South Atlantic Ocean.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"191 ","pages":"Article 102389"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141961846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing temporal transition between microgranular and hyaline tests of calcareous microplankton during the Late Jurassic","authors":"Diana Ölveczká ,&nbsp;Adam Tomašových ,&nbsp;Daniela Reháková ,&nbsp;Ján Schlögl ,&nbsp;Jozef Michalík","doi":"10.1016/j.marmicro.2024.102379","DOIUrl":"https://doi.org/10.1016/j.marmicro.2024.102379","url":null,"abstract":"<div><p>Calcareous microplankton increased in abundance during the latest Jurassic, coinciding with the increase in abundance of calcareous nannofossils and with the onset of deposition of pelagic calcareous oozes. However, the timing and causes of the shift from microgranular tests of the earliest microplankton (chitinoidellids) to hyaline tests of calpionellids are obscured because the ultrastructure of two-layered praecalpionellids that occur during the Tithonian is poorly documented. Here, we investigate the ultrastructure of chitinoidellids and praecalpionellids from Upper Tithonian deposits in the Western Carpathians. We show that (1) the chitinoidellid microgranular layer is formed by elongated, euhedral, densely-packed, nanometric needles rather than by fragments of calcareous nannofossils, (2) two-layered chitinoidellids (<em>Semichitinoidella</em>) are formed by an internal microgranular layer (identical to that of <em>Chitinoidella</em>) and by an external hyaline prismatic layer, and (3) two-layered <em>Praetintinnopsella</em> exhibits an internal hyaline layer (with densely-packed, equant microcrystals) and an external layer formed by a dark organic rim. The external layer in <em>Praetintinnopsella</em> thus does not have any relation to the microgranular layer in chitinoidellids and the external hyaline layer of <em>Semichitinoidella</em> is not equivalent in structure to the hyaline layer of <em>Praetintinnopsella</em>. As both single-layer and two-layered chitinoidellids appear prior to the first appearance of <em>Praetintinnopsella</em> but still co-occur with this genus in the lowermost Upper Tithonian deposits, the origin of two-layered <em>Praetintinnopsella</em> either reflects a major transformation in biomineralization towards larger and more packed crystals during their earlier divergence from the chitinoidellid lineage or an origination of two-layered tests with a hyaline layer from an independent non-chitinoidellid ancestor.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"190 ","pages":"Article 102379"},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolutionary change of crystallographic orientation and coccolith morphology: Neogene-Quaternary Umbilicosphaera (Prymnesiophyceae) lineage","authors":"Masayuki Utsunomiya ,&nbsp;Toshihiro Kogure","doi":"10.1016/j.marmicro.2024.102370","DOIUrl":"https://doi.org/10.1016/j.marmicro.2024.102370","url":null,"abstract":"<div><p>The crystallographic orientation and its relationship to the morphology of coccoliths were investigated for the Neogene-Quaternary calcareous nannoplankton <em>Umbilicosphaera</em> lineage using scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The <strong>c</strong>-axis of the calcite forming the distal shield elements was inclined upward at 66–68° (<em>U. sibogae</em>), 65–68° (<em>U. foliosa</em>), 57–58° (<em>U. rotula</em>), and 55–57° (<em>U. patera</em>) from the coccolith plane. Accordingly, the outward dip angle of one of the {<span><math><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>4</mn></math></span>} faces forming the surface of the distal shield of <em>U. patera</em> coccolith was shallower than those of <em>U. sibogae</em> and <em>U. foliosa</em>, explaining the nearly flat distal shield and the steep inner slope, formed by another equivalent {<span><math><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>4</mn></math></span>} face, around the central opening of <em>U. patera</em>. Our results showed that the evolution from <em>U. rotula</em> to <em>U. patera</em> during the Late Miocene was not accompanied by a change in crystallographic orientation. In contrast, the evolution from <em>U. patera</em> to <em>U. sibogae</em> and <em>U. foliosa</em> during the Pliocene was accompanied by a rotation of the orientation. The crystallographic orientation of calcite nuclei on the baseplate with a combination of other factors would have resulted in species-specific differences in shield shape and suture lines within the same phylogeny, consequently producing morphological diversity in the coccolith throughout geological time.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"190 ","pages":"Article 102370"},"PeriodicalIF":1.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141242143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling ecological signals related to the MECO onset through planktic and benthic foraminiferal records along a mixed carbonate-siliciclastic shallow-water succession","authors":"Antonella Gandolfi ,&nbsp;Victor Manuel Giraldo-Gómez ,&nbsp;Valeria Luciani ,&nbsp;Michele Piazza ,&nbsp;Valentina Brombin ,&nbsp;Simone Crobu ,&nbsp;Cesare Andrea Papazzoni ,&nbsp;Johannes Pignatti ,&nbsp;Antonino Briguglio","doi":"10.1016/j.marmicro.2024.102388","DOIUrl":"10.1016/j.marmicro.2024.102388","url":null,"abstract":"<div><p>The shallow-water Capo Mortola succession (Liguria, NW Italy) yields diverse assemblages of smaller benthic and planktic foraminifera, larger benthic foraminifera (LBF), and calcareous nannofossils. With the aim of improving the understanding of the Middle Eocene Climatic Optimum (MECO) impact on the shallow-water marine biotic communities due to global warming, we provide biostratigraphic and stable isotope data to achieve a reliable stratigraphic constraint of the MECO. The correlation of the stable isotope oxygen data with datasets of similar age from other regions suggests that only the onset of the MECO interval is recorded in the Capo Mortola section. Quantitative analyses of smaller benthic foraminiferal assemblages indicate that the shallow-water setting of Capo Mortola was not particularly affected by the onset of the MECO perturbance because no variation in nutrient supply or oxygen level were detected. A different scenario is recorded by the LBF genera <em>Operculina</em> and <em>Discocyclina</em>, which increased in abundance across the MECO onset, probably due to a rise in temperature and adapting to the increase in nutrient supply. In the upper water column, the variations in calcareous plankton communities appear to be controlled by both the MECO warming and a moderate increase in eutrophic conditions related to the enhanced hydrological cycle. Nutrients, mostly consumed in the upper water column, reached the seafloor in a limited amount, as benthic foraminifera record a meso-oligotrophic environment across the studied MECO interval.</p></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"190 ","pages":"Article 102388"},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377839824000586/pdfft?md5=ecfb46cdef8d0093e7374bc6c271258c&pid=1-s2.0-S0377839824000586-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}