Marine Micropaleontology最新文献

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Sessile foraminifera from mobile substrates: Hidden organisms and big mistakes – The essential is invisible to the eyes 来自移动基质的无孔有孔虫:隐藏的生物体和大错误-本质是肉眼看不到的
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-02-15 DOI: 10.1016/j.marmicro.2025.102450
Joicce Dissenha , Sibelle Trevisan Disaró , José Rodolfo Angulo , Rodrigo Aluizio
{"title":"Sessile foraminifera from mobile substrates: Hidden organisms and big mistakes – The essential is invisible to the eyes","authors":"Joicce Dissenha ,&nbsp;Sibelle Trevisan Disaró ,&nbsp;José Rodolfo Angulo ,&nbsp;Rodrigo Aluizio","doi":"10.1016/j.marmicro.2025.102450","DOIUrl":"10.1016/j.marmicro.2025.102450","url":null,"abstract":"<div><div>Two case studies conducted on the inner continental shelf off southeastern Brazil revealed an unexpectedly high abundance and diversity of foraminifera attached to or encrusted in sediment grains. Samples were stained with Rose Bengal, fixed in formalin, and subjected to trichloroethylene flotation to isolate free foraminifera. Following screening, the residual fraction was rigorously examined, uncovering numerous attached individuals and robust agglutinate forms that incorporate sediment grains into their tests. This fauna includes little-known genera rarely documented in unconsolidated mobile substrates. Comparisons between floated and residual fractions revealed notable discrepancies, emphasizing the underestimation of sessile and robust forms when residual fractions are overlooked. Neglecting these forms can compromise environmental and paleoenvironmental interpretations, as rarefaction curves illustrate, particularly in high-hydrodynamic regions typically seen as challenging environments for fauna. This study underscores the importance of including sessile foraminifera in biodiversity assessments in dynamic marine areas. We propose a new zone, the “high-hydrodynamic inner coastal shelf,” for Murray's (1973) ternary diagram. Additionally, our findings indicate that inadequate screening methods may leave significant gaps in taxonomic records. Many attached foraminifera remain “invisible to the eye” of researchers, often due to their shape, a lack of prior knowledge, or insufficient attention, resulting in underestimations of their density and richness. Consequently, these organisms are often overlooked in environmental characterizations, taxonomic records, and especially in paleoecological studies and monitoring efforts.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102450"},"PeriodicalIF":1.5,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463598","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}
引用次数: 0
Dinoflagellate cyst assemblages in recent sediments of Iran's tropical mangrove forests 伊朗热带红树林近期沉积物中的鞭毛藻囊组合
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-02-08 DOI: 10.1016/j.marmicro.2025.102449
Gilan Attaran-Fariman , Sima Abir , Faezeh Dolatabadi , Ehsan Abedi , Fatemeh Sayareh
{"title":"Dinoflagellate cyst assemblages in recent sediments of Iran's tropical mangrove forests","authors":"Gilan Attaran-Fariman ,&nbsp;Sima Abir ,&nbsp;Faezeh Dolatabadi ,&nbsp;Ehsan Abedi ,&nbsp;Fatemeh Sayareh","doi":"10.1016/j.marmicro.2025.102449","DOIUrl":"10.1016/j.marmicro.2025.102449","url":null,"abstract":"<div><div>We investigated the distribution and composition of dinoflagellate cysts, including potential harmful algal bloom (HAB) species, in Iranian mangroves bordering the Persian Gulf and Oman Sea. Sediment samples were collected from 62 stations across 10 locations in three provinces (Bushehr, Hormozgan, Sistan &amp; Baluchestan) in autumn 2020. Analysis of dinoflagellate cysts revealed a diverse assemblage encompassing 56 species, including 10 known to be triggers of harmful algal blooms (HABs). Genus <em>Protoperidinium</em> was dominant, exhibiting a 21.4 % abundance and comprising 14 species across 60 sampling stations. In contrast, genus <em>Margalefidinium</em> was present in 34 stations with only a single species. <em>Margalefidinium polykrikoides</em> was the key species of dissimilarity between provinces, driving distinct compositions in all pairwise comparisons. <em>Scrippsiella acuminata</em> was a significant contributor to the dissimilarity observed between the Bu and S&amp;B, as well as the Ho and S&amp;B assemblages. DistLM, dbRDA, and marginal tests confirmed that environmental parameters significantly (<em>P</em> &gt; 0.05) influenced cyst composition across the provinces. Regular monitoring of environmental parameters alongside analyses of dinoflagellate cyst assemblages is a potential use for predicting HABs and also provide valuable insights into the well-being of essential mangrove ecosystems.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102449"},"PeriodicalIF":1.5,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378431","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}
引用次数: 0
Orbital-scale biotic and paleoceanographic changes in Japan Sea during the late Miocene global cooling (LMGC) 晚中新世全球变冷(LMGC)期间日本海生物和古海洋学的轨道尺度变化
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-28 DOI: 10.1016/j.marmicro.2025.102448
Mizuki Tojima , Masayuki Ikeda , Kenji M. Matsuzaki
{"title":"Orbital-scale biotic and paleoceanographic changes in Japan Sea during the late Miocene global cooling (LMGC)","authors":"Mizuki Tojima ,&nbsp;Masayuki Ikeda ,&nbsp;Kenji M. Matsuzaki","doi":"10.1016/j.marmicro.2025.102448","DOIUrl":"10.1016/j.marmicro.2025.102448","url":null,"abstract":"<div><div>The late Miocene global cooling (LMGC; ca. 7.9–5.8 Ma) was accompanied by global environmental changes including monsoon intensity, ocean circulation, and biotic turnover. Recent studies have revealed drastic environmental and biotic changes in the Japan Sea across the LMGC; the radiolarian fauna in the Japan Sea suggested decreased inflow of Pacific Central Water (PCW) species <em>Tricolocapsa papillosa,</em> increased subarctic species <em>Cycladophora sphaeris</em> and extinction of a dominant endemic radiolarian <em>Cycladophora nakasekoi</em>. These radiolarian fluxes showed ∼100-kyr eccentricity signals; however, the dominant paleoclimatic/paleoceanographic signal during the LMGC appeared to be ∼40-kyr obliquity cycle, which was not detected in the radiolarian fluxes possibly due to lower sampling resolution. Thus, orbital-scale variations of these radiolarian fluxes and their potential forcing mechanisms remain unclear.</div><div>In this study, we establish changes in the abundance of selected radiolarian species with a resolution that exceeds the 10-kyrs and suggest obliquity-paced changes in the paleoceanography in the Japan Sea during the LMGC. We detected ∼40-kyr cycles in abundance of <em>T</em><em>.</em> <em>papillosa</em>, suggesting that PCW inflow into the Japan Sea was controlled by a 40-kyr obliquity-paced glacial cycle. We also detected a ∼ 40-kyr signal in <em>C</em><em>.</em> <em>sphaeris</em> abundance, implying that the obliquity-paced winter monsoon probably promoted the inflow of subarctic water into the Japan Sea. Contrary, variation in <em>C</em><em>.</em> <em>nakasekoi</em> abundance lacks a ∼ 40-kyr signal. A 100-kyr cycle is also observed in a summer monsoon proxy from lacustrine sediment in China. Hence, it is possible that <em>C</em><em>.</em> <em>nakasekoi</em> decreased with weakened summer monsoon across the LMGC.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102448"},"PeriodicalIF":1.5,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148817","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}
引用次数: 0
The biostratigraphy and palaeobiogeography of the Late Jurassic dinoflagellate cysts from the Binalud Mountains, NE Iran 伊朗东北部比纳鲁德山脉晚侏罗世甲藻囊的生物地层学和古生物地理
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-27 DOI: 10.1016/j.marmicro.2025.102446
Behnaz Kalanat , Elham Davtalab , Ahmad Raoufian
{"title":"The biostratigraphy and palaeobiogeography of the Late Jurassic dinoflagellate cysts from the Binalud Mountains, NE Iran","authors":"Behnaz Kalanat ,&nbsp;Elham Davtalab ,&nbsp;Ahmad Raoufian","doi":"10.1016/j.marmicro.2025.102446","DOIUrl":"10.1016/j.marmicro.2025.102446","url":null,"abstract":"<div><div>This study investigates the dinoflagellate cysts from the upper part of the Dalichai Formation in the Binalud Mountains (NE Iran, western Tethys), where the deposits are primarily consist of shale and marlstone layers. The analyzed section yielded common and diverse dinoflagellate cyst assemblages comprising 46 species belonging to 33 genera. These assemblages are correlated with the DSJ24–DSJ33 dinoflagellate cyst Zones of the Late Jurassic (late Oxfordian–Tithonian) in the Northern Hemisphere. Key bioevents identified in this interval included the last occurrences of <em>Compositosphaeridium polonicum</em> in the late Oxfordian, the last occurrence of <em>Ctenidodinium ornatum</em> at the Oxfordian–Kimmeridgian boundary, the last occurrences of <em>Tubotuberella eisenackii</em> and <em>Scriniodinium crystallinum</em> in the early Kimmeridgian, and the last occurrence <em>Endoscrinium luridum</em> around the Kimmeridgian–Tithonian boundary. The dinoflagellate cyst assemblages exhibit strong similarities to the flora of the western Tethys (the Middle East, Europe, eastern North America, and North Africa) and are marked differences from coeval assemblages of the eastern Tethys (Australasia, eastern Asia, and northeastern India), reflecting significant provincialism between the western and eastern Tethys during the Late Jurassic.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102446"},"PeriodicalIF":1.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098473","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}
引用次数: 0
Variations in the morphometric characteristics of Fragilariopsis kerguelensis in the Southwest Pacific sector of the Southern Ocean over the past 40,000 years 过去4万年南大洋西南太平洋地区kerguelensis形态特征的变化
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-27 DOI: 10.1016/j.marmicro.2025.102447
Xavier Crosta, Thibault Sutre
{"title":"Variations in the morphometric characteristics of Fragilariopsis kerguelensis in the Southwest Pacific sector of the Southern Ocean over the past 40,000 years","authors":"Xavier Crosta,&nbsp;Thibault Sutre","doi":"10.1016/j.marmicro.2025.102447","DOIUrl":"10.1016/j.marmicro.2025.102447","url":null,"abstract":"<div><div>High-throughput measurements demonstrated the presence of two morphotypes of <em>Fragilariopsis kerguelensis</em> in the Atlantic sector of the Southern Ocean, the proportions of which in downcore samples may be used to reconstruct past sea-surface temperatures quantitatively. We here measured the mean length, width, area, and rectangularity in core SO136–111 to assess variations in both morphotypes in the Polar Front Zone of the western Pacific sector of the Southern Ocean over the past 40,000 years. Mean length, width, and area increased rapidly at the end of the glacial period when the Polar Front migrated southward to reach the core site, ocean temperature increased, and sea ice was no longer present. In contrast, mean rectangularity decreased at the end of the glacial period, when the proportion of the cold-water, high-rectangularity morphotype declined as the ocean warmed at the core site. Downcore patterns and quantitative values of all morphometric characteristics in the southwest Pacific sector agree well with previous studies from the Atlantic sector, suggesting the presence of a similar population of <em>F. kerguelensis</em> in the open Southern Ocean. Nevertheless, rectangularity-based relationships can ultimately produce unrealistic estimates of sea-surface temperatures in core SO136–111 when the proportion of the high-rectangularity morphotype is too low, indicating that these approaches are now limited to temperatures below 3–4 °C.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102447"},"PeriodicalIF":1.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098474","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}
引用次数: 0
Distribution of Miocene dinoflagellate cysts in the paralic basins of Tunisia: Paleogeographic and paleoecological reconstruction and eustatic movements 突尼斯海陆盆地中新世鞭毛藻囊的分布:古地理古生态重建与涨落运动
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-19 DOI: 10.1016/j.marmicro.2025.102443
Nadia Ben Moktar , Amel Mahjoubi-Ghanmi , Beya Mannai-Tayech
{"title":"Distribution of Miocene dinoflagellate cysts in the paralic basins of Tunisia: Paleogeographic and paleoecological reconstruction and eustatic movements","authors":"Nadia Ben Moktar ,&nbsp;Amel Mahjoubi-Ghanmi ,&nbsp;Beya Mannai-Tayech","doi":"10.1016/j.marmicro.2025.102443","DOIUrl":"10.1016/j.marmicro.2025.102443","url":null,"abstract":"<div><div>The Miocene deposits of northeastern and central-eastern Tunisia are primarily of clastic, deltaic-type. These deposits are organized into complex sedimentary sequences shaped by tectonic activity, eustatic fluctuations, and changes in climatic conditions. This study presents the evolution of dinoflagellate cysts associations extracted from Miocene-age deposits. These deposits ranged from 16 million to 5.3 million years ago. They are taken from three boreholes and three sections in northeastern and central Tunisia. Dinocysts serve as valuable indicators of climatic variations and sea-level fluctuations. Their study supports the results obtained from the analysis of pollen grains. It sheds light on paleoecology, paleogeography, and eustatic conditions during that period.</div><div>Various associations (oceanic, neritic, climatic, etc.) were established based on the ecological preferences of these marine microorganisms. Oceanic conditions are characterized by the presence of <em>Impagidinium</em>. Shallow marine environments are defined by the presence of <em>Cordosphaeridium inodes minimus</em>. Meanwhile, <em>Nematosphaeropis</em> and <em>Tectatodinium</em> indicate a neritic to oceanic environment. It is confirmed by the abundance of <em>Lejeunecysta</em>, <em>Operculodinium</em>, <em>israelianum</em>, <em>Polysphardium zoharyi</em>, <em>Homotryblium</em>, <em>Spiniferites</em>, <em>Cleistosphaeridium</em>, and <em>Lingulodinium machaerophorum</em>. These results align with lithological and biostratigraphic data related to paleobathymetry and paleogeography.</div><div>Changes in dinocyst taxa relative abundances helped track the shoreline's evolution during the Miocene. Variations in the relative abundance of <em>Impagidinium</em> and <em>Cordosphaeridium inodes minimus</em>, or their absence, indicate environmental shifts. This shift reflects a transition from a neritic environment (Aïn Grab Formation) to an oceanic one (Mahmoud Formation). The Saouaf Formation is marked by a eustatic drop at its base (Unit I). However, Units II and III are defined by eustatic rises in pulsations. The Somaa sands were deposited in a neritic and/or epicontinental environment, followed by a return to an oceanic setting (Melquart Formation).</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102443"},"PeriodicalIF":1.5,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098429","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}
引用次数: 0
Machine Learning for identification and classification of Foraminifera: Testing on monothalamids 有孔虫识别和分类的机器学习:单丘脑类的测试
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-18 DOI: 10.1016/j.marmicro.2025.102442
Anna Sabbatini , Francesca Caridi , Domenico Potena , Alessandra Negri
{"title":"Machine Learning for identification and classification of Foraminifera: Testing on monothalamids","authors":"Anna Sabbatini ,&nbsp;Francesca Caridi ,&nbsp;Domenico Potena ,&nbsp;Alessandra Negri","doi":"10.1016/j.marmicro.2025.102442","DOIUrl":"10.1016/j.marmicro.2025.102442","url":null,"abstract":"<div><div>Here we propose an AI-based approach using machine learning (ML) to assist species identification and reduce morphotype redundancy in the study of monothalamous foraminifera. In fact, this group of protists, is often overlooked in taxonomic studies due to their morphological simplicity and diversity. These single-celled organisms with “soft” tests are poorly studied, with only a few species identified, while many morphotypes remain undescribed. Taxonomic research on monothalamids is limited by challenges in identification, lack of fossilization, and the time-intensive nature of the work. This gap may lead to underestimating biodiversity and hinder detecting ecosystem degradation. Despite these challenges, monothalamids play key roles in marine ecosystems, making their diversity crucial for conservation and resource management. With this in mind, we analyzed images from the scientific literature, extracting key morphological traits, such as chamber shape, shell type, composition, and aperture type, through objective human annotation to build a dataset processed by ML algorithms. Clustering techniques, such as K-Means, revealed that basic shape, followed by shell type and composition, were the primary features distinguishing clusters. This approach enabled more objective morphotype classification, improving consistency and reducing human bias.</div><div>These findings align with recent taxonomic revisions and demonstrate that applying unsupervised ML methods enhances species identification accuracy and streamlines the analysis of high-dimensional datasets.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102442"},"PeriodicalIF":1.5,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098472","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}
引用次数: 0
Morphometric analysis of coccolithophore genus Reticulofenestra: Insights into taxonomy and evolution during late Eocene to early Oligocene 网状球石藻属的形态测量学分析:始新世晚期至渐新世早期的分类与演化
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-10 DOI: 10.1016/j.marmicro.2024.102435
Ruigang Ma , David Bord , Xiaobo Jin , Chuanlian Liu
{"title":"Morphometric analysis of coccolithophore genus Reticulofenestra: Insights into taxonomy and evolution during late Eocene to early Oligocene","authors":"Ruigang Ma ,&nbsp;David Bord ,&nbsp;Xiaobo Jin ,&nbsp;Chuanlian Liu","doi":"10.1016/j.marmicro.2024.102435","DOIUrl":"10.1016/j.marmicro.2024.102435","url":null,"abstract":"<div><div>The coccolithophore <em>Reticulofenestra</em> is key to understanding late Cenozoic climate change, but taxonomic identification remains challenging. This study uses morphometric and mixture analysis to evaluate taxonomic criteria for late Eocene to early Oligocene <em>Reticulofenestra</em>. The method enables a systematic comparison between the taxonomic morphotypes and the components recognized through Gaussian mixture modeling of parameters of distal shield length, circularity, and central opening ratio. At the species level, a total of nine morphotypes were studied from 6700 data points collected across three study sites in the mid–low latitude Atlantic–Indian Oceans. The results demonstrate that length and circularity effectively distinguish groups, validating their uses as primary taxonomic criteria. Nevertheless, central opening ratio exhibits high intra–group variability, limiting its standalone application. In addition, our integrated data reveal three evolutionary phases: (1) initial diversification during late Eocene cooling; (2) extinction following peak diversity after the Eocene–Oligocene Transition; and (3) early Oligocene stabilization reflecting adaptation in smaller species. This work provides statistical references for the validation of semi-quantitative morphologic descriptions, which may help establish a robust framework for identifying this ecologically vital lineage and enhance our understanding of phytoplankton responses to past environmental changes. Future genomic studies will be crucial for elucidating genotype-phenotype-environment relationships in <em>Reticulofenestra</em> evolution.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"195 ","pages":"Article 102435"},"PeriodicalIF":1.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098471","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}
引用次数: 0
High-resolution Danian–Selandian benthic foraminifera-based paleoenvironmental reconstruction and response to sequence stratigraphy: Inferences from the Elles section, El Kef Basin, Tunisia 突尼斯El Kef盆地Elles剖面的高分辨率Danian-Selandian底栖有孔虫古环境重建及层序地层学响应
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-01 DOI: 10.1016/j.marmicro.2024.102433
Sherif Farouk , Islam El-Sheikh , Sreepat Jain , Fayez Ahmad , Zaineb Elamri , Jenö Nagy , Khaled Al-Kahtany , Youssef S. Bazeen
{"title":"High-resolution Danian–Selandian benthic foraminifera-based paleoenvironmental reconstruction and response to sequence stratigraphy: Inferences from the Elles section, El Kef Basin, Tunisia","authors":"Sherif Farouk ,&nbsp;Islam El-Sheikh ,&nbsp;Sreepat Jain ,&nbsp;Fayez Ahmad ,&nbsp;Zaineb Elamri ,&nbsp;Jenö Nagy ,&nbsp;Khaled Al-Kahtany ,&nbsp;Youssef S. Bazeen","doi":"10.1016/j.marmicro.2024.102433","DOIUrl":"10.1016/j.marmicro.2024.102433","url":null,"abstract":"<div><div>High-resolution (123 samples) benthic foraminiferal distribution patterns were analyzed for paleoenvironmental reconstruction from a section located at the southern edge of the El Kef Basin (El Haria Formation; Tunisia) spanning the Danian–Selandian interval (planktic foraminifera P1a–P4b zones). Five distinct clusters were identified, each representing different paleoenvironments and depths ranging from inner neritic to upper bathyal, with significant variations in species diversity, paleoproductivity, and bottom water oxygenation. The Dan-C2 hypothermal event is characterized by moderately oxygenated bottom waters, high species diversity, and lowered paleoproductivity within an upper bathyal setting. The LDE is marked by high species diversity, higher paleoproductivity, moderately oxygenated bottom waters, abundance of epifaunal species, and shallowing to middle neritic depths. The Danian-Selandian boundary records (a) a sudden abundance of the inner neritic infaunal species <em>Bulimina strobila</em>, (b) an increase in species diversity, (c) moderately‑oxygenated bottom waters, (d) a positive δ<sup>13</sup>C excursion, and (e) deepening, from inner to middle neritic settings. Four transgressive-regressive (T-R) cycles based on benthic foraminiferal assemblage-derived bathymetry, P% and the transfer function-based estimate mirror each other, and distinctly mirror paleodepth changes, correlating with global eustatic cycles but also reflecting local tectonic influences.</div></div>","PeriodicalId":49881,"journal":{"name":"Marine Micropaleontology","volume":"194 ","pages":"Article 102433"},"PeriodicalIF":1.5,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095809","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}
引用次数: 0
Non-pollen palynomorphs as indicators of local environmental conditions in a Neotropical Estuary (Northeast Brazil) 巴西东北部新热带河口非花粉型孢粉形态对当地环境条件的指示作用
IF 1.5 4区 地球科学
Marine Micropaleontology Pub Date : 2025-01-01 DOI: 10.1016/j.marmicro.2024.102424
Pietro Martins Barbosa Noga , Anne de Vernal , Daniela Mariano Lopes da Silva , Doriedson Ferreira Gomes
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