Evolving Earth最新文献

{"title":"Comparative assessment of seasonal dynamics in water characteristics of Salim Ali Lake and Harsul Lake in Chhatrapati Sambhajinagar, Maharashtra, India","authors":"Prasanna Lavhale,&nbsp;Pranaya Diwate,&nbsp;Praful Shinde","doi":"10.1016/j.eve.2025.100101","DOIUrl":"10.1016/j.eve.2025.100101","url":null,"abstract":"<div><div>Lakes are inland water bodies serving as a freshwater resource. They are critical resources that sustain ecological balance and support human beings. Present study was carried out to assess the level of contamination of two lakes situated in the Chhatrapati Sambhajinagar city. Water samples from the Salim Ali Lake and the Harsul Lake were collected in the year 2024 across four seasons. Physicochemical and heavy metal analysis were carried out in the laboratory using rapid water testing kit to find out the level of contamination. Water Quality Index (WQI), Coefficient of Variation (CV), Nemerow Pollution Index (NPI) and Pearson Correlation were derived. An evaluation of NPI revealed that, during Winter season the Harsul Lake has NPI value 0.99 indicating substantial pollution while the Salim Ali Lake has NPI value 1.17 exhibiting heavy pollution. During Premonsoon season, observed NPI values of the Salim Ali Lake and the Harsul Lake were 1.07 and 0.83 respectively suggesting heavy pollution and moderate level of pollution respectively. In the Monsoon season, observed NPI values were 1.38 and 1.14 of the Salim Ali Lake and the Harsul Lake respectively which clearly depicted the higher level of pollution. The NPI value during Postmonsoon season slightly increases of both the lakes. The observed NPI value of the Salim Ali Lake and the Harsul Lake was 1.39 and 1.12 respectively indicating both lakes are heavily polluted. Overall analysis revealed that, the Salim Ali Lake is more polluted than the Harsul Lake. It might be due to the Salim Ali Lake is situated in central part of city while the Harsul Lake is situated at outskirt of the city. The spatial analysis carried out and Watershed delineation and land use land cover map were prepared using ArcGIS 10.8 software. Shuttle Radar Topography Mission – Digital Elevation Model data were utilized for preparing the watershed delineation map and Sentinel – 2 satellite imagery were used for the land use land cover classification of watershed. The present study helps policymakers to understand the current state of lake, allowing them to develop new policies accordingly. The water quality index emphasizes the urgent need of implementing pollution controlling strategies to stop further disintegration of the both the lakes.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145760840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress analysis of rocks using minor structures from two transects in the southern part of the belt of schuppen of Northeast India and its relationship with the orogenesis of the Indo-Myanmar ranges","authors":"Keneisazo Nagi,&nbsp;Chabungbam Mangi Khuman,&nbsp;Thejavinuo Mere,&nbsp;Soibam Ibotombi,&nbsp;Khundrakpam Kumarjit Singh,&nbsp;Arenlong Aier,&nbsp;Joyraj Singh Thounaojam","doi":"10.1016/j.eve.2026.100162","DOIUrl":"10.1016/j.eve.2026.100162","url":null,"abstract":"<div><div>Analyses of joint, conjugate fracture and slickenside data could reveal the stress fields responsible for the generation of NE-SW trending southern part of the Belt of Schuppen of Northeast India. Accordingly, rose diagrams and cyclographic plots of joints in relation to those of beddings, and orientations of principal stresses (σ₁, σ₂ and σ₃) from pi and contour diagrams of conjugate fracture and slickenside data are analysed. Most of the joints are principally of Mode I and Mode II types. The orientation of σ_1, determined from analyses of joints, conjugate fractures and slickensides, ranges from ESE to SE. The positions of the three principal stresses - σ₁, σ₂ and σ₃ determined from conjugate fracture analysis indicate that fracture systems of the belt are mainly produced by strike-slip faulting mechanism. The analysis of slickenside data indicates that most of the fractures are principally controlled by thrust faulting mechanism, even if normal and strike-slip faulting mechanisms are also observed. The frequent interchange of σ_1, σ₂ and σ₃ positions in pi diagrams of both conjugate fractures and slickensides implies a condition where the stress field has initially been controlled by thrust faulting mechanism followed by a strike-slip regime. This triggered the later phases of transpression related thrusting and normal faulting. The generation of the southern part of the Belt of Schuppen is attributed to a transpressional field that could have been driven by dextral shearing of the Dauki fault when it merged with the Naga thrust in the west and the Disang thrust in the east.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100162"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148843007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stratospheric cooling and accountable carbon dioxide removal","authors":"Behrouz Gholamahmadi","doi":"10.1016/j.eve.2026.100173","DOIUrl":"10.1016/j.eve.2026.100173","url":null,"abstract":"<div><div>The vertical temperature structure of the atmosphere provides a clear physical fingerprint of anthropogenic greenhouse-gas forcing: the troposphere is warming while the stratosphere is cooling. Recent satellite-based fingerprinting shows that the mid-to-upper stratosphere, approximately 25–50 km above Earth, cooled by about 1–2 °C from 1986 to 2022. This Short Communication uses this vertical fingerprint as an atmospheric entry point to the broader Earth-system challenge of accountable carbon storage. Sedimentary, paleoclimatic and biogeochemical records show that carbon reservoirs differ fundamentally in capacity, persistence, reversibility and feedback across timescales from years to millennia and beyond. These constraints motivate a conceptual atmosphere-to-reservoir framework for comparing carbon dioxide removal (CDR) pathways through five common accounting questions: the counterfactual, additional atmospheric CO₂ removal, full-chain emissions and leakage or displacement, storage location and persistence over a stated accounting horizon, and measurement variability and Earth-system feedbacks. Applied consistently, the framework distinguishes gross carbon transfer or measured stock change from verifiable net atmospheric removal across land-based, ocean-based and engineered CDR pathways. Stratospheric cooling is therefore not a project-level CDR metric, but a physical reminder that accountable CDR ultimately requires demonstrable atmospheric CO₂ removal and sufficiently durable storage.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100173"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149140701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbiome dynamics following coral transplantation and nursery culture in the Brazilian reef builder Mussismilia harttii","authors":"Tooba Varasteh ,&nbsp;Reza Amir Ahmadi ,&nbsp;Michele S. Lima ,&nbsp;Georgia C. Atella ,&nbsp;Claudia Omachi ,&nbsp;Ana Carolina Vicente ,&nbsp;Camila S. Oliveira ,&nbsp;Carlos D. Pérez ,&nbsp;Cristiane C. Thompson ,&nbsp;Paula B. Gomes ,&nbsp;Fabiano L. Thompson","doi":"10.1016/j.eve.2026.100106","DOIUrl":"10.1016/j.eve.2026.100106","url":null,"abstract":"<div><div>Coral reefs, vital ecosystems that support diverse marine life, are increasingly facing threats from anthropogenic activities and environmental changes. In this study, we analyzed the site-specific effects of coral translocation on coral holobiont microbiomes. Polyps of <em>Mussismilia harttii</em> were transplanted from one reef location (Japaratinga, Alagoas, Brazil; JP) to another (Porto de Galinhas, Pernambuco; PG) 95.6 km away. JP is characterized by higher coral abundance and larger colony size indices than PG. Because the study design includes only two geographically distinct sites, interpretations are restricted to these locations. This study tested the hypothesis that donor-reef origin influences site- and time-associated longitudinal microbiome trajectories. The microbiome of transplanted JP corals differed after 1 month at PG, consistent with short-term compositional adjustment to local conditions rather than an inference of physiological stress; alpha-diversity differences were also detected and are reported descriptively without attributing environmental causation. After this period, transplanted corals demonstrated an increase in putative symbiont-associated genera (e.g., <em>Ruegeria</em>, <em>Labrenzia</em>, and <em>Paracoccus</em>) according to 16S rRNA amplicon analysis with multiple-comparison control (q &lt; 0.05). The PG seawater showed an enrichment of taxa commonly associated with nutrient-enriched or impacted coastal waters (e.g., <em>Nitrospira, Desulfovibrio, Escherichia</em>, and <em>Arcobacter</em>), providing environmental context for the distinct coral-associated microbiome patterns observed at this site. At 15 months, microbiomes of transplanted JP corals were more similar to JP controls than to PG controls. These results suggest a partial, site-specific donor-origin microbiome signature and support incorporating longitudinal microbiome monitoring into translocation assessments for restoration.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100106"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standalone and novel hybrid ML models for estimating stream velocities in a river channel with vegetation","authors":"Sanjit Kumar ,&nbsp;Mayank Agarwal ,&nbsp;Upaka Rathnayake","doi":"10.1016/j.eve.2026.100115","DOIUrl":"10.1016/j.eve.2026.100115","url":null,"abstract":"<div><div>Vegetation present in the flowing water bodies offers a substantial amount of obstruction to the flow. By influencing the flow velocities, these vegetative elements may alter the hydrodynamic characteristics of a river channel. Several laborites as well as field studies have been carried out for a better estimation of vegetation influenced stream velocities. This study investigates the applicability of artificial intelligence-based approaches for the estimation of velocities in a river channel, where the presence of vegetative elements influences a stream's flow characteristics. To estimate the flow velocities, we made use of a Reduced Error Pruning Tree (REPT), Random Forest (RF), and Random Tree (RT) models as standalone models and used them with hybrid ML models like Multi Scheme (MS) and Random Committee (RC) models. In all, we explored nine ML models, viz., REPT, MS-REPT, RC-REPT, RF, MS-RF, RC-RF, RT, MS-RT, and RC-RT. Performance of the applied approaches has been evaluated by using several performance metrics (Pearson Correlation Coefficient (<em>R</em>), Nash-Sutcliffe Efficiency (<em>NSE</em>), Agreement Index (<em>AI</em>), Root Mean Squared Error (<em>RMSE</em>), Scatter Index (<em>SI</em>), Percent bias (<em>PBias</em>), and Kling-Gupta efficiency (<em>KGE</em>)). Hybrid ML models outperform their standalone variants as well as the empirical equations. Out of these models, MS-RF (<em>R=0.957, NSE=0.915, AI=0.977, SI =0.240, PBias=1.597, RMSE=0.072, and KGE=0.928</em>) outperformed other approaches in terms of accuracy, followed by RC-RF, RF, RC-RT, MS-RT, RT, RC-REPT, REPT, and MS-REPT.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100115"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147397057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Danian paleotemperature records from Neuquén Basin-Argentina: Applications of the ostracod Sr/Ca paleothermometer","authors":"Marlone H.H. Bom ,&nbsp;Karlos G.D. Kochhann ,&nbsp;Rodrigo do Monte Guerra ,&nbsp;Daiane Ceolin ,&nbsp;Guilherme Krahl ,&nbsp;Luciana R.C. Duarte ,&nbsp;Mírian L.A.F. Pacheco ,&nbsp;Thorsten Bauersachs ,&nbsp;Luiz Frederico Rodrigues ,&nbsp;Flavia Callefo ,&nbsp;Franciele Agnesa Trentin ,&nbsp;Douglas Galante ,&nbsp;Telma Musso ,&nbsp;Lorenz Schwark ,&nbsp;Andrea Concheyro ,&nbsp;Gerson Fauth","doi":"10.1016/j.eve.2026.100113","DOIUrl":"10.1016/j.eve.2026.100113","url":null,"abstract":"<div><div>The early Danian is marked by a recovery in marine and terrestrial ecosystems after the Cretaceous-Paleogene mass extinction. Both sea surface temperature (SST) and bottom water temperature (BWT) reconstructions are essential for a better understanding of paleoclimatic developments occurring at this critical time interval. Paleotemperature reconstructions based on ostracods are an excellent alternative for studies in regions where benthic foraminifera are scarce or absent. In this context, we present a paleotemperature reconstruction of the Cerro Azul Section, Neuquén Basin, Argentina, based on the ostracod <em>Henryhowella</em> (Wichmannella) <em>meridionalis</em> (Bertels, 1974). Trace element/calcium ratios (El/Ca) were determined on well preserved specimens using two different analytical techniques: (i) oxidative cleaning followed by acid digestion (measured with ICP OES), and (ii) laser ablation (measured with LA-ICP-MS). Our results show that El/Ca ratios of ornamented species are more effectively quantified using acid digestion. Although some intervals show high values of the Al/Ca ratio, which could suggest the presence of remaining clay and/or organic contaminants. Low values of both Fe/Ca and Mn/Ca ratios indicate efficient cleaning regarding oxyhydroxides. As the incorporation of Mg and Sr into inorganic calcite is a thermodynamic process, we mapped the distribution of both trace elements on ostracod valves in nanoscale using Synchrotron-based X-ray fluorescence (nannoXRF). Our results show that Sr/Ca has a negligible correlation with Al/Ca, and Sr appears to be more homogeneously distributed compared to Mg in <em>Henryhowella</em> (Wichmannella) <em>meridionalis</em> valves. Therefore, we opted to apply the Sr/Ca ratio as a paleothermometer in the studied Danian ostracods, consisting in the first ostracod-based BWT record for the Paleogene. Our results indicate stable BWT values throughout the studied interval at the Cerro Azul Section, ranging between 5.1 and 8.8 °C (oxidative cleaning), and 7 to 13 °C (laser ablation). BWTs show the expected offset (colder temperatures) to TEX^H₈₆ and stable oxygen isotope (δ¹⁸O)-derived SSTs, which ranged from 28.3 to 31.8 °C, with TEX^H₈₆ depicting a 2.5 °C warming between calcareous nannofossil zones AP0 and AP1a. The present study demonstrates the potential of using the elemental composition of ostracod valves as a new tool for reconstructing past deep ocean temperature variations.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100113"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolving thermodynamic convective environments over India: spatio-temporal variability, trends, and regime shifts","authors":"Modugu Aruna ,&nbsp;Kandula Bharghavi ,&nbsp;Thotli Lokeswara Reddy ,&nbsp;Krishnareddigari Krishna Reddy","doi":"10.1016/j.eve.2026.100132","DOIUrl":"10.1016/j.eve.2026.100132","url":null,"abstract":"<div><div>Convective environments over India are experiencing significant spatio-temporal evolution under the combined influence of monsoon dynamics, thermodynamic variability, and ongoing climate warming. Understanding how atmospheric instability, convective inhibition, and moisture–temperature coupling vary across regions, seasons, and decades is essential for assessing changes in thunderstorm activity and extreme rainfall risk. This study presents a comprehensive assessment of thermodynamic convective environments over India during 1981–2020 using ERA5 reanalysis data. Key instability diagnostics Convective Available Potential Energy (CAPE), Convective Inhibition (CIN), K Index (KI), Total Totals Index (TTI), and Net Convective Potential (NCP) are analyzed to characterise climatological patterns, seasonal and interannual variability, long-term trends, relative variability, and regime shifts. Results reveal strong spatial heterogeneity in convective environments, with eastern, northeastern, and peninsular India consistently exhibiting higher instability due to persistent moisture transport and monsoon forcing, while western and northwestern regions remain comparatively inhibited. Seasonal analysis highlights a pronounced monsoon control, with pre-monsoon and monsoon periods displaying the most favorable thermodynamic conditions for deep convection. Trend and decadal analyses indicate widespread increases in moisture-driven instability, reflected by rising CAPE and KI and weak or declining CIN across large parts of India, whereas lapse-rate-driven instability (TTI) shows comparatively weak or negative trends. Relative variability analysis demonstrates that CAPE and KI exhibit high interannual variability over arid and semi-arid regions, indicating greater sensitivity to moisture fluctuations and boundary-layer processes. Spatial change-point detection reveals pronounced non-stationarity in convective environments, with coherent regime shifts occurring predominantly during the late 1990s and early 2000s, particularly during pre-monsoon and monsoon seasons. These findings indicate that convective environments over India are evolving through a combination of gradual thermodynamic amplification and abrupt regime shifts. Overall, the results suggest that increasing thunderstorm and extreme rainfall risk over India is primarily driven by moisture-related thermodynamic enhancement modulated by monsoon dynamics, rather than uniform large-scale destabilisation, with important implications for convective predictability and climate adaptation in a warming monsoon system.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100132"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147858481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating remote sensing and GIS-based AHP for flood hazard assessment in the Damodar River Basin, India","authors":"Mukesh Khadav,&nbsp;Aditya Sharma,&nbsp;Devesh Sharma,&nbsp;S.K. Panda","doi":"10.1016/j.eve.2026.100123","DOIUrl":"10.1016/j.eve.2026.100123","url":null,"abstract":"<div><div>Flooding is one of the most catastrophic natural hazards in India, causing significant socio-economic losses annually. Despite the widespread application of GIS-based Analytical Hierarchy Process (AHP) methods for flood hazard assessment, limitations remain in capturing fine-scale hydrological variability. Addressing this gap, the present study advances existing frameworks by integrating additional hydrological indicators specifically the Normalized Difference Water Index (NDWI) and surface roughness to enhance the spatial precision of flood hazard mapping in the Damodar River Basin. This study employs a GIS-based Analytic Hierarchy Process (AHP) within a multi-criteria decision-making (MCDM) framework to delineate flood hazard zones in the Damodar River Basin by assigning relative weights to key influencing factors. Parameters such as elevation, slope, roughness, land-cover, drainage density, topographic wetness index (TWI), (NDWI), annual rainfall, and proximity to rivers were analyzed to evaluate the spatial distribution of flood hazard regions. Thematic maps of these parameters were derived using remote sensing data, including SRTM Digital Elevation Model (DEM) and other scientific datasets. The primary purpose of this study is to develop a robust GIS–AHP framework for flood hazard assessment in the Damodar River Basin, providing scientific evidence to guide targeted mitigation and policy interventions. Weighted values for factors were computed, with elevation (0.2099), slope (0.1894), and rainfall (0.1459) being the most critical contributors, while roughness (0.0265) had the least impact. The calculated consistency ratio (CR) of 0.0562, well below the threshold of 0.1, validates the robustness of the weight assignments. The results reveal that approximately 2.42% (1015 km²) of the basin is categorized as low hazard level, 31.01% (12,997 km²) as moderate hazard level, 56.25% (23,571 km²) as high hazard level, and 10.32% (4326 km²) as very high hazard level. This analysis provides a critical foundation for targeted flood mitigation strategies and resource allocation, emphasizing the need to address high and very high hazard zones to minimize future flood impacts effectively.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100123"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147709507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoenvironmental significance of saproxylic invertebrate coprolites preserved in Agathoxylon fossil wood from the Araripe Basin, Brazil","authors":"Amanda Santa Catharina ,&nbsp;Diego Luciano Nascimento ,&nbsp;Filipe Giovanini Varejão ,&nbsp;Mariza Gomes Rodrigues ,&nbsp;Marcello Guimarães Simões ,&nbsp;Mario Luis Assine","doi":"10.1016/j.eve.2026.100137","DOIUrl":"10.1016/j.eve.2026.100137","url":null,"abstract":"<div><div>Fossil woods hosting communities of colonizing organisms provide valuable paleoecological information, offering insights into plant–arthropod interactions, feeding strategies, and trophic organization in ancient ecosystems. Here we report the first record of coprolite-bearing fossil woods of the coniferous morphogenus <em>Agathoxylon</em> (with affinity to <em>Agathoxylon santanensis</em> Santos et al., 2021) from the Aptian–Albian Romualdo Formation, Araripe Basin, northeastern Brazil. The silicified wood preserves decay features and evidence of saproxylic activity, including coprolites attributed to wood-boring coleopterans, oribatid mites, and termites. Thin section analysis reveal decay features associated with fungal activity, indicating that colonization occurred only post-mortem. The occurrence of coleopteran, oribatid mite, and termite coprolites may represent a successive colonization by wood-feeding arthropods, driven by changing substrate conditions during wood decay. Although this interpretation is plausible the synchronicity of colonization remains uncertain. The presence of <em>Microcarpolithes hexagonalis</em> (Vangerow, 1954), a type of coprolite related commonly to drywood termites (Kalotermitidae or Mastotermitidae), indicates a later stage of decay, when the wood was already thoroughly dried, and their presence suggests prolonged low-moisture conditions within the substrate, in an arid to semi-arid environment. Although the global record of termite coprolites remains sparse, the specimens from the Araripe Basin provide robust evidence for the presence of dry-wood termites during the Aptian-Albian, in agreement with an increasing number of records from South America. Additionally, our findings, evidenced by borings containing coprolites of termites and oribatid mites, support the hypothesis that cohabitation in termite nests was already established during the Cretaceous.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100137"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147995713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Industrial suitability of upper cretaceous limestone in Mbalangi, Ediki, Kendonge and Mungo River, Mungo River Formation, Northwestern Douala basin, Cameroon (West Africa): A geochemical approach","authors":"Esue Fidelis Mokake ,&nbsp;Florence Njinto Kwankam ,&nbsp;Ligbwah Victor Wotanie ,&nbsp;Lemnyuy Prosper Yiika ,&nbsp;Christopher M. Agyingi","doi":"10.1016/j.eve.2026.100139","DOIUrl":"10.1016/j.eve.2026.100139","url":null,"abstract":"<div><div>The geochemistry of limestone deposits in the Mungo River Formation, Northwestern Douala Basin, Cameroon was studied through field geologic mapping and geochemical analysis to evaluate the suitability of limestone for the production of Portland cement and other industrial applications. Field studies reveal four types of limestone deposits: the Mbalangi series, the Kendonge River series, the Ediki River series, and the Mungo River series. The limestones are thinly to thickly bedded (5.0 to 15.6 m), highly indurated, and show crystalline structure with a very fine-grained texture and are associated with shales. Geochemical analyses of limestones from Mungo River Formation (MRF) indicate that the Mbalangi limestone series has the best grade, followed by limestones from the Mungo River series, and the Ediki limestone series. These limestones, according to the CaO/MgO and CaCO₃ scheme, are classified as pure limestones with medium to very high purity, which are all suitable for Portland cement production with less than 0.52 wt% MgO, less than 1.89 wt% FeO, less than 5 wt% total alkalis, and CaCO₃ ranging from 88.86 to 99.80 wt%. These deposits also qualify for use as flux in the steel industry for their high CaCO₃ content and less than 5 wt% SiO₂ content. In addition, the deposits also meet specifications for use in ceramics with &gt;79 wt% of CaCO₃. Furthermore, the Mbalangi limestone series (88.70 to 99.77 wt% of CaCO₃), the Ediki River limestone series (90.05 to 94.55 wt% of CaCO₃), and the Mungo River limestone series (97 to 99.89 wt% of CaCO₃) are suitable for glass manufacture, refractories, chemical production, sugar refining, textiles, agriculture, and soda ash manufacture. The Kendonge limestone series shows low grade with CaO (43.31 wt%), CaO/MgO (28.44), and MgO/CaO (0.04), suggesting magnesian limestone (limey marlstone), which is not suitable for Portland cement production. The negative correlation of calcium oxide with iron (III) oxide and magnesium oxide in these limestone deposits signifies an increase in the leaching of CaO solution in the environment, which, in turn, increases the purity of the limestone, making it suitable for the production of Portland cement.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"4 ","pages":"Article 100139"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147995611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}