Sediment Samples Research Articles

Linking the PETM and North Atlantic volcanism using tellurium in sediments

The Paleocene – Eocene Thermal Maximum (PETM) was a short period (~170 kyr) of global temperature rise starting at 55.93 Ma, which occurred during the breakup of the North Atlantic and the emplacement of the North Atlantic Igneous Province (NAIP). Recently, mercury (Hg) concentrations in sediments have been used in an attempt to connect the eruptive history of the NAIP with environmental change during this period, at a higher resolution than possible using geochronology. Here we present sedimentary tellurium (Te) as a novel proxy to further reconstruct NAIP volcanism at high resolution. We measured 45 trace elements in 401 sediment samples from 3 sections across the PETM in the northern hemisphere. All study sites exhibit an increase in Te concentrations and Te/Th ratios close to the onset of the PETM and remain high until the end of the main North Atlantic ash phase about 1 Myr later. The trace element data indicate that changes in sediment lithology or in environmental conditions do not influence sedimentary Te concentrations suggesting a volcanic source instead. We used existing age models to remove the effect of changes in sedimentation rate and calculated volcanic Te fluxes. Our Te data suggest increased volcanism in the latest Paleocene and early Eocene. This fits existing radiometric ages of the NAIP, which demonstrate that a more than 5 km thickness of lava in eastern Greenland and the Faroes was erupted within about 1 Myr between ~56 to ~55 Ma. All our study sites show similar Te flux variations across the PETM. In contrast, sedimentary mercury (Hg) profiles from these and other sites are less consistent. Tellurium in sediments may represent a useful proxy to reconstruct NAIP volcanism.

Anatomy of Niger and Benue river sediments from clay to granule: grain-size dependence and provenance budgets, Nigeria

ABSTRACT This study explores in detail the complexity of textural–compositional relationships in fluvial sediments. To this aim, fifteen size fractions (from clay to granule) of three sediment samples characterized by virtually identical size distribution from the Niger and Benue rivers in central Nigeria were separately analyzed by multiple methods (optical microscopy, manual and semi-automated Raman spectroscopy, X-ray diffraction, elemental geochemistry, Nd isotopes). The independent mineralogical and geochemical datasets thus obtained allowed us to investigate processes of sediment generation for five diverse size modes (clay, fine cohesive silt, very coarse frictional silt, very fine sand, coarse sand) derived in different proportions from different sources (wind-blown dust, soils and paleosols, fine-grained and coarse-grained siliciclastic units, igneous and metamorphic bedrocks). Controls on the size distribution of detrital minerals (settling equivalence, size inheritance, weathering, mechanical durability, and chemical durability through multiple sedimentary cycles) were examined, specifically focusing on tectosilicates and on the long-standing petrological problem of feldspar–grain-size relations. Various factors determine the composition of different size modes: kaolinite-dominated clay derives from both deeply weathered soils or paleosols and distant Saharan sources; cohesive silt is largely recycled from mudrocks and soils formed in sedimentary basins. The proportion of detritus derived first-cycle from basement rocks increases from very coarse silt to very fine sand, whereas the coarse-sand mode is quartz-dominated with scarce plagioclase and amphibole and local occurrence of garnet, staurolite, monazite, or xenotime reflecting a combined influence of size inheritance from igneous (pegmatite) and metamorphic sources, mechanical and chemical durability, and recycling from coarse-grained siliciclastic units. Sediment budgets based on mineralogical, geochemical, and geochronological signatures consistently indicate dominance of Benue sediment supply, although the contribution from the Niger mainstem to the Niger Delta is inferred to have been notably greater in the wetter past, before clastic fluxes dropped in response to the aridification of the Sahel.

Aquibaculum sediminis sp. nov., a halotolerant bacteria isolated from salt lake sediment.

An aerobic, Gram-stain negative bacterium was isolated from sediment samples of Barkol salt lake in Hami City, Xinjiang Uygur Autonomous Region, China, with the number EGI_FJ10229T. The strain is ellipse-shaped, oxidase-negative, catalase-positive, and has white, round, smooth, opaque colonies on marine 2216 E agar plate. Growth occurs at 4.0-37.0℃ (optimal:30.0℃), pH 7.0-9.0 (optimal: pH 8.0) and NaCl concentration of 0-8.0% (optimal: 3.0%). Phylogenetic analysis based on 16S rRNA gene and genome sequences indicated that the isolated strain should be assigned to the genus Aquibaculum and was most closely related to Aquibaculum arenosum CAU 1616T. Average nucleotide identity (ANI) and Average amino-acid identity (AAI) values between the type species of the genus Aquibaculum and other related type species were lower than the threshold values recommended for bacterial species. The genomic DNA G + C content of EGI_FJ10229T was 65.41%. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylcholine, phosphatidylethanolamine and unidentified phospholipid. The major fatty acids (> 5%) were C19:0 cyclo ω8c (42.0%) and C18:1 ω7c (33.78%). The respiratory quinone identified was Q-10. Differential phenotypic and genotypic characteristics of this strain and species of genus Aquibaculum showed that the strain should be classified as representing a new species belonging to this genus, for which the name Aquibaculum sediminis sp. nov. is proposed. The type strain of the proposed novel species is EGI_FJ10229T (= KCTC 8570T = GDMCC 1.4598T).

Occurrence and distribution of antibiotic resistance genes in Rivers entering the sea from the South bank of Laizhou Bay, China

The distribution of antibiotic resistance genes (ARGs) in Laizhou Bay affects the local socio-economic development. The study aimed to investigate the distribution of ARGs in the rivers that flow into the sea around Laizhou Bay’s southern shore. Water and sediment samples were collected from different typical sites of rivers entering the sea in Weifang, including Mi River, Bai Lang River, Yu River, Wei River, Jiaolai River, Xiaoqing River and Di River. The species and abundance of ARGs in the sediments were characterized and quantified by macro-genome high-throughput sequencing technology. The species distribution of ARGs was compared. In two sediment samples and seven water samples, 24 ARGs types and 1244 subtypes of ARGs were detected, in which multidrug-resistant class was the main ARGs type and FBJ murine osteosarcoma viral oncogene homolog B (fosB) was the dominant ARGs. The types of ARG in the top ten of these samples were the same, although the proportion was different. Dominant ARG subtypes accounted for more than 50% of all the nine samples. This article provides basic data support for pollution status and environmental risk assessment as well as remediation of ARGs in rivers entering the sea along the south coast of Laizhou Bay.

Composition of Bivalve Community in the Coastal Waters (0–4 m) of the Çanakkale Strait Along With Various Environmental Variables

The present study focused on the soft bottom of the coastal waters (0-4 m) in the Çanakkale Strait. The objective was to determine the composition of bivalve species in the area. Sediment samples were collected using a 30×30 cm quadrat system by a SCUBA diver at eight sites between July 2008 and April 2009. The study recorded a total of 2299 individuals belonging to 55 species. The most abundant species in the study area was Lucinoma borealis. A significant positive correlation was found between seawater salinity and species diversity (rs = 0.59; p

TOTAL NITROGEN CONTENT IN SEDIMENTS IN THE MANGROVE AND CRAB CONSERVATION AREA OF TARAKAN CITY

Nitrogen in sediments is an essential element for plants that play a role in the process of photosynthesis and stimulate growth. This study aims to examine the total Nitrogen (N) content in sediments based on differences in depth in the Mangrove and Crab Conservation Area of Pamusian Village, Tarakan City. The method used in the research is quantitative descriptive method by describing the content of Nitrogen (N) in sediments based on differences in depth at each research station and determining the location of sampling points for sampling using purposive sampling method. Sediment sampling was carried out at 3 station points, namely the Pamusian River flow area, the watchtower area and the area near residential areas. Sediment sample testing was carried out at the Soil Laboratory of the Faculty of Agriculture, Borneo University of Tarakan. The results of this study showed that the Nitrogen (N) content in sediments in the Mangrove and Crab Conservation Area of Pamusian Village at a depth of 10 cm ranged from 0.25 - 0.32%, a depth of 20 cm ranged from 0.19 - 0.24%, and a depth of 30 cm ranged from 0.14 - 0.20%. The highest total nitrogen content is at a depth of 10 cm and the station that has the highest total nitrogen content is station 3.

Study on Grain Size, Physical Properties and Organic Matter Characteristics of Tidal Flat Surface Sediments: May 2022 Hwangdo Tidal Flat Dataset, Cheonsu Bay

This study analyzes the geological and geochemical features of surface sediments in the Hwangdo Tidal Flat, located on Korea’s West Coast. The tidal flat experiences semi-diurnal tides, impacting organic matter decomposition and nutrient cycling. Ninety one sediment samples were collected and analyzed for physical and chemical properties including grain size, density, water content, organic carbon, and nitrogen. Sediments consist mainly of sand and silt, with coarser sediments near the main channel and finer sediments towards the west. Sediment grain size averages 4.12 Φ with a sorting coefficient of 1.96 Φ, indicating diverse energy environments. Total organic carbon and nitrogen correlate positively with grain size and density, reflecting sediment origin and environment. Kriging maps sediment grain size distribution, while correlation and linear regression analyses show relationships between variables. High correlations exist between various parameters, aligning with tidal flat characteristics and aiding understanding of sediment transport and deposition. The study provides baseline data for understanding the tidal flat’s geological, geochemical, and physical aspects, valuable for remote sensing validation and environmental monitoring. The dataset is freely available for research and management purposes.

Rapid Monitoring of Aquatic Organism Biodiversity Based on Environmental DNA in a Medium-Sized Reservoir

Environmental DNA (eDNA) has emerged as a highly sensitive and efficient tool for the biomonitoring of aquatic ecosystems. In this study, we investigated fish and benthic species communities using eDNA techniques in a medium-sized reservoir (about 3 square kilometers) in Anhui, China. A total of 12 water samples and 11 sediment samples were analyzed by 12S and 18S primers, respectively. We analyzed the composition of species diversity and the effect of seven environmental factors using the Mantel test. A total of 42 fish taxa were present in the water samples, and 188 benthic taxa in the sediment samples. Species composition was different in disparate stations. We found that water temperature and salinity are pivotal factors influencing the composition of fish communities, while chlorophyll-a is a primary environmental determinant for benthic species assembly structures across different zones. Biodiversity information generated by eDNA techniques can be used to reflect the resource status of this reservoir. The relevant results will provide important scientific reference information for the development and exploitation of medium-sized reservoirs.

Fungi of the Arctic Seas

The abundance and diversity of mycelial fungi in the bottom sediments of the Arctic Ocean seas (the Greenland, Barents and Kara seas) were studied. Samples of the surface bottom sediments were collected during the 84th (July‒August 2021) and 86th (October‒November 2021) cruises of RV Akademik Mstislav Keldysh. The taxonomic affiliation of the isolated fungi was determined using polyphasic taxonomy. The isolated fungi belonged to 16 genera of different classes of ascomycetous, basidiomycetous, and zygomycetous fungi. The effect of cultivation temperature and different NaCl concentrations on fungal growth was determined, as well as the effect of cultivation conditions on the fatty acid profile for the strains capable of growth on media with increased osmotic potential. While fatty acid composition was shown to be affected by changes in environmental conditions, the response to osmotic stress differed among the studied cultures from deep-sea sediments.

Filamentous Fungi in the Sediments of the East Siberian and Laptev Seas

This is the first report on abundance and diversity of cultured yeasts and filamentous fungi in the sediments of the Laptev and East Siberian seas. A total of 63 isolates of mycelial fungi belonging to 32 morphotypes were obtained from 35 sediment samples. Most morphotypes were represented by single colonies in individual samples; the most often occurring species were Pseudeurotium zonatum, Pseudogymnoascus pannorum, and Cordyceps farinosа. In both seas, abundance of filamentous fungi (up to 12 colonies per 1 g wet sediment) was lower than that of yeasts (up to 68 colonies per 1 g wet sediment). In the Laptev Sea, yeast abundance was low at all stations, while in the East Siberian Sea higher values were found at near-estuarine stations.

An Analysis Management by Mike 21 Modelling at Rolak 70 Retention Pool in Jombang Regency, East Java Province, Indonesia

Some areas in Indonesia have high level of sedimentation problems that able to cause flooding, and one apparent solution is to build a retention pool. Sedimentation is deposition of material into the reservoir or dam due to environmental damage or erosion occurs in the river basin area. Sedimentation becomes the main factor in constructing the Rolak 70 Retention Pool, as an important component in controlling floods on the Konto River when the water discharge exceeds the maximum limit. From geography perspective, the modelling location is in waters located between 112° 11′ 22.85″ South Latitude and 7° 38′ 42.23″ East Longitude. The model area has northern boundary at the tip of Rolak 70 pool, while western boundary at the outlet of Rolak 70 pool. The lowest water depth value is located in upstream area of Konto River at coordinates of 112°11’27.81″ South Latitude and 7°38’49.27″ East longitude. Weight of soil sample taken from the research site was ± 1000 grams at each point, and the result of sediment sample test performed at the Soil Mechanics Laboratory of Civil Engineering Department, Sultan Agung University, Semarang showed that the research area is dominated by sand, followed by mud and gravel. There were several tests conducted include grain size analysis, hydrometer analysis, and specific gravity analysis to determine the D50 of the sediment. In the study area, several sampling points were taken, started from upstream area of the river in front of Rolak 70 building to the Rolak 70 Retention Pool. For this purpose, a MIKE 21 software modelling was used to determine distribution and lines of sedimentation in the study area. As visible from changes found in bed level morphology that occurred in Rolak 70 Retention Pool by cross section extraction, it can be seen that the largest change occurred in analysis for line 1 and the smallest bed level changes occurred in the analysis for line 6. Then, the result revealed that sedimentation tends to occur at large locations in upstream area of Rolak 70 Retention Pool, while the smallest sedimentation potential will happen at the downstream area of Rolak 70 Retention Pool. These results can be caused by changes of speed from the river flow which tends to decrease towards the end of Rolak 70 Retention Pool. So, the river flow has no more energy to carry heavy amount of sediments originating from the upstream area of the Konto River. By the existence of this retention pool, the need for rice field irrigation will not be disturbed by sediment deposits. In addition, the Rolak 70 Retention Pool can be used as temporary storage for material from Mount Kelud eruption where these materials can be utilized as building material or other useful purposes.

O USO DE GEOTINTAS NA PINTURA – A EXPERIÊNCIA DO ATELIÊ TERRA & TELA

Historically, natural pigments have been central to artistic expression, from prehistoric cave paintings to techniques employed by ancient and medieval civilizations. Recently, there has been renewed interest in these materials for their unique aesthetic and eco-friendly qualities. This study investigates the use of geotints, natural pigments derived from soils and sediments, in contemporary art through the experience of Terra & Tela studio. The research focuses on the process of creating geotints from soil and sediments samples collected in Tocantins state, Brazil, a region known for its rich geodiversity. The research details the process of geotint production, from material collection to application on canvas, and discusses the artistic and environmental implications of this practice. The project integrated geotints into artistic practice through exhibitions and workshops that highlighted their unique textures and colors. Key findings show that geotints effectively merge scientific concepts with art. Workshops, where participants prepared and used these pigments, demonstrated the approach’s educational value. By linking art with science, geotints provided a hands-on understanding of soil properties and geological processes, enriching both artistic creativity and scientific literacy. This study emphasizes art’s role in bridging scientific knowledge with creative expression.

Mineral Signatures in Oued K’sob River (Algeria): Highlighting Geological Variations and Potential Anthropogenic Impacts

This study examines the mineral composition of sediment samples collected from five distinct zones along the Oued K’sob River in Bordj Bou Arreridj, Algeria using scanning electron microscopy (SEM). The analysis revealed intriguing patterns, the Zone 5 emerged as a distinct outlier, exhibiting significantly lower calcium (29.32% vs. 53.25% in Zone 1) and iron (14.94% vs. 6.31% in Zone 1) content compared to other zones, while displaying a higher silicon content (28.82% vs. 25.27% in Zone 1). This suggests a unique geological origin or specific weathering processes shaping the mineral fingerprint of Zone 5. Interestingly, Zones 1, 2, and 3 displayed a relative consistency in silicon content (around 25%, with pairwise comparisons exceeding p > 0.05), suggesting potential similarities in mineral sources or enrichment mechanisms within their watersheds. However, Zone 4 deviated slightly, showing a higher calcium content (64.18% vs. 29.32% in Zone 5) and lower silicon content (17.99% vs. 28.82% in Zone 5), indicating potential differences in its geological makeup or weathering processes. Furthermore, all zones exhibited trace amounts of elements like lead (Pb) and cadmium (Cd) (ranging from 0.76% to 2.16% for Pb and 0.000% to 0.114% for Cd) (Please recheck these values They are very high). This warrants further investigation to understand their potential anthropogenic origins and impact on the river ecosystem. Further investigations incorporating detailed geological surveys, isotopic analyses, and expanded sampling strategies are recommended to gain a more comprehensive understanding of the complex factors shaping the sediment chemistry within the Oued K’sob River system.

Natural Attenuation Potential of Vinyl Chloride and Butyl Acrylate Released in the East Palestine, Ohio Train Derailment Accident.

The East Palestine, Ohio train derailment released toxic vinyl chloride (VC) and butyl acrylate (BA), which entered the watershed. Streambed sediment, surface water, and private well water samples were collected 128 and 276 days postaccident to assess the natural attenuation potential of VC and BA by quantifying biodegradation biomarker genes and conducting microcosm treatability studies. qPCR detected the aerobic VC degradation biomarkers etnC in ∼40% and etnE in ∼27% of sediments collected in both sampling campaigns in abundances reaching 105 gene copies g-1. The 16S rRNA genes of organohalide-respiring Dehalococcoides and Dehalogenimonas were, respectively, detected in 50 and 64% of sediment samples collected 128 days postaccident and in 63 and 88% of sediment samples collected 276 days postaccident, in abundances reaching 107 cells g-1. Elevated detection frequencies of VC degradation biomarker genes were measured immediately downstream of the accident site (i.e., Sulphur Run). Aerobic VC degradation occurred in all sediment microcosms and coincided with increases of etnC/etnE genes and Mycobacterium, a genus comprising aerobic VC degraders. The conversion of VC to ethene and an increased abundance of VC reductive dechlorination biomarker genes were observed in microcosms established with sediments collected from Sulphur Run. All anoxic microcosms rapidly degraded BA to innocuous products with intermediate formation of n-butanol and acrylate. The results indicate that microbiomes in the East Palestine watershed have natural attenuation capacity for VC and BA. Recommendations are made to improve first-response actions in future contaminant release accidents of this magnitude.

Two new species of Microlaimidae (Nematoda: Microlaimida) from the Continental Shelf off Northeastern Brazil (Atlantic Ocean) with emended diagnosis and dichotomous key

New species of the genera Spirobolbolaimus and Ixonema (Nematoda: Microlaimidae) have been found in sediment samples collected in the South Atlantic, along the Continental Shelf break off Northeastern Brazil. Different to other Spirobolbolaimus species, S. pernambucanus sp. nov. possesses six outer labial setae and four cephalic setae with approximately the same length. Ixonema gracieleae sp. nov. differs from other species of Ixonema in having somatic setae on peduncles. This is the first time that new species of these taxa have been described for the Brazilian coast. An amendment of the diagnosis and a dichotomous key are proposed for both genera.

Occurrence and Contamination Levels of Polychlorinated Dibenzo-P-Dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Soil and Sediment in the Vicinity of Recycled Metal Casting Villages: A Case Study in Vietnam

ABSTRACT This study aims to identify the occurrence and characteristics of PCDD/Fs in soil and sediment samples from secondary copper and aluminum villages in northern Vietnam using the HRGC/MS system. Additionally, it assesses the impact of PCDD/Fs on human health and the potential ecological risks they pose. The residual concentrations of PCDD/Fs in soil and sediment samples collected from the secondary copper Dai Bai village and secondary aluminum Man Xa village were as follows: 0.37 ± 0.29 ng TEQ/kg d.w. (ranging from 0.06 to 0.63 ng TEQ/kg d.w.); 4.88 ± 0.51 ng TEQ/kg d.w. (ranging from 0.512 to 12.17 ng TEQ/kg d.w.); 11.2 ± 5.31 ng TEQ/kg d.w. (ranging from 5.12 to 15.2 ng TEQ/kg d.w.); and 21 ± 12.7 ng TEQ/kg d.w. (ranging from 0.37 to 31.6 ng TEQ/kg d.w.), respectively. The distribution of PCDD/Fs indicated Octa- and Hepta-CDD/Fs as the dominant congeners with high chlorine content. The TEQ levels of PCDD/Fs in all soil and sediment samples were found to be below the allowable limit according to Vietnamese regulations, with the top contributor being 2,3,4,7,8-PeCDF. Samples collected near the production areas exhibited higher levels of PCDD/Fs compared to those collected farther away. The UNEP toolkit was utilized to determine the permissible dioxin TEQ concentrations suitable for livestock farming. The lifetime average daily doses (LADD) of PCDD/Fs via soil ingestion in Man Xa and Dai Bai were calculated as 0.04 × 10−3 and 1.54 × 10−3 pg TEQ/kg d.w. respectively. The relative cancer risks for humans were estimated at 0.05 × 10−12 and 2.05 × 10−12. Furthermore, the ecological risk assessment method indicates that dioxin in all soil and sediment samples near the aluminum recycling craft village had a negative impact on the ecosystem. In contrast, sediment samples taken away from the aluminum recycling craft village and all sediment soil samples in the bronze casting village did not show negative impacts on the ecosystem.

Validation of the GCMS method for the determination of polychlorinated biphenyls congeners in soil and sediment samples

This paper presents the method for monitoring 7 PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) from the US EPA priority, which can also be applied for quantification of PCB sums (28 + 31). The separation of the PCB 28 and PCB 31 was also examined. The GC-MS technique with the HP-5MS column and the accelerated solvent extraction (ASE) were applied. The accuracy and precision of the method were assessed as the recovery (R, %) of the spiked matrices and the relative standard deviation (RSD, %). The obtained recoveries for 17 spiked soil matrices (at the concentration level of 0.05 mg/kg) ranged from 73.8 % to 100.6 % and for spiked sediments from 80.2 % to 106.5 %. The RSD values ranged between 9.7 % and 15 % for soil and from 23 % to 33 % for sediment. The calculation of R and RSD were performed both for individual peaks as well as the sum of PCB (28 + 31). The recoveries of the certified reference materials (CRM) for soil and sediment were also calculated. The river sediment CRM recovery was in the range from 23.3 % (PCB 28 + 31) to 60 % (PCB 118) while recovery for soil CRM varied between 51.6 % for PCB (28 + 31) to 100.6 % for PCB 101. The z-score of the soil and sediment CRMs were in the satisfactory range ±2 for most PCB congeners. It was not possible to separate PCB 28 and PCB 31 for CRM soil.

Legacy and emerging flame retardants in sediments and wastewater treatment plant-derived biosolids

A baseline assessment of legacy and emerging flame retardant chemicals was performed in inland and transitional sediments as well as biosolids emanating from a selection of wastewater treatment plants (WWTPs) in Ireland. A selection of 24 polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and chlorinated organophosphate esters (Cl-OPEs) were quantified in: 81 inland and transitional sediment samples collected during 2023; 39 transitional sediments collected between 2018 and 2022; and 21 biosolid samples collected from 7 WWTPs over 4-month intervals in January, May, and September 2023. Highest concentrations of BDE-209 and several Cl-OPEs were detected in both sediment and biosolid samples, while most PCBs and penta-/octa-BDEs were comparatively low. Moderate levels of PBDEs and Cl-OPEs were detected in Irish sediments compared to similar studies conducted internationally. In biosolid samples, levels of BDE-209 were on the higher end of figured reported worldwide while levels of Σ8Cl-OPEs were the highest relative to comparable international studies. PCBs meanwhile are on the lower end of international levels for both biosolids and sediments. Based on available predicted no-effect concentrations (PNECs), the majority of compounds assessed were found to be of low-risk based on their levels in sediments with the exception of TCIPP (Risk Quotient – RQ = 1.354 = high risk) as well as EHDPP, TEHP, PCB-118, and PCB-52 (RQ = 0.948, 0.576, 0.446, and 0.257 respectively = moderate risk). Similar risk assessment could not be performed on contaminants in biosolids, though levels of BDE-209 were on the higher end of figured reported worldwide (avg = 3155 ng/g) while levels of Σ8Cl-OPEs were the highest relative to comparable international studies (avg8 = 3290 ng/g). As the legacy PBDEs and PCBs have been listed as persistent organic pollutants (POPs) and replacement flame retardants such as Cl-OPEs have been flagged by programmes such as human biomonitoring for EU (HBM4EU) and the NORMAN Network as chemicals of emerging concern, continued monitoring of these moderate and high-risk contaminants in sediments, as well as an investigation of potential contamination of the food chain through land-spreading of biosolids on agricultural lands, would be warranted.

Lithium isotope systematics in an endorheic saline lacustrine system: Insights from Qinghai Lake, China

The study of lithium isotopic (δ7Li) signatures in sedimentary deposits has become a powerful tool to infer past silicate weathering regimes, thus informing our knowledge of the geological carbon cycle and paleoclimate evolution. Sediments from Qinghai Lake, the largest saltwater lake in China (4625 km2), offer an unparalleled archive for investigating the climatic history of the Qinghai-Tibet Plateau. However, prior to leveraging the δ7Li proxy in this context, it is imperative to unravel the mechanisms of lithium (Li) isotope fractionation and elemental cycling within the lake's aqueous and sedimentary systems. In this study, we collected and analyzed samples of Qinghai Lake's water, sediments, and recharge waters (rivers, groundwater, and rainfall) to investigate the processes controlling the δ7Li value recorded in Qinghai Lake sediments.Our data reveal subtle variances in Qinghai Lake water Li concentration ([Li]), ranging from 652 to 873 ng/g, suggesting interactions with iron oxides or suspended matter. The δ7Li signature, however, exhibits remarkable uniformity across the lake at 32.1‰ (±0.4‰). Near the estuary of the Buha River, there is a swift homogenization of [Li] and δ7Li, stabilizing within just 3 km of the inflow. Lake sediments exhibit δ7Li values ranging from 1.5‰ to 6.6‰, exceeding those of the upper continental crust (∼0‰ ± 4‰), yet approximately 30‰ lower than those in lake waters. This significant discrepancy between the δ7Li of lake water and sediments is likely due to the preferential incorporation of 6Li over 7Li during the neoformation of clay minerals.Lithium mass balance modeling for Qinghai Lake, incorporating inputs from river and groundwater (∼46.5 t/a with δ7Li ∼18.3‰) and outputs via clay mineral uptake (∼44 t/a with δ7Li ∼5.1‰), indicates that the lake's Li system is currently out of steady state. The model predicts a gradual rise in the lake's Li inventory, estimated to achieve steady state within 1.2 ka and the δ7Li value of lake water will increase until reaching ∼45‰ assuming constant climate conditions.

Mineralization, geochemical signatures, and provenance of stream sediments on the Jos Plateau, Northcentral Nigeria

This study aimed at determination of mineralization, geochemical signatures and provenance of stream sediments on the Jos Plateau, northcentral Nigeria. Ten (10) stream sediments samples collected were air-dried and subjected to X-Ray Fluorescence analysis. The SiO2 value of 49.79 to 77.03 wt%, Fe2O3 value of 1.30 to 28.84 wt%, Al2O3 value of 5.27 to 18.25 wt%, CaO value of 0.22 to 1.88 wt%, MgO value of 0.12 to 0.92 wt%, K2O value of 0.44 to 2.00 wt% and Na2O value of 0.02 to 0.65 wt%. The low values of CaO (0.22-1.88 wt %) and Na2O (0.02-0.65 wt %) could be associated with the destruction of plagioclase feldspar while low K2O composition (0.44-2.00 wt%) could be associated with the destruction of K-feldspar during weathering. The concentration of MnO (0.06-0.12 wt%) indicates manganite enrichment, the high TiO2 value (0.63-4.25 wt%) shows rutile enrichment while ZrO2 value (0.48-18.48 wt%) indicates zircon mineralization from the underlying lithologies. The high values of pathfinder elements (Y, Zn and Nb) could be attributed to the presence of Older and Younger Granites at the upstream of the study area. Samples 4, 5, 8 and 9 have Thorium (Th) concentrations >15 ppm threshold which point to areas favorable for Th mineralization. Enrichment Factor (EF) ranges from 3.03 to 42.42 indicating moderate, significant, very high enrichment and extremely high enrichment. The Contamination Factor (CF) of 1.27 to 201.03 indicates moderate and very high contamination possibly from geogenic sources. The provenance of stream sediments is associated with felsic and mafic sources