Trace Element Analysis Research Articles

Depositional Environment Conditions and Organic Matter Enrichment Mechanism of the First Member of Upper Cretaceous Qingshankou Formation in the Heiyupao Depression, Northern Songliao Basin

The first member of the Qingshankou Formation (Qing Member 1) is rich in oil and gas resources and represents the first lacustrine transgression period, during which the lake basin area reached its maximum. This study utilizes major and trace element analyses, along with pyrolysis, to investigate the sedimentary environment and mechanisms of organic matter enrichment in the hydrocarbon source rocks of the Heiyupao Depression Qing Member 1. The results indicate that the hydrocarbon source rocks in this area exhibit good to excellent organic richness, mainly comprising Type I and Type II1 organic matter, and are at a high stage of maturity. Furthermore, the paleoclimate conditions during the Qing Member 1 period in the study area were characterized by a warm and humid climate, with an open lake basin and freshwater to brackish water conditions. The water was low in oxygen, suboxic to anoxic, and had relatively high primary productivity. Multiple marine transgressions occurred during the Qing Member 1, transporting substantial nutrients into the lake, which promoted algal blooms in the water. The correlation analysis of TOC content in the Qing Member 1 shale and various indicators shows that the enrichment of organic matter in the study area is primarily influenced by paleoproductivity and paleosalinity, while paleoclimate, paleoredox conditions, and paleowater are not the main controlling factors for organic matter enrichment in the area. Organic matter only accumulates under relatively high salinity and paleoproductivity conditions. Event-driven marine transgressions also play an essential role in enhancing paleoproductivity. Therefore, the organic matter enrichment model in the study area is more aligned with a productivity-driven model. Finally, a comprehensive organic matter enrichment model of hydrocarbon source rocks in the Qing Member 1 of the Heiyupao Depression is proposed.

Trace elements in Alaska's ice seals in the 2000s and 2010s.

Ringed (Pusa hispida), bearded (Erignathus barbatus), spotted (Phoca largha), and ribbon (Histriophoca fasciata) seals are ice-associated seals that are important subsistence resources for coastal Alaska Native people. These seals are also mid- to upper trophic level Arctic predators and primary prey of polar bears (Ursus maritimus). We analyzed concentrations of 19 trace elements in seal liver, kidney, muscle, and blubber, including arsenic, cadmium, lead, mercury, and vanadium due to their potential toxicity. We also measured monomethyl mercury, the more biologically available and toxic form of mercury, in a subsample of seals. We tested for differences in elemental concentrations by seal sex, age, and two periods, 2003-2007 and 2011-2016, to detect environmental trends, assess seal health, and explore trace elements in seal tissues as indicators of seal diet. Trace element concentrations were within ranges that were similar or below that previously measured for these species throughout their range in the Arctic and subarctic. We found relationships between concentration and seal sex or age, as well as differences between periods, with a notable decline over time in magnesium for bearded seal liver and kidney, and ringed and spotted seal liver. Relative concentrations of methyl mercury and total mercury among the four seal species matched known patterns of piscivory and pelagic feeding. Cadmium concentrations were highest in bearded and ribbon seals, possibly due to greater benthic feeding and consumption of squid, respectively. Tissue trace element concentrations from sick seals collected during the 2011-2016 Northern Alaska Pinnipeds Unusual Mortality Event did not differ from those of healthy subsistence harvested seals. Our analysis of trace elements in four Alaskan ice seal species can inform toxicological risk assessments regarding non-essential elements of concern and assessments of nutritional benefits regarding essential elements for seals and for the people and polar bears that eat them.

A simple method for elemental analysis of liquids in sprayed microdroplets by laser-induced breakdown spectroscopy

The study shows that paper spray and laser-induced breakdown spectroscopy (PS-LIBS) analyze trace elements in aqueous solutions, addressing challenges in bulk analysis. Its efficiency highlights its potential for in situ liquid sample analysis.

Geochemical Analysis of Paleocene-Eocene Sediments from Subathu Formation, Dehradun District, Uttarakhand: Implication for Provenance, Tectonic Setting and Paleoclimate

The Palaeocene-Eocene Subathu Formation in the Nilkanth region near Rishikesh, Uttarakhand provides insights into the provenance, depositional environment, and tectonic setting prior to final India-Asia continent collision. Geochemical analysis of major oxides, trace elements, and rare earth elements from shale-dominated sedimentary rocks reveals a complex provenance. Discriminant function plots indicate the derivation of sediments from quartzose sedimentary sources, with minor input from mafic igneous sources. Trace element patterns suggest contributions from felsic igneous rocks, recycled sediments, and subduction-related components. The Chemical Index of Alteration (87.2*Avg.) indicates moderate weathering in the source area under semi-arid paleoclimatic conditions. Tectonic discrimination diagrams indicate that the deposition of sediments from Subathu Formation was occurred predominantly in an active continental margin setting. Rare earth element patterns exhibit varying degrees of fractionation, implying diverse sources ranging from mafic to felsic compositions. This multi-proxy geochemical study sheds light on the evolving paleoenvironmental conditions and sediment routing systems in the western Himalayan foreland basin leading up to the terminal India-Asia collision. Keywords: Geochemistry, Subathu Formation, Provenance, Tectonic Setting, Paleoclimate, Depositional Environment, Himalaya

From microalgae to gastropods: Understanding the kinetics and toxicity of silver nanoparticles in freshwater aquatic environment.

Silver nanoparticles (AgNPs) are increasingly used in various consumer products and industrial applications, raising concerns about their environmental impact on aquatic ecosystems. This study investigated the physicochemical stability, trophic transfer, and toxic effects of citrate-coated AgNPs in a freshwater food chain including the diatom Cyclotella meneghiniana and the gastropod Lymnaea stagnalis. AgNPs remained stable in the exposure medium, with a minimal dissolution (<0.06%) after 24h, indicating that particulate forms dominated during exposure. AgNPs inhibited the growth of C. meneghiniana without significantly affecting chlorophyll-a content or reactive oxygen species (ROS) production. Scanning electron microscopy revealed extracellular polymeric substance (EPS) secretion, which likely formed eco-coronas, reducing AgNPs bioavailability and oxidative damage. However, trace element analysis showed significant depletion of iron, manganese, and nickel, indicating early metabolic stress and redistribution of essential metals to support antioxidant defenses. In L. stagnalis, toxicokinetic analysis showed distinct patterns of Ag uptake and depuration across exposure routes. Waterborne and foodborne exposure resulted in similar and higher Ag accumulation compared to the combined group. Waterborne exposure showed the highest non-eliminable fraction and a bioconcentration factor (BCF)>1, indicating efficient uptake and retention. Foodborne exposure exhibited a biomagnification factor (BMF)>1, despite efficient elimination. Combined exposure had the highest depuration rate, with BCF >1 and BMF <1, reflecting reduced trophic transfer potential. Oxidative stress in L. stagnalis was highest during combined exposure, with increased ROS in hemolymph during uptake. Foodborne exposure caused prolonged immune stress, evidenced by elevated total antioxidant capacity (TAC) and protein levels. In the hepatopancreas, foodborne exposure during depuration led to increased lipid peroxidation and TAC, indicating oxidative and metabolic challenges specific to dietary exposure. These results highlighted the complex interactions of AgNPs with primary producers and consumers in freshwater ecosystems, emphasizing the need for multi-route assessments in nanoparticle risk evaluations.

Environmental risk assessment of the surface sediments based on trace elements analysis from the largest freshwater lake in the southern slope of the Himalaya, Nepal.

Freshwater ecosystems, including high-altitude lakes, can be affected by trace metal pollution derived from a mix of natural sources and anthropogenic activities. These pollutants often collect in surface sediments, with notable concentrations in the deeper areas of lakes. To evaluate the environmental risk associated with metal contaminated sediment in Rara Lake, southern Himalaya, surface sediment samples were systematically collected in November 2018, with a subsequent specific emphasis on determinations of trace element concentrations. Subsequent analysis revealed nine elements exhibiting a descending mean concentrations order: iron (Fe) > manganese (Mn) > chromium (Cr) > rubidium (Rb) > nickel (Ni) > strontium (Sr) > cobalt (Co) > copper (Cu) > cadmium (Cd), of 7205.55mgkg-1, 2290.34mgkg-1, 176.29mgkg-1, 153.78mgkg-1, 51.86mgkg-1, 44.61mgkg-1, 38.89mgkg-1, 29.11mgkg-1, and 0.10mgkg-1, respectively. Comparisons to sediment quality guidelines highlight that Mn, Cr, Cu, and Cd as significant threats to the aquatic ecosystem in Rara Lake. To assess the impact of metal pollution, enrichment factor (EF), geo-accumulation index (Igeo), pollution load index (PLI), and contamination factor (CF) were computed. All metals (except Cd) had Igeo value exceeding 5, displaying strong contamination. EF values for Mn, Cr, Co, and Ni metals were > 10, indicating severe effects of anthropogenic influences. CF and PLI values also indicated significant pollution for most of the investigated sites. Elevated trace element concentrations have the potential to adversely affect water, sediment, and aquatic life, also potentially impacting nutrient cycling and microbial activity. This study enhances our understanding of the metal compositions within Rara Lake sediments and provides a basis for more effective lake management and pollution control strategies. Urgent action by regional governing bodies is crucial to address the early stages of metals pollution, including identification and controlling of pollution sources, by appropriate regulations, optimizing industrial practices, and remediating existing pollution to prevent further contamination and protect the lake ecosystem.

Origin of the Miaoling Gold Deposit, Xiong’ershan District, China: Findings Based on the Trace Element Characteristics and Sulfur Isotope Compositions of Pyrite

The Xiong’ershan district is situated on the southern margin of the North China Craton (NCC) and located within the Qinling–Dabieshan Orogen’s orogenic zone. It is adjacent to the XiaoQinling mining district and exhibits very favorable geological conditions for mineralization, as the district contains numerous gold deposits, positioning it as one of the key gold-producing areas of China. The Miaoling gold deposit is a hydrothermal deposit and is controlled by the Mesozoic nearly NS-trending fault. The ore bodies are hosted in the Mesoproterozoic Xiong’er Group of the Changcheng System of volcanic rocks, with reserves reaching large-scale levels. Pyrite is the main gold-bearing mineral and can be classified into four generations: early-stage fine- to medium-grained euhedral to subhedral cubic pyrite (Py1); medium- to coarse-grained euhedral to subhedral cubic granular pyrite in quartz veins (Py2a); fine-grained subhedral to anhedral disseminated pyrite in altered rocks (Py2b); and late-stage anhedral granular and fine-veinlet pyrite in later quartz veins (Py3). Through in situ trace element analysis of the pyrite using LA-ICP-MS, a positive correlation between Au and As was observed during the main mineralization stage; gold mainly exists as a solid solution within the pyrite lattice, and the ablation signal curve reflecting the intensity of trace element signals showed that gold also occurs as micron-scale mineral inclusions. The trace element content suggested a gradual increase in oxygen fugacity from Stage 1 to Stage 2, followed by a decrease from Stage 2 to Stage 3. The Co/Ni values in the pyrite (0.56 to 62.02, with an average of 12.34) exhibited characteristics of magmatic hydrothermal pyrite. The in situ sulfur isotope analysis of the pyrite using LA-MC-ICP-MS showed δ34S values of 4.24‰ for Stage 1, −6.63‰ to −13.79‰ for Stage 2, and −4.31‰ to −5.15‰ for Stage 3. Considering sulfur isotope fractionation, the δ34S value of the hydrothermal fluid during the main mineralization stage was calculated to be between 0.31‰ and 2.68‰.

Long-Lasting Magmatic, Metamorphic Events in the Cathaysia Block: Insights from the Geochronology and Geochemistry of Inherited Zircons in Jurassic A-Type Granites

The Paleoproterozoic basement underlying the Cathaysia Block remains relatively understudied, and its contribution to the region’s tectonic evolution requires further investigation. In this study, we examined Jurassic Laiziling and Jianfengling A-type granites and identified a significant number of zircon grains exhibiting varied CL imaging characteristics. These zircons yielded four distinct age groups: &lt;100 Ma, 200–100 Ma, 500–200 Ma, and &gt;700 Ma. Detailed trace element analysis revealed that these age groups correspond to different zircon types: metamorphic recrystallized zircons (&lt;100 Ma), primary magmatic zircons (200–100 Ma), and inherited zircons (500–200 Ma and &gt;700 Ma). Through host rock and tectonic setting discrimination, we consider that the inherited zircons have host rocks of S-type granites and basic rocks, and these were formed in subduction-compression tectonic environments. In comparison to local significant geological events in history, we propose that these zircons record multiple tectonic events in the South China Block, including the amalgamation of the Yangtze and Cathaysia Blocks during the Neoproterozoic; an intracontinental orogenic event that occurred during the Middle Paleozoic; and subduction–exhumation processes related to the Paleo-Pacific slab; as well as extensional metamorphic events from the Cretaceous to Tertiary events. A comparison of Hf isotopic compositions revealed that zircons aged 500–200 Ma and &gt;700 Ma share a 2.5–1.6 Ga crustal evolution zone, indicating that multiple re-melting events have occurred within the Paleoproterozoic basement of the Cathaysia Block.

Development of an automated microfluidic system for actinide separation and analysis.

Mass spectroscopy and microfluidic technology, when combined, offer significant advantages in radiochemical analysis sample volume and cost reduction. A microfluidic device designed for efficiency has been developed. This device separates uranium from key trace elements by utilising UTEVA® chromatographic resins and nitric acid solutions of different concentrations for adsorption and recovery. The eluates from this microdevice are then diluted and directed to an inductively coupled plasma mass spectrometry system, enabling direct analysis of trace elements and uranium with minimal operator-sample interaction. This efficient approach greatly reduces the volume of sample required for trace elemental analysis in actinide materials, thereby reducing costs and satisfying the As Low As Reasonably Achievable (ALARA) principle.

Sedimentary, geochemical and reservoir characteristics of the Quaternary submarine fan in the Qiongdongnan basin

The South China Sea holds significant marine oil and gas resources, with the Qiongdongnan Basin being a key area. Submarine fans, as major marine reservoir systems, are crucial for storing natural gas and gas hydrates. However, research on the large Quaternary submarine fan in this basin is limited. Our study examines the importance of Quaternary submarine fans in the Qiongdongnan Basin, South China Sea, with a focus on their development. By utilizing 3D seismic data and core samples, our research aims to analyze submarine fan features and their developmental processes. The submarine fans are divided into four units, with Unit 1–2 submarine fans and internal waterways gradually increasing in size, and Unit 2 to Unit 4 submarine fans and waterway development decreasing in size. Through major and trace element analysis of core samples, we discovered that each major and trace element has different characteristics in different units, such as higher relative contents of Zr and Ti in Units 3 and 4, and higher relative contents of K in Unit 2. Simultaneously microscopic observations and reservoir characteristic parameters are utilized to evaluate the quality of submarine fan reservoirs. We reveal that Unit 2 has the best reservoir quality, followed by Unit 1, and that Units 3 and 4 have poor reservoirs quality This research enhances understanding of the sedimentary evolution of submarine fans in the Qiongdongnan Basin, offers insights into regional geological processes and contributes to global deep-water basin exploration and management.

Rapid Determination of Toxic Trace Metals As, Hg, Tl, and Pb in Hair by Monochromatic Excitation X-ray Fluorescence Spectrometry.

Monochromatic excitation X-ray fluorescence (ME-XRF) spectrometry emerges as a novel technique in trace element analysis, distinguished by its simplicity, rapidity, and efficiency. Its application in forensic toxicology has grown significantly for identifying toxic trace metals in biological samples. This study further expands its utility by developing a method for the rapid determination of arsenic (As), mercury (Hg), thallium (Tl), and lead (Pb) in hair samples. Calibration curves were established using analytical reference samples, and optimal detection conditions were determined and validated. The LODs for As, Hg, Tl, and Pb were 0.03, 0.03, 0.03, and 0.05μgg-1, respectively. Method precision was evaluated through seven parallel analyses of samples within the concentration range of 0.27 to 20.051μgg⁻1, with relative standard deviations (RSDs) consistently below 10%. The feasibility of the ME-XRF technique for forensic toxicology analysis was validated through the analysis of authentic poisoned hair samples collected from the animal experiment.

Formation Mechanism of Muji Travertine in the Pamirs Plateau, China

The Muji spring travertines, located in the Muji Basin in the eastern Pamirs Plateau, represent a typical spring deposit found on plateaus that is characterized by arid and semi-arid climatic conditions. However, its formation mechanisms remain poorly understood. This study aims to explore the recharge processes of the spring, the sedimentary environment, and the genetics of Muji spring travertines through a comparative analysis of conventional hydrochemistry, H-O stable isotope analysis of both spring and river water, and petrographic observation, as well as in situ analysis of major and trace elements present in calcite within travertines. The basin is surrounded by mountains with a topography that facilitates groundwater convergence within it. Carbonate-bearing strata are extensively developed around the basin, which serves as a crucial material foundation for travertine development. It infiltrates underground through fractures and faults, interacting with carbonate rocks to produce significant amounts of HCO3−, Ca2+, and Mg2+. The observed range of isotopic compositions (δ2H, −102.27‰ to −96.43‰; δ18O, −14.90‰ to −14.36‰) in water samples suggests that their primary origin was from glacial and snowmelt sources. The concentration of HCO3− in spring water samples exhibits significant variability, with the highest value being 1646 mg·L−1, which deviates significantly from the typical composition of karst groundwater. During its migration, groundwater undergoes the dissolution of gaseous CO2 derived from deep metamorphic processes, leading to variable degrees of mixing with geothermal groundwater containing elevated concentrations of dissolved components that enhance the dissolution potential of carbonate rocks. Eventually, upwelling occurs along the Southwestern Boundary Fault of Muji, resulting in the formation of linear springs characterized by CO2 escape. The Muji laminated travertines exhibit distinct white and dark laminae, and radial coated grains consisting of micritic and sparry layers. Chemical composition analyses reveal significant differences in the trace and rare-earth element composition, as well as the Mg/Ca ratio, of the two types of travertines. Specifically, the micritic laminae of the pisoid (Mg/Ca = 0.019; Sr = 530 × 10−6; Ba = 64.6 × 10−6) and the dark laminae of the laminated travertine (Mg/Ca = 0.014; Sr = 523 × 10−6; Ba = 48.1 × 10−6) exhibit generally higher Mg/Ca ratios and Sr, Ba contents than the neighboring sparry laminae (Mg/Ca = 0.012; Sr = 517 × 10−6; Ba = 36.6 × 10−6) and white laminae (Mg/Ca = 0.006; Sr = 450 × 10−6; Ba = 35.6 × 10−6). The development of laminated travertines and radial coated grains here is attributed to periodic changes in groundwater recharge induced by seasonal temperature fluctuations, as evidenced by the structural characteristics of the two types of travertines and the trace element analysis of different layers. Algae play a role in forming the dark laminae of laminated travertines and the micritic laminae of pisoids.

An Environmentally Compatible and Less Costly (Greener) Microwave Digestion Method of Bone Samples Using Dilute Nitric Acid for Analysis by ICP-MS.

An environmentally compatible and less costly (greener) analytical method for the digestion of bone meal samples using microwave-assisted dilute nitric acid (HNO3) was developed and optimized. The method, employing a mixture of 1 mL concentrated HNO3 and 4 mL of deionized water, offered a comparable performance to the conventional method using 5 mL of concentrated HNO3. The accuracy of the method was validated by using certified reference material NIST 1486 (Bone Meal); percentage recoveries were within ±15% for all eight certified elements. Statistical analysis revealed no significant differences (p > 0.05) in percentage recoveries between the green and conventional methods for all elements except calcium. The greenness of the developed method was evaluated by using the analytical Eco-Scale, achieving a score of 87, categorizing it as an "excellent green analysis" method. This research highlights the potential for adopting greener practices in trace element analysis that reduce the environmental impact and safety risks associated with concentrated acids.

Morphological and Biochemical Variability of the Fruit and Seed Kernel of Balanites aegyptiaca from Burkina Faso

Balanites aegyptiaca fruits come in various shapes, which can be beneficial for breeding and industrial production purposes. This study aimed to estimate the morphological and biochemical variability of the fruit and seed kernel of B. aegyptiaca based on their shape. Six shapes, namely BLS (big long sharp), BSR (big sharp round), SLR (small long round), BSH (big short hollow), BLR (big long round) and SSR (small short round), were collected. The length, width and thickness of fruits/seeds and the weight of 100 fruits were assessed using a caliper and a scale. Physicochemical properties were determined using official AOAC and AOCS methods. The fatty acids were determined according to the methods of the IUPAC standards. Amino acids were analyzed using the non-derivatization LC-MS/MS method. Mineral and trace element analyses were conducted using inductively coupled plasma emission spectrometry ICP-OES. The results showed significant differences (P&lt;0.001) in the length, width, thickness and weight of 100 fruits across the shapes. The BSH shape had the highest crude fat content and energy value, while the BLS shape had the least favorable profile due to high moisture and acid index. Seventeen fatty acids, 18 amino acids, and 23 minerals were identified, with significant variations observed among the shapes. The predominant fatty acid was cis-9,12-linoleic acid, ranging from 295458.09±100 mg/kg (BLS) to 194138.63±39 mg/kg (BLR). The BLS shape was characterized by the presence of cis-9,12,15-linolenic acid and stearic acid. Cystine was the most abundant amino acid ranging from 615418.83±29 mg/kg (BSR) to 339480.67±81 mg/kg (SSR). Potassium was the most prevalent mineral, followed by phosphorus, calcium, and magnesium. The BLS shape was particularly rich in various minerals. These results highlight the significant morphological and biochemical variability of B. aegyptiaca in fruit, seed and kernel variants.

The Hypothesis of Trace Elements Involvement in the Coronary Arteries Atherosclerotic Plaques' Location.

Background: Coronary artery disease (CAD) is a chronic inflammatory disease with multiple well-known risk factors. Although epidemiological studies report improvements in classical CAD risk-factor control, except for diabetes and obesity, cardiovascular diseases remain the leading causes of morbidity and mortality in the current population. The question regarding the atherosclerotic plaque location in particular arteries remains unanswered. Research on novel possible aspects that could help to properly understand atherosclerosis pathophysiology is essential. This study was based on a body trace-elements analysis, measured in scalp hair samples, as possible co-factors of various enzymes that may be crucial for CAD development. Methods: A total of 133 consecutive male patients with a median age of 71 (65-75) years, who presented with anginal symptoms of CCS class 2.0 (0.3) without previous heart-related interventions, were included in the analysis. The results of the cine-angiography were compared with the demographical, clinical, and laboratory results, followed by scalp-hair trace analysis. The possible predictors for coronary disease locations in the left descending artery (LAD), the circumflex artery (Cx), and the right coronary artery (RCA) were the subjects of this study. Results: Statistically significant differences in the scalp-hair trace elements concentration between the CAD and normal angiogram groups were noticed for magnesium (p = 0.003), calcium (p < 0.001), chromium (p = 0.011), and copper (p = 0.043). The multivariable analysis for epicardial atherosclerotic disease revealed the co-existence of diabetes mellitus (OR: 2.94, 95% CI: 1.27-6.79, p = 0.012) as a possible causative factor for the LAD location. The multivariable analysis for the atherosclerosis location in the Cx artery presented scalp-hair magnesium as a possible predictive factor (OR: 0.98, 95% CI: 0.96-1.00, p = 0.024). The multivariable model for the RCA location of atherosclerotic plaque indicated scalp-hair Zn concentration (0.99, 95% CI: 0.98-1.00, p = 0.002) and serum HDL (OR: 0.61, 95% CI: 0.04-0.09, p = 0.016). Conclusions: Possible hypothetical distinctive pathomechanisms, in particular, coronary artery involvement, in atherosclerosis processes are presented in the male group. Diabetes mellitus was found to be the primary factor for left descending artery disease. The low scalp-hair magnesium concentration was found to be a possible risk factor involved in the circumflex artery atherosclerotic plaque location. The inverse relation between serum high-density lipoprotein, the scalp hair zinc concentration, and right coronary disease was noticed.

India–Eurasia convergence speed-up by passive-margin sediment subduction

The fast increase of convergence rate between India and Eurasia around 65 million years ago (Ma)—from approximately 8 cm yr−1 to a peak rate of approximately 18 cm yr−1—remains a complex geological event to explain1–8, given the inherent uncertainty surrounding the tectonic history and the intricate interplay of forces influencing plate speed9–11. Here we use a combination of geochemical analysis and geodynamic modelling to propose that this rapid convergence can be explained by sediment subduction derived from the northern Indian passive margin. Through isotope and trace element analysis, we find an enhanced contribution of terrigenous sediment melt to the mantle source of the Gangdese magmatic rocks around 65 Ma, concurrent with the acceleration of India–Eurasia convergence. Numerical experiments suggest that subduction of sediments more than 1 km thick covering an approximately 1,000-km-wide ocean basin abutting the northern Indian passive margin starting from 65 Ma could have spurred the increased convergence rate and further led to significant crustal extension, consistent with empirical observations. Our study implies that the acceleration of India–Eurasia convergence marks the arrival of passive-margin-derived sediments, constraining the initial India–Eurasia collision to be around 60 Ma. It further suggests that temporary accelerations in subduction rates might be a common feature at the final stage of continental assembly.

Elemental examination in blood and urine samples of Jordanian children with autism spectrum disorder

Autism Spectrum disorder (ASD) is one of the psychiatric disorders with unknown etiology, which possibly affects children in the first three years of their life. This case-control study was performed to explore the differences in concentrations of 9 elements: sodium (Na), aluminum (Al), potassium (K), calcium (Ca), vanadium (V), manganese (Mn), cobalt (Co), thorium (Th), and uranium (U) in whole blood and urine specimens of children with ASD, neurotypical children, and their mothers. The study investigates the associations between the elements, sex, and severity of ASD. Methods and Materials: The study rincluded 21 children with ASD and 19 age-sex-matched neurotypical children. Elemental analysis was carried out by inductively coupled plasma-mass spectroscopy (ICP-MS). The behaviors of ASD were assessed using the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) and the Childhood Autism Rating Scale (CARS). The results indicated a significant increase of Al (198 ± 87, p= 0.05) and significant decrease of Ca (50 ± 3, p= 0.007) and Mn (10 ± 1, p= 0.004) in blood sample of ASD compared to the neurotypical group. In the urine sample, a significant decrease level appeared in Ca (41 ± 10, p=0.05) of ASD compared to neurotypical. The maternal samples showed no significant difference between ASD and neurotypical. The main finding of this study could help the specialist to diagnose and relieve symptoms of ASD. Thus, the heavy and trace elements analysis is a biomarker for ASD.

The Impacts of Volcanic Activity on Microbial Growth-A Simulation Experiment in the Qiliao Section in Shizhu County, Chongqing, China.

The impact of volcanic activity on microorganisms has always been a hot topic of discussion during geological history. Further studies are needed on the effects of volcanic activity on microbial growth in shale and the differences in nutrients provided by volcanic ash and other weathered rocks. This study's results indicated that TOC contents at the bottom of the shale layer are 1.93-4.44% and 3.0% on average. The TOC contents at the top of the layer are 3.38-5.13% and 4.0% on average. It indicated that TOC contents at the bottom of the shale layer are smaller than the TOC contents at the top of the layer, suggesting that volcanic activity posed a long-term effect on biological growth. Seven different leachate concentrations were set in this experiment as follows: 1/10, 1/100, 1/500, 1/1000, 1/1500, 1/2000, and 1/2500. The results showed that the growth status of Pseudourostyla crassipes was affected by the addition of leachates with different concentrations compared to the control group. Additionally, the synthesis of chlorophyll a by Anabaena pseudoichthyoides was the most efficient with the 1/10 volcanic ash leachate. Through the analysis of major and trace elements in the solution before labeland after cultivation, the main elemental content of Ca2+, Mg2+, Na+, and K+ decreased by 3.8~87.24%, 75.96~92.70%, 86.56~95.67%, and 5.42~20.52% in the solution after microbial growth respectively. The trace elements B, Ba, Zn, and Fe decreased by 27.54~94.39%, 20~82.03%, 70.45~98.29%, and 99%. It was found that the B, Ba, Fe, and Zn elements decreased significantly. The nutrients from volcanic ash are the main factor promoting microbial growth. It can be indicated that the volcanic ash soaking solution has a higher content of nutrients when compared to the solubility of nutrients in volcanic ash compared to that of granite. A higher content of nutrients promotes microbial growth. The calculation results indicate that a volcanic eruption with a quantity of several 1010 m3 has a significant impact on microorganisms, lasting from tens of thousands to hundreds of thousands of years.

Exploitation of Mining Resources in El Argar Culture: Bronze Age Metallurgy in the Hinterland of the Western Betic Cordillera (Southeastern Iberian Peninsula)

ABSTRACTThis research addresses the territorial organisation of metallurgical production during the El Argar Bronze Age (2200–1550 cal bc) in the inner areas of El Argar territory through lead‐isotope and trace element analyses of geological copper ores, archaeometallurgical remains and copper‐based artefacts. Results from 31 mineral and 35 archaeological samples suggest that the exploitation of copper resources in the studied region was significant and had a similar impact than other mining districts of El Argar territory. This, therefore, leads the hierarchical and centralised production model to be questioned. It also appears that the copper ore deposits in the coastal regions that were intensively exploited during the Copper Age were used less intensively in the El Argar period. At that time, copper was mostly procured from ore deposits in the inland areas of El Argar territory: that is, ore deposits within the Alpine orogeny hinterland (inland areas of the Betic Cordillera, from Granada to Baza). Other artefacts were sourced from outside the Alpine geological domain, but still on the fringe of El Argar territory (the foothills of the Sierra Morena‐Linares mining district) or even from ore deposits definitely outside El Argar territory itself (the Los Pedroches Variscan region and elsewhere).

Trace and Minor Element Analysis of Azurite Blues in Fine Arts: Possibilities and Limitations in Provenance Studies.

Azurite, a historical blue mineral pigment, has previously been described to contain certain elemental impurities. These may originate from host rocks, vein fillings, or the primary copper ore mineralization. In this study, azurites (and also green malachites) from three important Central European deposits with a potential of being exploited for pigment usage already in the Middle Ages have been studied, together with azurite from Chessy, France, with a different geological setting. Using electron probe microanalysis and, more importantly, laser ablation inductively coupled plasma mass spectroscopy for trace elemental analysis, several indicators were pinpointed as important for provenance: characteristic elemental fingerprint of the deposit, e.g., elevated lead (Pb) in combination with rare earth elements, may be combined with zinc (Zn)/arsenic (As) ratio (indicating sources of excess Zn in the primary deposit) and the overall amount of metal impurities (suggesting the source mineral of copper for azurite formation). In addition, malachites from the same deposits were found to preferentially incorporate primary ore metal elements as well as Cd, Mg, Mn, or U. Therefore, if azurite pigment contains an elevated amount of malachite as an impurity, it may significantly influence the overall elemental composition. The results obtained on geological samples were applied to two micro-samples of works of art containing azurite-rich layers originating from the 13th-14th and 16th centuries. It was shown that it is highly beneficial to focus on the overall trace elemental composition of the paint layer and not on the admixed mineral grains, as their presence, especially in minute micro-samples, is largely accidental and thus not representative. Although a higher number of samples need to be studied in the future, the newly described criteria made it possible to exclude some of the localities of the employed azurite pigment. This confirmed the key importance of trace elements analysis of mineral pigments for the provenance studies of fine arts.