Major Element Concentrations Research Articles

Sulfuric acid weathering counteracts CO2 drawdown from silicate weathering in mountainous catchments from southwest China

Sulfide oxidation, coupled with carbonate weathering is thought to be a source of CO2 over geological timescales to offset CO2 drawdown from silicate weathering. Its impact on the carbon budget of weathering at the catchment scale is generally constrained by utilizing riverine water chemistry and the isotope value (δ34S) of sulfate. However, the multiple origins of riverine sulfate and the high variability of sulfide-derived δ34S certainly limit the determination of sulfate sources and thus our understanding of the role of sulfuric acid-induced weathering in the carbon budget. In this study, to quantify the carbon budget between weathering by carbonic and sulfuric acids in mountainous catchments (the Yinjiang River, the Shiqian River, and the Yuqing River) in southwest China, a Monte Carlo inversion model is employed for major element concentrations and sulfate δ34S (δ34SSO4). This inversion quantitatively partitions the cations and sulfate between different sources, and further identifies the pyrite-derived δ34S and the flux ratios of alkalinity to dissolved inorganic carbon (ΔALK/ΔDIC). Inversion results reveal that the majority of major cations (>90 %) is derived from carbonate (calcite and dolomite) dissolution, and that riverine sulfate budget is predominately contributed by pyrite oxidation and precipitation. In the Yinjiang River, the average δ34SSO4 is 8.4 ‰ in the upper and middle reaches, but declines significantly to 0.4 ‰ in the lower reaches. In the Shiqian River and Yuqing River, δ34SSO4 mainly cluster around 3.6–5.7 ‰ and 5.5–8.5 ‰, respectively. Inversion results suggest that the primary controls on δ34SSO4 are the variability of lithology and the variation in the proportional contribution of pyrite oxidation to riverine sulfate. In the Yinjiang River, the fraction of H2SO4-driven weathering is highly variable, and higher in the lower reaches than in the upper reaches, attributing to distinct underlying lithology in the catchment (a widespread distribution of coal-bearing strata). The weathering fluxes with 1 < ΔALK/ΔDIC < 2 evidenced that the negative alkalinity flux from carbonate weathering driven by sulfuric acid from both pyrite oxidation and acid deposition counteracts much of the alkalinity flux from silicate weathering. This is implicated on the timescale between marine carbonate precipitation and sulfate reduction (>5–10 kyr and <10 Myr), indicating that weathering in these catchments acts as short-term sinks of atmospheric CO2 but long-term sources of it. Moreover, reanalysis of prior datasets of karst-dominated catchments in China also highlight the important role of pyrite oxidation and acid precipitation in the carbon budget.

Comprehensive study on saline-alkali soil amelioration with sediment of irrigation area in northeast China

To improve the main shortcomings of insufficient nutrients, high salinity and low productivity in saline-alkali soils, this study collected saline-alkali soil samples from Da'an City of Baicheng and sediment samples from the adjacent Qianguo irrigation district, measured their pH values and major element contents, designed and verified the improvement scheme of saline-alkali soil based on geochemical engineering principles. Results indicated that the pH value and various element contents of saline-alkali soil could be adjusted by adding sediment to make it close to reference soil. Both theoretical calculation and experimental determination (soil pH, mineral composition, functional group composition and crop growth) revealed that the optimal mixing ratio of saline-alkali soil and sediment was 2:1. The saline-alkali soil amelioration with sediment of adjacent irrigation areas was effectively, low-cost and environment-friendly. The geochemical engineering principle was applicable to the amelioration of saline-alkali soil, but the mixing ratio of saline-alkali soil and sediment in different areas should vary with the local conditions. Meanwhile, theoretical calculation could basically replace the experimental determination to simplify the actual engineering application process. This saline-alkaline soil amelioration method makes full use of the surrounding natural waste and has the advantage of adapting measures to local conditions.

Major, minor and trace element concentrations in the muscle and liver of a pregnant female Pacific sharpnose shark (Rhizoprionodon longurio) and its embryos

The Pacific sharpnose shark Rhizoprionodon longurio is an abundant shark consumed by human population in Mexico. This study aimed to determine and compare the concentrations of thirteen essential elements (K, S, P, Na, Ca, Mg, Fe, Zn, Se, Cu, Mn, Cr and Co) and eleven non-essential elements (As, Sr, Cd, V, Li, U, Tl, Ag, Sn, Sb and Pb) in the muscle and liver of a pregnant female, fished near the copper mine of Santa Rosalía, and their respective embryos. Major, minor and trace (essential and non-essential) elements were transferred during gestation to embryos. All major elements analyzed had significantly higher concentrations in embryos liver than the pregnant female, except for magnesium. Higher concentrations in embryo tissues than the pregnant female tissues were found for the non-essential trace elements of strontium, lithium, thallium and silver, which indicate an easy maternal transfer of these non-essential elements.

Petrological and chemical characterizations of pristine and reworked phosphorites from Negev, Israel: Insights into industrial usage

Phosphorites are an essential natural resource for producing phosphoric acid, phosphate fertilizers, and phosphate-based products. Detailed characterization and an appropriate assortment of phosphate resources are necessary to identify rocks that are chemically suitable for the phosphate industry. In the present study, we investigated the chemical composition and petrographic characteristics of phosphorites from three phosphate fields located in the same syncline, Zin Negev, Israel. At each site, the succession of pristine and reworked phosphorite layers along 10 m of the section was observed. Based on the chemical and petrographic analysis of phosphorites, it can be concluded that even though all the studied phosphorites were deposited in the same basin under suboxic conditions, the sedimentary settings are varied at each site. These variations resulted in differences in sedimentary structures and chemical composition, including the concentrations of major and trace elements and the abundance of the organic matter fractions. In all studied samples, a decrease in total organic carbon and redox-sensitive trace elements was observed upon the transition from a pristine to a reworked phosphorite phase, while the relative abundance of organic matter fractions remained nearly constant. The results of the present study indicate that, in addition to high-quality phosphorites at anticlinal heights, phosphorites with low organic matter contents in synclines can also be suitable for industrial applications. However, in phosphates, where humic substances represent the main fraction of OM that is located inside carbonate-fluorapatite grains, difficulties in the separation of OM from carbonate-fluorapatite grains during the production process cannot be excluded.

Middle Jurassic ooidal ironstones (southern Tibet): Formation processes and implications for the paleoceanography of eastern Neo-Tethys

The major facies changes documented in shallow-marine sediments of the northern Indian passive margin of Neo-Tethys throughout the Jurassic, from widespread platform carbonates in the Early Jurassic to organic-rich black shales in the Late Jurassic, imply a substantial turnover in oceanic conditions. All along the Tethys (Tibetan) Himalaya, from the Zanskar Range to southern Tibet, a peculiar interval characterized by ooidal ironstones of Dingjie Formation (Ferruginous Oolite Formation, FOF) marks the base of the organic-rich Spiti Shale. This laterally-extensive ooidal ironstone interval is a fundamental testimony of the mechanisms that led to major paleoceanographic changes that occurred in the eastern Neo-Tethys during the Middle Jurassic. In this article, we illustrate in detail the petrology, mineralogy, and geochemistry of ooidal ironstones and the major element contents of the entire Lanongla section. The FOF is characterized by significantly high contents of Fe2O3 (56.80% ± 9.07%, n = 7) and P2O5 (1.72% ± 1.19%, n = 7). In contrast, the Fe2O3 and P2O5 contents average 3.58% and 0.15% in the overlain carbonates of Lanongla Fm., and 5.55% and 0.16% in the overlying Spiti Shale. The ooidal ironstones are mainly composed of iron ooids with a few quartz grains and bioclasts cemented by sparry calcite. The iron ooids consist of concentric dark layers of francolite (carbonate fluorapatite), hence enriched in Ca, P, and F, and bright layers of chamosite, enriched in Fe, Si, Al, and Mg. Precipitation of francolite ensued from oversaturation of phosphorous ascribed to intensified upwelling, high biogenous productivity, and degradation of organic matter, whereas the formation of chamosite reflects enhanced continental weathering and erosion leading to increased Fe input to the ocean during transgressive stages characterized by low sedimentation rate and scarce oxygenation at the seafloor. Modern upwelling zones in outer shelf or slope areas perform similar geochemical characteristics to those as observed in this study. Under the Mesozoic greenhouse background, fluctuating redox conditions induced the alternate growth of francolite under anoxic conditions and of chamosite under suboxic conditions. Ooids were thus formed on the seafloor during continued resuspension and vertical oscillations of the chemocline rather than from interstitial waters after burial. The mineralogy of iron ooids indicates mainly reducing conditions in the water column, suggesting that extensive upwelling along the continental margin of eastern Neo-Tethys contributed significantly to the transition from carbonate deposits to organic-rich black shales during the Jurassic, as testified by the transition from well-oxygenated in Lanongla Fm. To a reduceing condition in Spiti Shale indicated by the Mn/Al ratios compared to PAAS.

Distribution, Source and Contamination Level of REEs and Heavy Metals in Agricultural Soils of Fez-Upstream, Morocco

ABSTRACT Although a few geochemical studies of agricultural soils have been conducted in southern Mediterranean countries like Morocco, such studies examining urban and sub-urban agricultural soils are very rare. The objective is to enable evaluation of different soil contamination indexes, and to identify the anthropogenic and natural sources of potential ecological risks. A sampling of nine soil samples were collected and analyzed to determine concentrations of Major elements, Rare Earth Elements (REEs) and Heavy Metals from agricultural soils of Fez-Upstream, Morocco. The major outcomes were: the average total concentration of REEs is 95.23 µg/g lower than those of the Upper Continental Crust (UCC), at 146.37 µg/g, and world soils at 137.09 µg/g; the ratios of La/Yb, La/Sm and Gd/Yb show that soil samples are enriched by light REEs. Enrichment factor (EF) and geo-accumulation index (Igeo) indicate that there is no enrichment by REEs. EF range from minimal to moderate enrichment. Igeo indicate that soil samples are unpolluted to moderately polluted. The contamination factor and degree of contamination indicate respectively moderate contamination and a low degree of contamination. Otherwise, all sampling sites have PLI values above 1 that indicate obvious anthropogenic pollution due to human activities. The results indicated that REEs contents are reflected by the parent materials. Lastly, it is interesting to note that these obtained results represent the first national data for REEs in Moroccan soils.

Petrography and geochemistry of the Sanaga river sediments, central Cameroon: Constraints on weathering, provenance, and tectonic setting

The Sanaga River (SR), central Cameroon, flows predominantly over metasediments (2.1 Ga), Paleoproterozoic amphibolites and orthogneisses, granitoids from the Adamawa-Yade batholith (AYB), sedimentary clastic rocks of Cretaceous age, and Cenozoic rocks of the Cameroon Volcanic Line. To infer the origin of alluviums and tectonic setting of source rocks, the texture, heavy mineral, major, trace, and rare earth element concentrations of stream sediments were investigated. The very high SiO2/Al2O3 ratios and the ZTR (Zircon-Tourmaline-Rutile) index of SR sediments suggested a high maturity. This interpretation was additionally confirmed by the Th/Sc vs Zr/Sc plot. The Plagioclase- and Chemical Index of Alteration (PIA and CIA) values, the (A-K)-C-N and A–CN–K triangular plots show an intense degree of weathering in the source area. Numerous discrimination diagrams, based on trace elements, indicate that sediments were derived from felsic source rocks mainly granodiorites, granites, and biotite granitoids exposed in the SR watershed. This shows that the metamorphic and volcanic rocks do not significantly contribute to the stream sediments. Paleotectonic investigations using multi-element discrimination plots indicate passive and rift settings for the SR drainage basin. Rift settings were also inferred from downstream sediments of the SR. They are probably related to Proterozoic events including opening of large oceanic basins. The passive and rifted margin settings are supported by the occurrence of rare ophiolitic rocks, which indicate an old oceanic crust.

Geochemical characteristics of the Rajmahal coals in Dhulia North Block, Eastern India: implication to their utilization and environment.

The borehole coal samples of Dhulia North Block from the Rajmahal Basin, Eastern India, were systematically analyzed based on the chemical composition and concentration of major and trace elements (including rare earth elements, REEs) to assess the distribution of REEs and their environmental implications with utilization potential. TheDhulia North Block coals are characterized by the predominant majoroxides of SiO2, Al2O3, and Fe2O3, accounting for 94% of the total ash composition, indicating the presence of quartz, clay-rich minerals, and pyrite. Compared with the average world coal ash, the total REE content in the analyzed samples ranged from 341.0 to 810.4ppm, which is substantially higher. Hot humid climate conditions with intermediate igneous source rocks of the basin were demonstrated by the major oxide ratios (Al2O3/TiO2 < 20) and plots of TiO2 with Al2O3 and Zr. The redox-sensitive elements such as V, Ni, Cr, and Co found in the Dhulia North Block coal indicate that an oxic sedimentary environment existed in the basin when coal was formed. The low sulfur content (1% in most samples) indicates freshwater conditions in the basin at the time of organic matter deposition. The outlook coefficient (Coutl) varies between0.7 and 1.6, indicating that the Dhulia North Block coals are a prospective source of REEs. The Dhulia North Block coals are characterized by low H/C and O/C atomic ratios ranging from 0.56 to 0.90 and 0.10 to 0.22, respectively, and contain type-III kerogens, indicating gas-prone source rock. Further, the basic-to-acid oxide ratio suggested that Dhulia North Block coals were suitable for utilization during combustion processes.

Elemental abundances and isotopic composition of Italian limestones: Glimpses into the evolution of the Tethys

Biogenic limestones from three sections (north, central, and south) across peninsular Italy have been analysed for major and trace elements and Nd, Pb, and Sr isotopic ratios. These data are used to monitor the evolution of the Tethys Ocean from the Triassic through to the Miocene. Limestones’ major, trace, and REE elements contents are consistent with their formation in seawater with little sign of crustal, volcanic, or hydrothermal input. V/Cr and Ce/Ce* ratios indicate their deposition in oxygenated waters. Rb-Sr-Ba discrimination diagram, consistent with the immobile trace element distribution, indicates that limestone deposition took place in either marginal or open ocean environments. Ages based on stratigraphy are in good agreement with the chronostratigraphic Sr curves implying that the Tethys ocean, throughout its history, was in contact with the open, global, ocean system. Although the isotopic values of Sr and Nd are relatively restricted, Pb is extremely variable and highly radiogenic. High Pb isotope ratios characterise limestones deposited during the rifting of the southern Tethyan ocean in the Lower Jurassic and in the Lower Cretaceous, suggesting stronger crustal inputs in small basins. The weighted average, present-day, isotope values (AIL = average Italian limestone) for the Italian limestones, excluding anomalous samples, are 87Sr/86Sr = 0.70785, 143Nd/144Nd = 0.51227, and 206Pb/204Pb = 18.94, 207Pb/204Pb = 15.69, 208Pb/204Pb = 38.66. These values are useful in monitoring the fate of limestones during orogenesis and the role that they may have played in magma genesis.

Geochemical Provenance, Source Area Weathering, and Tectonic Setting of the Bida Sandstone in the Northern Bida Basin, Northcentral Nigeria

This paper aims to determine the geochemical provenance, source area weathering, and tectonic setting of the Bida sandstone exposed at Doko and Jima in the Northern Bida Basin, Northcentral Nigeria. Geological fieldwork was carried out and sandstone samples were collected and analyzed for major element concentrations using X-Ray Fluorescence (XRF) method. Major element abundance shows that the studied sandstone samples consist of SiO2 (average 71.42%), Al2O3 (average 15.16%), and CaO (average 0.26%) constituting about 90% of the bulk rock composition. While P2O5, Na2O, K2O, MgO, TiO2, MnO, and Fe2O3 constitute about 10% of the composition. The results obtained using the Al2O3/TiO2 ratios show that the sandstones derived from intermediate to felsic igneous rocks. The A-CN-K triangular diagram shows that majority of the analyzed samples plotted on the aluminum zone towards kaolinite shows predominantly intermediate degree of weathering except for one sample which falls towards the CN-K line, indicating the different degree of weathering (perhaps an existence of differential weathering in the area). The source area weathering indices which include CIA (68.6%), CIW (71.20%), and PIA (54.66%) further confirms that the sediments have been subjected to intermediate weathering. The K2O/Na2O versus SiO2 tectonic setting discriminant plot shows that the samples are dominantly deposited in the passive margin setting. It is, therefore, concluded that the Bida sandstone analyzed was sourced from predominantly felsic igneous rocks where the degree of chemical weathering was intermediate and in the passive margin setting.

GEOCHEMICAL AND MAGNETIC CHARACTERISTICS OF PLACER GOLD DEPOSITS FROM CENTRAL KALIMANTAN, INDONESIA

Massive tailings have resulted from the extensive use of placer deposits in Central Kalimantan, Indonesia, by artisanal and small-scale gold mining (ASGM) activities. Recently, the placer deposits and their tailings have been exploited for heavy minerals. In this study, geochemical and magnetic analyses were carried out on these deposits to identify the prospect of REE (rare earth element) exploration in the materials already collected by ASGM activities. Samples were collected from ten different locations. For each location, two different fractions were prepared for analyses, i.e. the heavy mineral (HM) fraction and the panned (M60) fraction. All HM and M60 samples were subjected to magnetic susceptibility measurements, but only representative samples were subjected to x-ray fluorescence (XRF) measurements (for Si, Ti, Fe, Zr, and Al) and to inductively coupled plasma-emission spectroscopy (ICP-OES) measurements (for Eu, Tb, Dy, and Sc). The results showed that the concentrations of major elements (Ti, Fe, Zr, and Al) vary significantly from deposits along one river to another, while the concentration of Si is rather similar. Compared to M60 samples, the HM samples have higher concentrations of Ti, Fe, Zr, Al, and Sc, implying that the sluice-box separation enhances the concentration of valuable minerals. Magnetic susceptibility is found to be correlated with Fe and Sc concentrations, confirming the potential use of magnetic measurements as a complementary tool for Fe and Sc exploitation in placer deposits. It is believed that both the source rocks and the sedimentary settings of these deposits determine whether certain elements (Sc, Fe, and Zr) are present or absent in Central Kalimantan placer deposits. The prospect of exploring and exploiting Sc in these placer deposits might augment the ASGM activities in Central Kalimantan.

Temporal evolution of Pu and Cs sediment contamination in a seasonally stratified pond.

There remains a lack of knowledge regarding ecosystem transfer, transport processes, and mechanisms, which influence the long-term mobility of Pu-239 and Cs-137 in natural environments. Monitoring the distribution and migration of trace radioisotopes as ecosystem tracers has the potential to provide insight into the underlying mechanisms of geochemical cycles. This study investigated the distribution of anthropogenic radionuclides Pu-239 and Cs-137 along with total organic carbon, iron, and trace element in contaminated sediments of Pond B at the Savannah River Site (SRS). Pond B received reactor cooling water from 1961 to 1964, and trace amounts of Pu-239 and Cs-137 during operations. Our study collected sediment cores to determine concentrations of Pu-239, Cs-137, and major and minor elements in solid phase, pore water and an electrochemical method was used on wet cores to determine dissolved elemental concentrations. More than 50 years after deposition, Pu-239 and Cs-137 in sediments are primarily located in the upper 5 cm in area where deposition of particulate-bound contaminants was prevalent and located between 5 and 10 cm in areas of high sedimentation, showing a limited migration of Pu-239 and Cs-137. A Factor analysis demonstrated different sediment facies across the pond resulting in a range of geochemical processes controlling accumulation of Pu and Cs. Highest concentrations appear to be controlled by particulate input from the influent canal, dominated by clay, silt, and sand minerals bearing Fe. Elevated Pu-239 in the sediments were observed in areas with high organic matter and higher deposition rate relative to the Pond B system near the outlet indicating strong association of Pu with OM and particulates. Therefore, organic matter cycling likely plays a role in Pu redistribution between sediment and overlying pond water, and deposition in organic rich sediments accumulating near the outlet. Though Pu appears to have been distributed throughout the pond, Cs-137 concentrations remained the highest near the influent canal.

FERROMANGANESE CRUSTS OF THE NORTH PACIFIC

The morphology, mineral and chemical composition (48 elements) of ferromanganese crusts from the northern part of the Emperor Ridge (Detroit, Hanzei, Suizei guyots), the Amlia, Rat and Stalemate fault zones at the north west of the Pacific Plate, as well as volcanic uplifts of the Kuril and Aleutian island arcs were studied. The contents of major, trace and rare-earth elements were determined in the major mineral fractions of ferromanganese crusts (carbonate, oxide manganese, hydroxide ferruginous) which served as sorbents of cobalt and other strategic metals, as well as in the residual fraction. It was established that hydrogenic crusts containing strategic metals that indicate potential economic significance are widespread in the North Pacific. Criteria are proposed for evaluating the contribution of various metal sources to the formation of crusts, which can also be used in the study of other similar objects.

Life history in primate teeth is revealed by changes in major and minor element concentrations measured via field-emission SEM-EDS analysis.

Overcoming the non-specificity of histological accentuated growth lines in hard tissues is an ongoing challenge. Identifying season at death and reproductive events has profound implications for evolutionary, ecological and conservation studies. Dental cementum is a mineralized tissue with yearly periodicity that continues deposition from tooth formation until death, maintaining a record spanning almost the entire life of an individual. Recent work has successfully employed elemental analysis of calcified incremental tissues to detect changes in extrinsic conditions such as diet and climate and to identify two important life-history milestones: weaning and sexual maturity. Here, we employ field-emission scanning electron microscopy and energy-dispersive X-ray analysis to measure the relative concentrations of calcium, phosphorous, oxygen, magnesium and sodium in the cementum of 34 teeth from seven male and female rhesus macaques with known medical and life-history information. We find that changes in relative magnesium concentrations correspond with reproductive events in females and breastfeeding in infants. Additionally, we observe seasonal calcium patterns in 77.3% of the samples.

Chemical characterization of automobile windshield glass samples for major, minor, and trace elemental concentration determination by INAA and its comparison with ED-XRF and DC Arc AES in terms of analytical capabilities and possible applications for glass forensics.

Automobile (car) windshield glass fragments serve as important forensic evidentiary materials and their chemical characterization mainly at minor and trace concentration levels is a key step in forensic investigations. For such glass analysis as well as for forensics, direct solid sample analysis by suitable analytical technique(s) is very important. In view of this, instrumental neutron activation analysis (INAA) using high flux neutrons from research reactor was utilized for chemical characterization of car windshield glass samples. Energy dispersive X-ray fluorescence (ED-XRF) and direct current arc carrier distillation atomic emission spectroscopy (DC Arc AES) methods were also utilized for the analysis of all glass samples for evaluating their analytical capabilities with respect to INAA. A comparative evaluation was carried out with respect to accuracy, precision, and detection limits under quality assurance/quality control (QA/QC). The methods were validated by analyzing certified reference materials (CRMs) G-2 and RGM-1 from USGS and NIST standard reference material (SRM) of sodalime glass (SRM 610). Concentrations of seventeen elements (Na, Ca, Sc, Cr, Fe, Co, Zn, Rb, Zr, Ba, La, Hf, Ce, Eu, Yb, Sm, and Th) were determined in all analyzed glass samples by INAA at major, minor, and trace concentration levels, indicating its capability for potential applications to forensic studies. Grouping study of these automobile glasses was carried out utilizing concentrations of transition elements and rare earth elements (REEs) in conjunction with statistical cluster analysis. In addition, it has been highlighted that some of the transition elements as well as REEs are important markers/discriminating elements for same brand automobile glasses obtained from two different sources/origins.

Zircon U-Pb dating and petrogenesis of the São José do Campestre Granite Complex, NE Brazil: an example of neoarchean mantle-derived post-collisional magmatism

This article discusses the geochemical and petrological evolution of the São José do Campestre granite complex (SJCgr), the last Neoarchean plutonic event so far described in the São José do Campestre massif in NE Brazil. We report field, petrographic, zircon U-Pb dating, and whole rock and mineral chemistry for representative SJCgr samples. Laser ablation zircon U-Pb data indicate that the granite emplacement took place at 2664 ± 13 Ma. The rocks comprising the SJCgr have relatively well-preserved primary textures and fabrics and compositions varying from gabbro to syenogranite. Major and trace element contents reveal a metaluminous, calc-alkaline through transitional to alkaline signature, and LILE- and LREE-enriched series analogous to late Archean sanukitoid and modern arc granitoid. The evolution of the SJCgr is envisaged as follows: (1st) partial melting of a metasomatized mantle (2.5–3.0 GPa, ~85–102 km, 1,000–1,200°C), generating a basaltic to basaltic andesitic magma; (2nd) fractional crystallization (FC) of olivine at mantle or lower crustal depth, leading to the parental magmas of the magmatic series; and (3rd) 40–15% FC of olivine gabbro-norite and olivine monzonite cumulates (400–600 MPa, 15–23 km). The SJCgr shares similarities with post-collisional granitoids and, thus, would represent the last Neoarchean episode of mantle-derived magma in Northeastern Brazil.

Major and trace elements Content in Cannabis Sativa–L cultivated in North of Morocco and Heavy metals health risk assessment

The primary objective of this study was to assess the variation in the elemental composition of Cannabis Sativa seeds cultivated in Northern Morocco and to evaluate potential health risks associated with heavy metals (Cr, Cd, Pb, Ni, and As). We employed Inductively Coupled Plasma–Mass Spectrometry (ICP-MS) to identify and quantify both macro and trace elements in three seed samples. Our analysis revealed the presence of 20 elements in Cannabis seeds, with Mg, K, Ca, P, and Na present in substantial concentrations, while Cr, Zn, Fe, and other toxic elements were detected in trace amounts. Estimations of daily intake (EDI) indicated that Cr had the highest intake, followed by Ni, Pb, As, and Cd. However, Target Hazard Quotients (THQs) for individual metals and the Hazard Index (HI) all remained below 1, suggesting a relatively low risk associated with the consumption of Cannabis Sativa seeds from Northern Morocco. Furthermore, Carcinogenic Risk (CR) values were found to be at a tolerable level. In conclusion, our results suggest that the consumption of Cannabis Sativa seeds from this region poses minimal health risks."

Geochemistry of the Transitional beds between Disang and Barail Successions of the Imphal Valley, Indo-Myanmar Ranges

Major and trace element concentrations were studied from the tansitional beds between Disang and Barail Successions of the Imphal valley, Indo-Myanmar Ranges. Various major and trace element ratios and discrinant diagrams were used to descipher paleoclimate, paleo-redox condition and sedimentary depositional environment of the Disang-Barail Transitional beds. SiO2 vs Al2O3+K2O+ Na2O diagram and Rb/Sr ratios indicates that paleoclimate during the deposition of the sediments changed from arid to semi-arid and humid climate. Ni/Co, V/Cr, V/(Ni+V), V/Sc ratios suggest that these sediments were deposited in oxic, suboxic to anoxic conditions. V/(Ni+V) vs V/Cr diagram suggests paleo-redox environment dominated by sub-reduction to oxidization during Disang –Barail Transitional deposition. The sediments were deposited in transitional to marine depositional environment.

Gabbroic Rocks in Mawat Ophiolite Complex, NE Iraq: Geochemical Constraints on their Tectonogenesis

The Mawat Ophiolite Complex located in north-eastern Iraq represents part of the Iraqi Zagros Suture Zone, located at the border between the Arabian-Iranian plates. It consists of peridotite, gabbro, subvolcanic sheeted dykes and volcanic pillow lava. The geochemical signatures of the gabbro show a significant variation in major elements concentration, low concentrations of TiO2 (0.06-0.36 wt.%), Na2O (0.44-0.98 wt.%), K2O (0.024-0.48 wt.%), P2O5 (0.002-0.009 wt.%) and moderate variations in SiO2 (46.13-53.77 wt.%) with wide ranges and high concentration of Al2O3 (13.87-22.18 wt.%), Fe2O3 (0.04-2.95 wt.%), FeO (2.68-8.76 wt.%), MgO (8.09-14.28 wt.%) and CaO (11.08-17.04 wt.%). The flat REE patterns of the present rocks represent island arc tholeiite (IAT) tectonics and a subduction-related environment. The main features of the magma generated in the supra subduction zone are the enrichment of LILEs and depletion of the HFSEs and the strong negative Nb anomaly. Geochemical evidence indicates that the tholeiitic gabbros were generated in an arc-related tectonic setting. The tectonomagmatic diagrams for gabbros and the very low Ti content propose that the gabbroic rocks of Mawat Ophiolite have island arc tholeiitic (IAT) and possibly boninitic affinities which have a related to the supra-subduction zone (SSZ).

The Contents of Some Essential Major and Trace Elements in Various Types of Processed Milk Products Collected from Benghazi Markets

Milk is an important food; it supplies our body with the essential mineral’s requirements. In this study, some major (Calcium, magnesium, phosphorus) and minor (copper, iron, zinc) essential minerals were determined in seventy-eight random processed milk samples. These samples were collected from different markets in Benghazi city, Libya during 2017. The order of major essential elements concentrations in all milk samples was calcium&gt; phosphorous&gt; magnesium. The mean concentrations of calcium were recorded at 4262 ±2771mg/kg, 5006 ±896mg/kg, 1276 ±319mg/kg and 1231 ±154mg/kg, while mean concentrations of magnesium were 560.1 ±82mg/kg, 419.4 ±153mg/kg, 249 ±7.1mg/kg, 127.7 ±21mg/kg, in powdered, infant formula, evaporated and sterilized milk samples, respectively. Phosphorus concentration varied between 3322-7692mg/kg, 2622-5490mg/kg, 1381-4720mg/kg and 1049-2326mg/kg in powdered, infant formula, evaporated and sterilized milk, respectively. The contents of trace essential minerals, included copper, iron and zinc, were detected in all collected samples. The highest copper content was recorded in powder milk, with a mean concentration 2.13 ±0.84mg/kg, followed by infant formula products, with mean concentration 1.15±0.95mg/kg. The mean concentrations of zinc and iron in milk powder products were detected at 33.48 ±17.4mg/kg and 27.60mg/kg, respectively. The concentration of minor element in evaporated and sterilized milk samples were in concentration lower than 1mg/kg, except zinc in evaporated milk, which varied between 2.80-5.77mg/kg. The contents of essential minerals were agreed with some values that recorded in published results, for same products of processed milk.