Study Of Trace Elements Research Articles

Genetic Type and Formation Evolution of Mantle-Derived Olivine in Ultramafic Xenolith of Damaping Basalt, Northern North China Block

Olivine in deep-seated ultramafic xenoliths beneath the North China Block serves as a crucial proxy for decoding the compositions, properties, and evolution of the lithospheric mantle. Here, we conduct an investigation on olivine (including gem-grade) hosted in ultramafic xenoliths from Damaping basalt in the northern part of the North China Block. This contribution presents the results from petrographic, Raman spectroscopic, and major and trace elemental studies of olivine, with the aim of characterising the formation environment and genetic type of the olivine. The analysed olivine samples are characterised by high Mg# values (close to 91%) possessing refractory to fertile features and doublet bands with unit Raman spectra beams of 822 and 853 cm−1, which are indicative of a forsterite signature. Major and trace geochemistry of olivine indicates the presence of mantle xenolith olivine. All the analytical olivine assays ≤0.1 wt % CaO, ~40 wt % SiO2, and ≤0.05 wt % Al2O3. Furthermore, olivine displays significantly different concentrations of Ti, Y, Sc, V, Co, and Ni. The Ni/Co values in olivine range from 21.21 to 22.98, indicating that the crystallisation differentiation of basic magma relates to oceanic crust recycling. The V/Sc values in mantle/xenolith olivine vary from 0.54 to 2.64, indicating a more oxidised state of the mantle. Rare earth element (REE) patterns show that the LREEs and HREEs of olivine host obviously differentiated characteristics. The HREE enrichments of olivine and the LREE depletion of clinopyroxene further assert that the mantle in the Damaping area underwent partial melting. The wide variations of Mg# values in olivine and the Cr# values in clinopyroxene, along with major element geochemistry indicate transitional characteristics of different peridotite xenoliths. This is possibly indicative of a newly accreted lithospheric mantle interaction with an old lithospheric mantle at the time of the basaltic eruption during the Paleozoic to Cenozoic.

Detection of Essential Trace Element of Chromium by Electroanalytical Methods

A detailed study of essential ultra trace element of chromium present many of industrial waste lakes of western rajasthan. Aconvinent method of electroanlytical technique used for the essential trace element present in the industrial waste water as a polarography method for identification of essential trace element by using concentration of ppm to ppb. According to this method prepare solution of sodium chromate as a stock and identify electroanalytical potential by using as a supporting electrolyte 0.05 M HCl + 0.25 M NaCl give a sharp peak at ࡱ૚ ૛ ൗ = 0.91(V) and result compare with other electroanalytical instrument like UV-Vis Sprctrophotometer, Atomic absorption spectroscopy

Fluorescent sphalerite rich in tungsten, copper, gallium, silver, and other elements from the Cordilleran-style, polymetallic veins of Philipsburg, Montana

Sphalerite from the central, high-sulfidation zone (enargite-stable) of the Philipsburg polymetallic mining district, southwest Montana, displays unusually bright fluorescence (red, orange, yellow, blue, purple, green) under longwave UV light (365 nm). LA-ICP-MS analysis reveals the fluorescent sphalerite has very low Fe (average < 100 ppm) and variable content of other trace elements that correlate to luminescence color banding. Mean/maximum content (in ppm) in fluorescent sphalerite for selected elements are 5.7/7900 Ag, 107/11800 As, 1400/4730 Cd, 917/30400 Cu, 381/5000 Ga, 32/696 Ge, 119/2130 In, 230/8190 Mn, 43/3000 Pb, 16/1700 Sb, and 89/1980 W. This study is the first to document elevated tungsten content (>10 ppm) in sphalerite. Copper is closely correlated with Ga, consistent with the coupled substitution: Cu+ + Ga3+ = 2Zn2+. Similar coupled substitution reactions can be written for Ag+, In3+, As3+, Sb3+, Bi3+, and Ge4+. However, the brightest red fluorescent bands are most closely related to the unexpected presence of W. Sphalerite with high Cu and Ga but lacking W fluoresces yellow and shows a single Raman peak at 349 cm−1 corresponding to pure sphalerite. In contrast, red-fluorescent sphalerite shows the presence of a second peak at 427 cm−1 that increases in intensity with increased W content. We propose that tungsten enters the sphalerite lattice as W6+ via a substitution such as W6+ + 4Cu+ = 5Zn2+ and that this substitution creates lattice strain that results in the anomalous fluorescence and Raman signals. Sphalerite bands with low concentrations of Cu and Ga fluoresce blue or green. Vivid blue fluorescence is displayed by sphalerite with high Cd (>1000 ppm) but low concentrations of all other trace elements. Sphalerite from the low-sulfidation peripheral mines of the Philipsburg district contains high Fe (>10,000 ppm) and does not fluoresce. Nonetheless, this sphalerite is also highly enriched in trace metals, including Ag (mean 2480/max 8660 ppm), Cu (1610/3440), Mn (7020/8100), and Sb (1960/6390). The results of this study underscore the importance of including tungsten in the list of analytes in future studies of trace elements in sphalerite. In addition, a hand-held UV lamp may be a rapid and cost-effective method to screen sphalerite of variable composition in outcrop or drill core. It may be a useful exploration tool to vector towards a high-sulfidation zone of a zoned porphyry or epithermal deposit, when it is present.

Method of obtaining and possibility of using of new complex fertilizers from flotation sludge – potassium-magnesium ore processing wastes

The results of research on properties of cinders obtained by high-temperature roasting of clay-salt waste (sludge) after processing K-Mg ores are presented. Cinders are used as complex fertilizers, ameliorant components and microelement fertilizers. Secondary wastes, after extraction of Pd, Pt, Ag from burnt sludge (cinder), consist of sludge after deslagging of crushed cinder and “tails” after sand enrichment. Mixing these products, moistening, granulating and sintering forms result in a sintering product (CP) that is ready for application as complex fertilizer, ameliorating additive and microfertilizer. A study of the chemical composition and composition of impurities of cinders and CP was carried out. The identity of the composition of cinders and CP has been established. Tests with cinders and CP as a complex of fertilizers, ameliorants and microfertilizers were carried out. The research was carried out on the experimental field of Perm Agricultural Research Institute, on sod-podzolic heavy loamy soil formed on the deluvium of Permian clays, this soil represents up to 70% of the arable lands of the Perm region, the studied crop was potato. The yield of potato when applying cinder as an ameliorant additive was higher by 6.05 t/ha compared to the control (the use of traditional fertilizers provided an increase of 3.56 t/ha). For the first time determination of chemical composition including trace elements studies was fulfilled in potato tubers from unfertilized variants, plots fertilized with traditional fertilizers and plots fertilized with cinders. Two components of tubers – peel and pulp – were analyzed using a mass spectral method, with decomposition in a closed system (autoclave). Most of the elements were characterized by a higher content in the peel (almost an order of magnitude) compared to the pulp. An inverse relationship was observed for P and S, their content was higher in pulp than in peel. In the variant with the use of cinder, a higher content of microelements, especially rare-earths elements, was observed compared to the control. A method for processing sludge to extract Pd, Pt, Ag, results in secondary wastes, that can be used as complex slow-release fertilizers, ameliorating additives and microelement-containing fertilizers.

Provenance and tectonic setting of sandstones of the Lomas Coloradas Formation, Cabullona Group, Sonora, México: Constraints on petrography and geochemistry

The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern Sonora, México, which represent syntectonic sedimentation associated with Laramide-style deformation during the Campanian−early Maastrichtian. The sandstones of the Lomas Coloradas Formation deposited at the upper part of the Cabullona Group. Petrography and geochemical (major, trace, and rare earth elements) studies were carried out on the sandstones to interpret the palaeoweathering, provenance, and tectonic setting of the Lomas Coloradas Formation sandstones. Most of the sandstone modal analysis data plotted in the QFL and QmFLt ternary diagrams fall into the fields of dissected arcs and recycled orogens, respectively. Geochemically the sandstones are classified as litharenites while few samples plot into the arkosic field. The chondrite-normalized REE diagrams for sandstones have LREE-enriched, relatively flat HREE patterns with negative Eu anomalies. CIA values and the A‒CN‒K diagram indicate a low intensity of chemical weathering in the source area. The tectonic setting diagram suggests both arc and rift settings for the studied sandstones. The bivariate and ternary diagrams and elemental ratios suggest a felsic source for the Lomas Coloradas Formation. The average REE patterns of the studied sandstones are comparable with REE patterns of the granite from the Caborca block, the rhyolite and granite of the Tarahumara Formation, and the Mesozoic felsic volcanic rocks. The modeled mixture of 40% Proterozoic granite, 30% Triassic arc, 10% Jurassic arc, and 20% Laramide arc represents the probable source rocks for the Lomas Coloradas Formation.

Tracing Lower Crustal Contamination in Continental Arc Magmas Using Sr–Nd–Hf Isotopes: A Combined In Situ and Bulk Rock Approach Applied to the Adamello Batholith

Abstract The incremental construction of plutons characterises magmatic activity in arc settings, where new continental crust is produced. This polyphasic growth entails interactions with one or more crustal components, which modulate the geochemical and isotopic compositions of the newly formed crust. However, the early stages of magmatism are not always preserved due to obliteration by later magmatic pulses. Spatial migration of magmatism during the construction of the Adamello batholith (Northern Italy) enables the examination of the early pulses of pluton formation, thus allowing a time-integrated study of the relative importance of crystallisation-differentiation and contamination in a continental arc setting. We conducted a detailed textural, major and trace element and Sr isotopic study of plagioclase from the first intrusive pulses of the Adamello batholith, combined with new major, trace element and Sr–Nd isotopic analyses of bulk rock samples across the entire Adamello batholith. We selected well-characterised samples with published CA-ID-TIMS 206Pb-238U ages and Hf isotopic composition for zircons. Strontium isotopes in plagioclase from the same samples were determined by laser ablation multi-collector ICP-MS. The tonalitic samples in the early magmatic stages show elevated but constant Sr isotopic compositions despite large variations in anorthite contents (An90 to An13), indicating that crustal contamination occurred before significant differentiation. Invariant bulk-rock 87Sr/86Sr with variable SiO2 in all superunits of the Adamello batholith further supports contamination preceding significant melt differentiation. Contamination by lower crustal basement lithologies is due to the increasing thermal anomaly triggered by consecutive magmatic injections coupled with the heterogeneous and less restitic nature of the basement in the early stage of the magmatic system (i.e., before consumption of fusible components). In addition, we observe significant variability in crustal contamination proxies (e.g., 87Sr/86Srplag, 87Sr/86Srbulk, εNdbulk, εHfzircon) during the initial phases of magmatism. This variability likely reflects the uneven distribution of positive thermal anomalies in the lower crust during early magmatic stages as well as the diverse lithological and isotopic makeup of the lower crust. The processes identified in our case study are pertinent to continental arc magmatism, particularly where magmas interact with a metapelitic lower crust.

Genome-wide association study of trace elements in maize kernels

Maize (Zea mays L.), a staple food and significant economic crop, is enriched with riboflavin, micronutrients and other compounds that are beneficial for human health. As emphasis on the nutritional quality of crops increases maize research has expanded to focus on both yield and quality. This study exploreed the genetic factors influencing micronutrient levels in maize kernels through a comprehensive genome-wide association study (GWAS). We utilized a diverse panel of 244 inbred maize lines and approximately 3 million single nucleotide polymorphisms (SNPs) to investigate the accumulation of essential and trace elements including cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), selenium (Se) and zinc (Zn). Our analysis identified 842 quantitative trait loci (QTLs), with 12 QTLs shared across multiple elements and pinpointed 524 potential genes within a 100 kb radius of these QTLs. Notably ZmHMA3 has emerged as a key candidate gene previously reported to influence the Cd accumulation. We highlighted ten pivotal genes associated with trace element transport including those encoding heavy metal ATPases, MYB transcription factors, ABC transporters and other crucial proteins involved in metal handling. Additionally, haplotype analysis revealed that eight inbred linesaccumulated relatively high levels of beneficial elements while harmful elements were minimized. These findings elucidate the genetic mechanisms underlying trace element accumulation in maize kernels and provide a foundation for the breeding of nutritionally enhanced maize varieties.

Magmatic and hydrothermal evolution of the superlarge Dashui goldfield in the West Qinling Orogen, China

Gold (Au) is a precious metal that has played an important role in the development of the global economy. It is therefore important to better define the genesis of Au mineralisation as an aid to focus exploration as the consumption of Au increases. The Dashui goldfield contains a super large Au resource of over 120 t (tonnes) in the West Qinling Orogen, central China. Despite several studies have focused on the genesis of the Dashui goldfield, the original physico–chemical natures of magmatic and hydrothermal evolution remain unclear. Biotite and apatite in the mineralised diorite porphyry of the goldfield are sensitive to the changes in the physico–chemical conditions and the evolution of magmatic and hydrothermal fluids, and thus provide important keys to address these issues. Hence, we conducted detailed in–situ major and trace element studies of biotite and apatite from the ore–bearing diorite porphyry in the Dashui goldfield. Our aim is to elucidate the physico–chemical conditions, magma source, and magmatic and hydrothermal evolution processes during the deposition of the gold, and to enhance the understanding of the Au genesis in the West Qinling Au province. Using the geochemistry of magmatic apatite, and magmatic and hydrothermal biotite, we have found that the crystallisation temperature and pressure along with emplacement depth of diorite porphyry were constrained at ∼ 737–791 °C, 1.08–1.73 kbar, and 3.94–6.30 km. The diorite porphyry has the geochemical affinities with calcium alkaline orogenic suites derived from a mixed crustal and mantle source. During the early emplacement of diorite porphyry, the melt had a high oxygen fugacity and was highly enriched in Au. During the late magma crystallisation of diorite porphyry, the magma was enriched continuously in most elements with the Ba/Rb ratios in the biotite varying from 10 to 5, and most of the Au was hosted by pyrite. Additionally, elements were continuously dissolved into fluids generating Cl–rich hydrothermal fluids during the evolution of the magma. During hydrothermal evolution, Au is migrated with As and Sb in the vapour phases of fluids, whereas Au migrated with Cl in the liquid phase. When temperatures dropped to ∼ 200–400 °C, Au started to combine with S and Si in the liquid phase of fluids. Subsequently, hydrothermal fluids interacted with host carbonate to form the Dashui goldfield, Au during this stage was also transported and hosted in magnetite, hematite, and quartz within the carbonate rocks.

Geological and Geochemical Characterization of Variscan Pegmatites in the Sidi Bou Othmane District, Central Jebilet Province, Morocco

The Sidi Bou Othmane (SBO) pegmatite district is situated in the Central Jebilet massif, Western Meseta domain, Morocco. The SBO district is hosted essentially in a volcano-sedimentary series composed of Late-Devonian Sarhlef shales. Pegmatite bodies crop out as dykes, which are oriented from N-S to E-W and are generally variably deformed with ductile and/or brittle structures with ante, syn- or post-kinematic criteria. Petrographic observations of pegmatite dykes show that feldspars (i.e., albite, microcline) are the most abundant mineral phases, followed by quartz and micas, with tourmaline and accessory minerals such as garnet, and zircon also featuring heavily, as well as secondary minerals such as clinochlore, sericite, and illite. The geochemical study of the SBO pegmatites indicates that they have mainly S-type granitic compositions, which are peraluminous granites with calc-alkalic affinities. The study of trace elements indicates that SBO pegmatites were formed in post-orogenic syn-collision context during the Variscan orogeny by the partial melting of argilliferous sediment. They can be ascribed to the muscovite-bearing pegmatite; moreover, they have good potential regarding ceramics. They also contain minerals, such as feldspar, which have been recently assessed as critical raw materials by the European Union.

Hazard estimation in urban home garden soils in an industrial area using microarthropods, soil properties and GIS modelling: an integrated approach.

The use of soil microarthropods as indicators of soil pollution in home gardens of an industrial area has been covered in this study. Soil samples were collected from 25 home gardens in three zones in Eloor during summer and North East monsoon from 2014 to 2018, for the study of soil microarthropods, soil properties, soil nutrients, and trace elements. The relationships among QBS-ar, microarthropod abundance, soil properties, and soil nutrients, were used to estimate the pollution hazard of the industrial area. The microarthropods present in the study area were Coleoptera, Hymenoptera, Diplopoda, and Araneae. A prominent study area feature was the absence of Collembola and Acari. The QBS-ar index score in these regions showed that the home gardens located adjacent to the industrial area showed low soil quality, with soil quality class values ranging from 1 to 2 throughout the study period. Discriminant analysis of soil nutrients with soil properties and microarthropod abundance showed that in Zone 1 and Zone 2, the data in 2018 was very well discriminated compared to other years. The hazard assessment in the Eloor region showed various levels of hazard zonation: Zone 1 with high-hazard and medium-hazard areas, Zone 2 with medium-hazard areas, and Zone 3 with low- and medium-hazard areas. The study is one of the first kinds that have used QBS-ar scores and soil properties along with soil nutrients and trace elements for estimating the level of hazard in home garden agroecosystems and thus points to an easy, simple, and practical approach in the monitoring and management of soil ecosystems.

Insight Study of Trace Elements in PM2.5 During Nine Years in Delhi, India: Seasonal Variation, Source Apportionment, and Health Risks Assessment.

This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM2.5 at an urban location of Delhi (28° 38' N, 77° 10' E; 218m amsl), India, from January 2013 to December 2021. The average mass concentration of PM2.5 throughout the study period was estimated as 127 ± 77µgm-3, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40µgm-3; 24h: 60µgm-3). The seasonal mass concentrations of PM2.5 exhibited at the order of post-monsoon (192 ± 110 µgm-3) > winter (158 ± 70 µgm-3) > summer (92 ± 44 µgm-3) and> monsoon (67 ± 32 µgm-3). The heavy elements, Al (1.19µgm-3), Zn (0.49µgm-3), Pb (0.43µgm-3), Cr (0.21µgm-3), Cu (0.21µgm-3), Mn (0.07µgm-3), and Ni (0.14µgm-3) exhibited varying concentrations in PM2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient(HQ), hazard index(HI), and carcinogenic risk(CR), were computed based on heavy elements concentrations in PM2.5. Elevated HQvalues for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HIvalue exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.

Genesis of Cu-Sn Mineralization in the Shuangjianzishan Super-Large Silver Deposit, Inner Mongolia: Trace Element Constraints from Chalcopyrite and Cassiterite

The Shuangjianzishan silver polymetallic deposit is located in the copper–tin–lead–zinc–silver polymetallic metallogenic belt in the Southern Great Xing’an Range, with silver resources of more than 18,000 t, which is the largest silver polymetallic deposit in Asia. Early studies concluded that the Shuangjianzishan deposit is typically an epithermal Ag-Pb-Zn deposit that lacks a high-temperature mineralization stage. In recent years, with the deepening of research, a large amount of Cu-Sn mineralization has been found in the deep part of the Shuangjianzishan deposit, but it is less studied. The laser-ablation inductively coupled mass spectroscopy (LA-ICP-MS) technique is used to investigate the distribution and substitution of trace elements in chalcopyrite and cassiterite. In this paper, the trace element study of chalcopyrite and cassiterite from the Shuangjianzishan deposit reveals that Sn, In, As, Se, Sb, and Tl mainly exist in chalcopyrite in isomorphic form, while Pb, Bi, and Ni mainly exist in chalcopyrite in the form of mineral inclusions. The enrichment of the high-temperature elements Sn and Se in chalcopyrite, and the deficit of the middle- and low-temperature elements Ga, Sb, etc., reflect that the chalcopyrite in the Shuangjianzishan deposit was formed in a middle- and high-temperature environment, and it also indicates that the early ore-forming hydrothermal solution may be rich in Sn. Fe, In, Co, and Ni mainly exist in cassiterite in isomorphic form, and the content of W in cassiterite is high. There are two main forms, one is isomorphic and the other is wolframite inclusion. Cassiterite has Fe-rich and W-U-poor characteristics, indicating that cassiterite from the Shuangjianzishan deposit was formed under relatively oxidized conditions, and the relative enrichment of elements such as Fe, W, Zr, and Hf indicates that the temperature of cassiterite formation was high. The elemental content and inter-ionic coupling relationships suggest that the cassiterite from the Shuangjianzishan deposit may have an elemental replacement mechanism of W6+ + Fe2+ ↔ 2Sn4+ or Fe3+ + OH− ↔ Sn4+ + O2−. The trace elements in cassiterite of the Shuangjianzishan deposit are rich in Fe and Mn and depleted in Nb and Ta, according to the Fe-W diagram, and the tin mineralization of the Shuangjianzishan deposit belongs to cassiterite–sulfide-type tin mineralization. Chalcopyrite Co/Ni ratios &gt;1 are consistent with the characteristics of chalcopyrite genesis in hydrothermal deposits.

Geochemical and Isotopic Investigation of Carbonate Deposits in the Central Kaladgi Basin, North Karnataka

Abstract Characteristic argillaceous-carbonate sediments covering parts of Belgaum, Bijapur and Bagalkot districts in north Karnataka have extensive deposits of high-grade limestone and have been commercially exploited since 1836. Despite their massive occurrence and commercial importance, the carbonate deposits in the Kaladgi basin have yet to receive enough attention. This study attempts to decipher the genetic aspects of the carbonate deposits occurring in the Neerubudihal region within the central part of the Kaladgi basin. The whole-rock carbon and oxygen isotopic compositions and the major and trace elemental compositions of the studied carbonates indicate that the rocks suffered a weak postdiagenetic alteration and retained the characteristics specific to the original diagenetic environment. The paleosalinity and palaeotemperature estimations reveal the carbonate precipitation in a stable marine environment in the study area with high salinity (av. 125) conditions at an average temperature of ~59 °C. The major and trace elemental studies classify the carbonates as dolomitic limestones and point to the dominance of the sedimentary process in their genesis. The carbon and oxygen isotopic studies suggest that the upper parts of the Bagalkot Group in the Kaladgi Basin had relatively lower organic content and diagenetic alteration than in the contemporary Bhima basin.

Influence of magmatic and magmatic-hydrothermal processes on the lithium endowment of micas in the Cornubian Batholith (SW England)

The Cornubian Batholith (SW England) is an archetypal Variscan rare metal granite with potential for Li-mica mineralization. We present a petrographic, trace element and multivariate statistical study of micas from the Cornubian Batholith granite series and related hydrothermally altered units to assess the role of magmatic vs subsolidus processes and of fluxing elements (F and B) on the Li cycle during the evolution of the system. The mica types are as follows: (1) magmatic, which include Fe-biotite, protolithionite I and phengite-muscovite from the most primitive granites, and zinnwaldite I from more fractionated lithologies; (2) subsolidus, which encompass high-temperature autometasomatic Li-micas and low-temperature hydrothermal muscovite-phengite. Autometasomatic species include protolithionite II, zinnwaldite II and lepidolite, which were observed in the most fractionated and hydrothermally altered units, and occur as replacements of magmatic micas. Low-temperature hydrothermal Li-poor micas formed via alteration of magmatic and autometasomatic micas or as replacement of feldspars, and albeit occur in all studied lithologies they are best represented by the granite facies enriched in metasomatic tourmaline. The evolution of micas follows two major trends underlining a coupling and decoupling between the Li(F) and B fluxes. These include as follows: (1) a Li(F)-progressive trend explaining the formation of protolithionite I and zinnwaldite I, which fractionate Li along with Cs, Nb and Sn during the late-magmatic stages of crystallization, and of zinnwaldite II and lepidolite forming from the re-equilibration of primary micas with high-temperature Li-B-W-Tl-Cs-Mn-W-rich autometasomatic fluids; (2) a Li(F)-retrogressive trend explaining the low-temperature hydrothermal muscovitization, which represents the main Li depletion process. Trace element geochemistry and paragenesis of late muscovite-phengite support that muscovitization is a district-scale process that affected the upper parts of the granite cupolas through acidic and B(Fe-Sn)-saturated hydrothermal fluids associated with metasomatic tourmalinization, which were mixed with a low Eh meteoric component.

Serum zinc concentration and dietary zinc intake in relation to cognitive function: an analysis of the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort.

There are several pathways by which zinc may be a modifiable factor to slow age-related cognitive decline. We investigated the associations between serum and dietary zinc and cognitive impairment in a longitudinal cohort. We used data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort (n = 30,239) and the REGARDS Trace Element Study (n = 2666). Baseline serum zinc concentrations (2003-2007) were measured using inductively coupled plasma mass spectrometry. Baseline dietary zinc intake was measured via the Block food frequency questionnaire. Serum zinc concentrations and dietary zinc intake were categorized into quartiles. The outcome of interest was impairment on the Six-Item Screener (SIS), a measure of global cognitive functioning administered annually. The Enhanced Cognitive Battery (ECB), a more comprehensive series of tests assessing memory and fluency, was administered every two years and considered a secondary outcome. Associations between zinc and incident impairment were assessed using multivariable logistic regression. Among 2065 participants with serum zinc data, 184 individuals developed impairment over 10years of follow-up. In adjusted models, there was no significant association between serum zinc and impairment as assessed by the SIS or the ECB. Among 18,103 participants who had dietary data, 1424 experienced incident impairment on the SIS. Dietary zinc intake was not significantly associated with impairment as assessed by the SIS or the ECB in adjusted models. Findings from this U.S. cohort did not support the hypothesis that serum zinc concentration or dietary zinc intake is associated with the risk of cognitive impairment.

Studies of trace elements and heavy metals in the leaves of Murraya koenigii Linn. (Curry leaves) Plant

Studies of trace elements and heavy metals in the leaves of Murraya koenigii Linn. (Curry leaves) Plant

Ore genesis of the Bayanbaolege Ag-Pb-Zn deposit, NE China: Constraints on LA-ICP-MS studies of cadmium and related trace elements in sulfides

The newly discovered Bayanbaolege Ag-Pb-Zn deposit is located in the Southern Great Hinggan Range metallogenic belt, northeastern China, with 1440 t Ag, 380000 t Zn, 50000 t Pb, and a beneficial component of Cd (806 t Cd) and Ga (211 t Ga). The orebodies of this deposit occur as veins and are hosted mainly by a contact zone between the Permian silty slate and the granite intrusion, and have a closely spatio-temporal relationship with the early Cretaceous granodiorite porphyry intrusion.The mineralization process of the Bayanbaolege deposit can be divided into three mineralization stages including arsenopyrite-pyrite-quartz stage (stage I), pyrite-pyrrhotite-chalcopyrite stage (stage II) and galena-sphalerite-argentite -pyrite-calcite stage (stage III). LA-ICP-MS trace element mapping and spot analyses were conducted on the sphalerite and pyrite in stage III at the Bayanbaolege deposit.LA-ICP-MS trace element mapping and spot analyses were conducted on the stage III sphalerite and pyrite selected from the Bayanbaolege deposit in order to identify the occurrence form and distribution characteristics of critical metal elements, constrain the possible controls on the variation of trace elements, reveal the physicochemical condition of mineralization and provide new insights into the ore genesis. The results show that Ga, Ge, In, Cd, Mn, Cu, Ag and Co concentrations in sphalerite, and pyrite is the preferential host for Ge, As and Ni. The occurrence of Ga, Ge, In and Cd in sphalerite are mainly deposited in form of isomorphism. Physicochemical condition studies suggest that sphalerite precipitated from a medium-temperature hydrothermal system with the range from 190 °C to 291 °C (average at 230 °C) and accompanied with the intermediate fS2. Trace element concentrations of sphalerite are different from that of the MVT, VMS, SEDEX and skarn deposits. The results of this study, combined with the previous geological and physicochemical evidence, indicate that the Bayanbaolege Ag-Pb-Zn deposit deposit is an intrusion-related mesothermal hydrothermal vein-type deposit.

Trace elements (REE + Y) reveal marine, subaerial, and hydrothermal controls on an early Archean habitat for life: The 3.48 Ga volcanic-caldera system of the dresser formation, Pilbara Craton

Host to some of Earth's earliest evidence of life, the fossiliferous lowermost chert-barite sequence (DFc1) in the ∼3.5 Ga Dresser Formation of the Pilbara Craton, Western Australia is interpreted to have deposited within a dynamic volcanic-hydrothermal caldera. To date, three end-member fluid compositions (marine, hydrothermal, and subaerial) have been identified using trace and rare earth elements. However, this data has been limited to a few, single rock units, providing only snapshots at various depositional time intervals, and does not represent a synthesis of habitat evolution over time. Here, we present a systematic trace and rare earth element study of 31 whole-rock samples from 10 lithofacies across the entire stratigraphic sequence. Samples include bedded cherts (silicified chemical and clastic sedimentary rocks), hot spring geyserite and sinter terracettes, jaspilitic chert, and silicified volcaniclastic siltstone. Four lithostratrigraphically-defined assemblages (A1-A4) in DFc1 illustrate a transition from marine (underlying pillowed North Star Basalts, deep marine cherts) to shallow water and subaerial conditions (evaporitic carbonate-chert couplets, hot spring geyserite and sinter terracettes, channelized conglomerates and basaltic-evolved volcaniclastics)(A1-A2), followed by a return to deep marine conditions (jaspilitic chert, volcaniclastic siltstone and sandstone)(A3-A4). Our trace and rare earth element data enhance the four-stage model (reflecting, A1-A4 respectively) as follows: stages 1–2, crustal inflation generated the emplacement of a deep-rooted magmatic chamber, leading to surface uplift and a transition from deep water to hydrothermally-influenced semi-restricted lakes, stromatolites, and subaerial hot springs. Trace and rare earth element patterns of A2 geyserite indicate the circulation of low-temperature near-surface, non-marine geothermal fluids through basaltic to more evolved volcaniclastic rocks. REE + Y patterns of sinter terracettes may indicate the formation of hot spring travertine in DFc1; stages 3–4, hydrothermally-influenced jaspilites and volcaniclastic sediments deposited in marine basins driven by caldera collapse. This stifled stromatolite growth and represents the end of subaerial exposure. This work contributes to ongoing efforts to reconstruct Earth's early life habitats, which inform the search for life on Mars and origin of life studies.

The influence of water, diet, and temperature on 87Sr/86Sr in fin spines of juvenile Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus

Analysis of microchemistry in fish fin spines offers a non-lethal approach to address key questions about life history specific movement and habitat use. Reconstruction of life history is based on chemical changes within calcified structures with an underlying assumption of elemental incorporation relative to environmental concentration. However, information on the relative contributions of water and diet to trace elements in calcified structures of fishes, including fin spines, is limited. Strontium (Sr) is commonly used in trace element studies because of its predictable changes within watersheds, with recent applications showing utility of 87Sr/86Sr for greater spatial resolution. In this study we evaluated the influence of water and diet 87Sr/86Sr on pectoral fin spines of Atlantic Sturgeon A. oxyrinchus oxyrinchus in controlled laboratory experiments. To understand the extent to which water and diet 87Sr/86Sr contribute to levels in fin spines, we exposed fish to one of four treatments for 12 weeks; a control, water spiked with 87Sr, and diet spiked with medium and high levels of 87Sr. To determine the amount of time it takes to elicit a shift in fin spine 87Sr/86Sr following a change in 87Sr/86Sr, fish were maintained in water- or diet-spiked treatments for up to 6 weeks. Lastly, we investigated how temperature may influence fin spine 87Sr/86Sr by holding fish at either 16 °C or 24 °C for 12 weeks. Our experiments indicated water is the primary contributor of 87Sr/86Sr levels in fin spines of Atlantic Sturgeon, and these levels shifted 1 week and 12 weeks following changes in water and diet, respectively. Water temperature did not have an effect on 87Sr/86Sr fin spine chemistry, although sample size was low (n = 3). These results provide guidance for interpretation of 87Sr/86Sr in pectoral fin spines of sturgeon and indicate usefulness of the technique for retrospectively estimating movement and habitat use.

Petrological and geochemical constraints on the magmatic evolution at the Ampato-Sabancaya compound volcano (Peru)

In order to gain insights into continental arc magmatic processes, we have conducted a petrological and geochemical study of major and trace elements and Sr, Nd, and Pb isotopes of the Ampato-Sabancaya compound volcano, which belongs to the Andean Central Volcanic Zone (CVZ). Whole-rock compositions for Ampato and Sabancaya range from andesites to dacites (56.7–69.3 wt% SiO2) and both belong to a medium- to high-K calk-alkaline magmatic series. Ampato-Sabancaya samples are characterized by high contents of large-ion lithophile elements (LILE; e.g., K, Rb, Ba, Th), low concentrations of high field strength elements (HFSE; e.g., Nb, Zr) and heavy rare earth elements (HREE; e.g., Yb), with consequently high La/Yb and Sr/Y ratios. An increase in these ratios is usually interpreted as a result of magmatic differentiation in the presence of garnet in the deep crust. A detailed analysis reveals that the rocks of Ampato-Sabancaya display three different compositional groups. (1) The first, composed mainly of andesites (56.7–59.8 wt% SiO2), corresponds to lavas from the early stage of the Ampato Basal edifice, as well as pyroclastic deposits from the Ampato Upper edifice. (2) The second group corresponds to andesitic and dacitic compositions (60.0–67.3 wt% SiO2) from the Ampato Basal edifice (Moldepampa stage), the Ampato Upper edifice, and the Sabancaya edifice. (3) The third group corresponds to dacitic compositions (65.0–69.3 wt% SiO2) associated with the Corinta Plinian fallout and pyroclastic flow deposits from the Ampato Upper edifice. This last group of dacites, erupted during the Ampato Upper edifice stage, have drastically different compositions from the other groups with Sr/Y (<27) and Sm/Yb (<4.7) ratios lower than other lavas and lacking evidence of amphibole and/or garnet fractionation during their genesis. As a whole, Sr, Nd, Pd isotopic ratios suggest that mantle-derived magmas are significantly affected by assimilation processes during their evolution, due to the thick (65–70 km) continental crust beneath the CVZ in southern Peru. In summary, the magmatic evolution of group 1 and 2 can be explained by a two-step model in which primitive magmas evolved in the deep crust in the so-called melting-assimilation-storage-homogenization (MASH)-type reservoirs by assimilation-fractional crystallization (AFC) processes involving garnet and/or amphibole. Then, amphibole-dominated upper crustal AFC processes and magma mixing are responsible for the geochemical diversity of the main ASCV trend. In contrats, the group 3 dacites followed an upper crustal AFC process (without amphibole) from a different primitive magma, which did not suffer the high pressure, garnet-dominated AFC processes. This evolution highlights the complexities associated to magma genesis and differentiation at continental arcs contructed on a thick crust.