Element Composition Research Articles

Synthesis of the Arts with the Region

Some of Juraj Neidhardt’s most emblematic projects are situated in pristine, non-urban settings. From the Ski House in the pine forests of the Bosnian hills to the Hotel Agava immersed in the Mediterranean shrubbery of the Adriatic Coast, his designs in the landscape were key for him to define his architecture as seeking proximity to and harmony with nature. The design strategy that Neidhardt utilized to realize this ambition was, however, far from constant. While in the 1950s, he relied solely on the “unwritten laws” of the vernacular models to define techniques of new design integration into the specific regional environment, in the 1960s, he produced a series of striking artistic compositions of natural and architectural visual elements, which he described with the notion of “phantasy in tourism.”This paper analyzes Neidhardt’s writings and several projects of the 1950s and 1960s in order to situate his 1960s architecture excursus into the visual arts within the post-war discourse of the “synthesis of the arts.” Under the influence of his and Dušan Grabrijan’s geography-informed understanding of the unity between art, life, and the regional environment and his research in the regional planning of tourism (both presented in the book Architecture of Bosnia and the Way towards Modernity (Grabrijan & Neidhardt, 1957), Neidhardt developed an original architectural language that synthesized not only architecture and sculpture but also the specific regional landscape into one harmonious visual whole. This aesthetic synthesis, however, communicated a deeper synthesis between architecture, geographic region, and modern state economy, facilitated by the emerging regional planning as the ultimate absorption of the total environment into the comprehensive kind of modernism.

The Mobility of Major and Trace Elements in EOC Minerals on Parent Chondrite Bodies

The combined EPMA and SIMS study of the geochemical features of olivine, low-Ca pyroxene and plagioclase in equilibrated ordinary chondrites (EOCs) has revealed the effect of thermal metamorphism on trace element concentrations in EOC silicate minerals. In ordinary chondrites of petrological type 6, trace element composition is homogenized in olivine (Zr, Al, Ti, Ca, Cr, Sr and Ba) and low-Ca pyroxene (Zr, Hf, Y, Ti, Ca, Cr, Sr, Ba and Rb). Trace element concentrations in silicate minerals of petrological types 4 and 5 remain unequilibrated. Although variations in trace element concentrations have decreased, their concentrations in EOC minerals remain unchanged with an increase in the grade of thermal metamorphism. Plagioclase in equilibrated ordinary chondrites displays a consecutive decrease in trace element concentrations with a rise in the peak temperature of thermal metamorphism measured with an olivine-Cr spinel geothermometer. Chondrites of petrological type 4 show a metamorphic temperature of 670–682 °C, and meteorites of petrological type 5 reached equilibrium at a temperature of 687–700 °C. Chondrites of petrological type 6 show the highest metamorphic temperature of 734 °C. The temperatures are generally consistent with the concentric model of parent chondrite bodies.

Holocene onshore/offshore tephra correlation of Mt. Etna, Sicily

The volcanic history of Mt. Etna is mainly known from studies of subaerial deposits and stratigraphy. However, little is known about the offshore deposits, which can provide a more detailed insight into geological and sedimentological processes affecting the flanks of Mt. Etna. During RV Meteor Cruise M178, eight gravity cores were taken offshore across the continental margin east of the volcanic edifice to re-evaluate the volcanic history of pre-historic eruptions and mass wasting events in the area. In total, we investigated 87 marine tephra layers in order to build a marine tephrostratigraphic framework. Based on major element compositions of glass shards, sediment componentry, and petrographic characteristics, 27 layers were identified as primary pyroclastic flow and fall deposits, i.e., directly related to an explosive volcanic eruption. However, most of the remaining tephra layers are interpreted to represent deposits of secondary density currents and are not necessarily related to a volcanic eruption. The marine dataset is complemented by twelve onshore samples taken from major explosive eruptions. Applying geochemical fingerprinting of volcanic glass shard compositions, we correlated eleven marine tephra deposits to seven well-known Mt. Etna eruptions (FV, FF, FG, FL, FS, TV, and M1 eruptions) within the last 12 kyr, which provide valuable time markers in the marine sediment record. Furthermore, we correlated ten marine tephra layers between the marine cores (four individual eruptions) and identified another six primary layers in single cores. In total, we discovered 17 widespread volcanic events in the marine record, including four previously unknown eruptions between 10 and 7.7 ka, which indicate that Mt. Etna was more active than previously thought during this time period.

Elemental Composition and Morphometry of Rhyssoplax olivacea (Polyplacophora): Part II—Intraspecific Variation

Rhyssoplax olivacea is a common mediterranean chiton that exhibits great geographic distribution characterized by variability in its abiotic parameters. Using morphometric measurements of the valves and radula, as well as the element composition of its tooth types from individuals sampled from five different regions across the Hellenic seas, intraspecific differences were examined. The relationship between the abiotic factors and elemental composition was also investigated. Hierarchical clustering on principal components (HCPC) was employed separately on the radular and valve characteristics to determine whether these traits can distinguish regions in the form of clusters, while canonical correspondence analysis (CCA) with ANOVA testing were used to examine the effect of temperature, depth and salinity on these features. Both datasets resulted in three clusters; however, investigation of the radula appeared to better distinguish populations among the examined regions, differentiating Kymi and Pagasitikos. The morphometrics of the valves distinguished the North Aegean Sea (Chalkidiki) from the other regions. The CCA reported that the depth, minimum temperature and average salinity influenced the elemental composition of the radular teeth, while the depth and maximum temperature explained variation regarding the valve morphometrics.

TRACE ELEMENT COMPOSITION OF RAW MATERIALS TAKEN FROM GENUS PULMONARIA PLANTS TO SUBSTANTIATE ITS ANTIANEMIC ACTION

Introduction. Total extracts taken from generative shoots of genus Pulmonaria plants have antianemic activity. At the same time, extracts obtained from vegetative leaves of these plants do not have similar action. Nowadays, there is no algorithm for determining authenticity and quality of herb raw material with using biogenic elements. Creating such algorithm for diagnosing raw materials by microelement composition is an urgent task. Materials and methods. The research objects were generative shoots and vegetative leaves of such plants as: P. officinalis L., P. obscura Dum. and P. mollis Wulf. ex Horn. and mixtures of both types of raw materials. Quantitative determination of elements was carried out by mass spectrometry with inductively coupled plasma. Analyzing obtained results was made using the method of hierarchical clustering. Results. It was established the division into clusters considering all trace elements confirm the species-specificity of the trace element status plants. At the same time raw materials with impurities form clusters different from the cluster formed by hematopoietic complex trace elements contained in the generative shoots of the studied plants. The discovered regularity allows us to consider the cluster, which included the generative shoots as a ref-erence cluster. This reference cluster makes it possible to form an algorithm for checking the raw materials, and its quality Conclusions. As a result of the work, the possibility of using the trace element composition of plants for the standardizing herb raw materials was es-tablished. In addition, the algorithm has been proposed that allows using the content of hematopoietic complex trace elements to determine the au-thenticity and quality of the herb raw material "Pulmonaria herba"

CHANGES IN THE ELEMENTAL COMPOSITION OF THE CHYME AND METABOLIC PROCESSES IN THE RUMEN WHEN EXOGENOUS ENZYMES ARE USED IN FEEDING BULLS

Introduction. Coordination of the processes of scar digestion and metabolism in ruminants is a prerequisite for achieving high efficiency in the use of feed nutrients, improving product quality and profitability of production. The purpose of this study was to evaluate whether the inclusion of the exogenous lipase enzyme in the diet of bullocks in feedlots has a positive ef-fect on physiology, fermentation in the rumen, digestibility and the profile of fatty acids in the rumen. Material and methods. In the experiment, 8 animals were used, divided into 2 groups. the bulls of the control group received the basic diet (RR), the experimental group also received RR with the inclusion of the lipase enzyme at a dosage of 25 g / head / day. The level of volatile fatty acids (VFA) in the contents of the scar was determined by gas chromatography on a gas chromatograph "Crystallux-4000M", determination of nitrogen forms accord-ing to GOST 26180-84. The elemental composition of biosubstrates was studied using atomic emission and mass spectrometry (NPP-ISP and MS-ISP) in the IC of the Central Research Center of the FNC BST RAS. Results. The study of the ratio of LVH in the scar fluid showed that in the experimental group of animals the content of acetic acids decreased by 18.35%, propionic acid – 15.29%, butyric acid – 34.28%, valerian acid – 11.11%, while caproic acid was not found in the experimental group. Nitrogen metabolism in the body showed that the level of total nitrogen in the scar fluid increased by 64.71%, non–protein 53.66%, protein 66.22%, ammonia 78.57% (p 0.05), respectively. Analysis of the biomass of bacteria and protozoa showed that during the experiment, these indicators were higher in the experimental group of animals by 17.07% and 22.22%, respectively, compared with the control. The trace element composition of the scar fluid revealed differences in the mechanism of action of the lipase enzyme on the metabolism of chemicals. There was an increase in the concentration of chemical elements in the experimental group of bulls Ca – by 11.51%, P –17.72%, K – 20.34% (p≤0.05), Fe – 21.31%, Zn – 10.14%, Cu – 23.53%, Se – 39.13%. Against the background of a decrease in Ni – 11.44%, Ba – 14.67%, B – 9.00%, I – 33.33%, Al – 15.71 and Sr – 15.85% (p 0.05). Conclusion. Thus, the study of microbial communities of the LJ rumen, primarily of cattle, is very relevant due to the possibility of rapid diagnosis and prevention of many pathologies of the digestive system associated with improper feeding, which, as a rule, is accompanied by the development of pathogenic and opportunistic microorganisms.

Comparative Study on the Electrocatalytic Performance of ABO3-Based Hexagonal Perovskite Oxides with Different [AO3] Layers.

To systematically investigate the influence of the number of [AO3] layers in the unit cell of hexagonal perovskite oxide on the oxygen evolution reaction performance, we successfully synthesized the three new hexagonal perovskite oxides 2H-BaCo0.9Ru0.1O3-δ, 6H-BaCo0.9Ru0.1O3-δ, and 10H-BaCo0.9Ru0.1O3-δ with the same element composition but different [BaO3] layers via the sol-gel method. Here, 2H, 6H, and 10H refer to the number of [BaO3] layers contained in the unit cell of the BaCo0.9Ru0.1O3-δ system. Experimentally, 10H-BaCo0.9Ru0.1O3-δ, featuring ten layers of [BaO3], exhibits optimal electrochemical activity among the three oxide catalysts, and in situ Raman results under various bias voltages confirm its ability to maintain a high surface crystal structural stability. Notably, as the number of [BaO3] layers increases, the effective magnetic moments and the valence state of surface Co ions in these three catalysts also increase, with the spin configuration of the surface Co ions being in a high-spin state. More importantly, DFT calculations provide the evolution rules of the p-band center (εp) with the number of [BaO3] layers, predicting the electrochemical performance of the BaCo0.9Ru0.1O3-δ system with different [BaO3] layers. Our experimental results offer a distinctive perspective for the future design, synthesis, and application of hexagonal perovskite oxides in electrocatalysis.

Garnet as Indicator of Pegmatite Evolution and Mineralisation: The Case Study of the Koktokay Pegmatites, Altai, NW China

ABSTRACTPegmatite‐related deposits are among the most crucial sources of rare‐metal elements such as Li, Be, Nb, Ta, Rb, Cs and Sn. Despite nearly 2 centuries of extensive study, the mechanism governing the rare‐metal mineralisation of pegmatites remains contentious. Alongside the enrichment of rare‐metal elements in the source region, differentiation processes after emplacement may have also contributed to the concentration and mineralisation of rare‐metal elements. However, compared to fractional crystallisation, limited attention has been directed towards the role of liquid immiscibility in pegmatite mineralisation. In this study, the major and trace element compositions of garnets in the internally zoned (Be‐rich) and un‐zoned (barren) pegmatites from the Koktokay pegmatite field in Altai, NW China, were analysed to evaluate the role of liquid immiscibility in the generation of rare‐metal mineralised pegmatites. The studied garnets belong to the almandine‐spessartine solid solution and are magmatic in origin. The inter‐ and intra‐crystal chemical variations observed for the studied garnets were produced by a combined effect of magmatic crystallisation and liquid immiscibility. The decrease in the spessartine component of garnets from the margins inward and the depleted MREE–HREE distribution patterns of garnet domains indicate the onset of liquid immiscibility, which correlates with the Be mineralisation of the internally zoned pegmatite. Therefore, the chemical variations in garnets from the Koktokay pegmatites suggest a clear genetic relationship between liquid immiscibility and rare‐metal mineralisation, and they are proposed as potential indicators for prospecting rare‐metal ore deposits.

Incompatible trace element geochemistry of the anorthositic achondrite Northwest Africa (NWA) 15118: Relation to diogenites and the Vestan magma ocean

ABSTRACTPetrogenetic models for the howardite–eucrite–diogenite (HED) clan of achondrites have been challenged by the lack of substantial plagioclase in the HED record, which is at odds with the chemical composition of diogenites. Northwest Africa (NWA) 15118, an anorthositic achondrite, displays strong isotopic affinities with HEDs and has been proposed as a lunar‐style primary flotation crust of the Vestan magma ocean. Nevertheless, a geochemical link with known HEDs, particularly diogenites, remains to be demonstrated. We present major, minor, and trace element data for plagioclase and orthopyroxene in NWA 15118. Despite textural evidence for post‐crystallization shock and thermal metamorphism, transect major and minor element data reveal that igneous crystallization trends are preserved. Normalized trace element data reveal depletion in Ti, Nb, Hf, Zr in plagioclase and corresponding enrichment in orthopyroxene. Orthopyroxene in NWA 15118 does not plot on the Y versus Ti array formed by diogenite orthopyroxenes, which have a higher Ti/Y ratio. The calculated melt composition in equilibrium with NWA 15118 plagioclase has lower Ti/Y, Ti/Yb, and La/Sm ratios than melts in equilibrium with diogenite orthopyroxenes; differences in the melt compositions cannot be accounted for by the choice of partition coefficients or by single‐stage magmatic processes. Therefore, we argue that NWA 15118 and diogenites are not complementary cumulates that crystallized simultaneously from a global Vestan magma ocean. Furthermore, the modeled evolution curve of such a magma ocean does not produce the composition of NWA 15118 plagioclase equilibrium melts in Ti‐Y‐Yb space, indicating that NWA 15118 is unlikely to have been a primary flotation crust of a global magma ocean. Our findings suggest that the incompatible trace element composition of NWA 15118 likely reflects more complex, multistage magmatic processes and/or source heterogeneities than envisioned in geochemistry‐based HED petrogenetic models proposed to date.

Biosynthesis, characterization of Ag2O nanoparticles for enhancement of antioxidant and photo degradation activities

Silver oxide (Ag2O) nanoparticles were synthesized via Biosynthesis methods using Croton macrotachyus leaf extract silver sulphate (Ag2SO4) was used as precursors and the extract was used in the reactions as reducing, stabilizing and capping agents which is a very easy and inexpensive synthesis method. Metal oxide nanoparticles characterized using UV–visible, TGA, Fourier transform infrared(FTIR),powder X-ray diffraction(XRD), X-ray photoelectron(XPS), and Scanning Electron Microscopy(SEM) with Energy Dispersive X-Ray(EDX) and Transmission Electron Microscopy(TEM), High Resolution Transmission Electron Microscope(HRTEM), and Selected Area Electron (SAED) which is used for determination of crystalline size, morphology,particle size and oxidation state with composition of elements in the sample. Metal oxide nanoparticles have a significant photo catalytic performance under visible light source confirmed that study supported Ag2O spherical structure, which exhibits enhanced photo catalytic activity and anti-oxidant activities as well as the size of the Ag2O nanoparticles was between 16 nm and 21 nm from the XRD(Scherrer equation),SEM & TEM) imaje software and Photo catalytic activity of Ag2O NPs were assessed against methylene blue (MB) dye degradation under natural sunlight illumination for 60 min. This sustainably photo degraded in direct solar irradiance with remarkable degradation percentage which is greater than 96.35 % and Scavenging activities Ag2O nanoparticles enhanced DDPH scavenging activities was 88 %

Fabrication, characterisation, physicochemical and biological studies of gelatin/PVA/ silk fibre with manganese substituted hydroxyapatite scaffold for bone tissue engineering application

In recent years, researchers have been aiming for the development of multifunctional materials to repair bone tissue. The development of metal, ceramic, glass, and composite implants is the subject of interest in bone tissue engineering. Among these, HAP (ceramic) is either combined with other components, such as polymers or doped with ions to give improved properties or to add novel characteristics. The present study is focused on fabricating a novel scaffold with the required properties. Here gelatin/PVA/SF-Mn-HAP (MGPS) was fabricated by electrospinning to prepare a nano-level scaffold. The manganese-hydroxyapatite (Mn-HAP) was prepared by hydrothermal method. The nano scaffold was fabricated using various wt % (20, 40, 60) of Mn-HAP (Ca5-x Mnx (PO4)3 OH) (x = 0.1, 0.5) with gelatin/PVA/silk fibre. The fabricated nano scaffold phase formation was confirmed by X-ray diffraction (XRD), the functional group belonging to the nano scaffold was confirmed by Fourier transform infrared spectroscopy (FTIR), the topography of the nano scaffold was seen by scanning electron microscopy and the composition of elements was noted from energy dispersive X-ray analysis (EDAX). From the results, the fabricated scaffold MGPS 16 (60 wt% of Mn-HAP (x = 0.5 M) with gelatin-PVA-silk fibre) showed the highest tensile strength of 95.61 MPa. The antimicrobial activity of MGPS 16 showed the zone of inhibition against S. aureus – 62 ± 1.36 mm,E. coli – 71 ± 1.24 mm and C. albicans – 70 ± 1.22 mm. The hemolytic (%) of the MGPS 16 was 1.86 %. The SEM images of biomineralized samples showed the formation of apatite on the surface of the nano-composite.

Triassic–Jurassic alkaline magmatism in the Ivrea-Verbano Zone, Southern Alps: A zircon perspective on mantle sources and geodynamic significance

The Ivrea-Verbano Zone (IVZ; western Southern Alps) consists of a distinctive sequence of the lower continental crust of the Adriatic plate, extending down to the subcontinental lithospheric mantle. It is characterized by a large variety of intrusive bodies of variable geochemical composition and age, offering a unique insight into the evolution of mantle-derived magmatism in post-collisional and extensional geodynamic settings. In this study, we characterize a suite of alkaline dykes intruding a mantle massif – the Finero Phlogopite Peridotite in northern IVZ. These dykes include zircon-bearing diorites and anorthosites, mainly composed by HFSE-rich amphibole and phlogopite, albite (>90 vol% in anorthosites) and apatite. Zircon, monazite, ilmenite, titanite, Nb-rich oxides, and carbonates are common accessory minerals. Additionally, a “composite” diorite dyke containing both HFSE-rich and HFSE-poor amphiboles was investigated. The study is aimed at providing new trace element, UPb geochronological and LuHf isotopes dataset on zircon from these alkaline dykes, to refine the understanding of their mantle source characteristics, emplacement age and geodynamic implications. The trace element composition of zircons from the studied dykes points to segregation from melts with alkaline to ultra-alkaline affinity. Concordia UPb ages of zircon from the alkaline diorite dykes span from 221 to 191 Ma, which are interpreted as the result of multiple crystallization/recrystallization stages related to different magmatic pulses. Conversely, zircon from anorthosite and composite diorite dykes yield a narrow time range of 198–202 Ma, highlighting the occurrence of a magmatic pulse around ca. 200 Ma. The εHf(t) values (+13.4 to +5.7) of zircon from the alkaline diorite dykes are significantly more positive compared to the values in those from anorthosite and composite diorite dykes (+4.2 to −0.4), suggesting that the parental melts were derived from heterogeneous asthenospheric mantle sources with low to moderate amount of recycled continental crust components. Our data and reappraisal of the literature indicate that the IVZ experienced a protracted period of alkaline magmatism from ca. 235 Ma to 185 Ma. The melts migrated along mantle shear zones during the Triassic-Jurassic lithospheric extension. Different pulses of alkaline magmatism were associated with relevant extensional tectonic stages recorded by the continental crust, presumably triggering a passive uplift of heterogenous asthenospheric reservoirs over a front of at least 500 km. This tectono-magmatic cycle is a precursor to the focused rifting stage which caused the opening of the Jurassic Alpine Tethys, enhancing Pangea fragmentation.

Geology and antimony mineralization of the Yangla polymetallic orefield in northwestern Yunnan, SW China: Trace element geochemistry of sulfides and calcite

The Yangla is the largest and highest-grade antimony deposit (10 kt Sb @ 14.87 %) in the Jinshajiang suture zone, northwestern Yunnan (SW China). Pyrite and stibnite are the main sulfides, and calcite is the main gangue mineral in the antimony ores. Antimony mineralization can be divided into three stages: pre-ore stage pyrite and quartz, syn-ore stage (incl. early, main and late sub-stage) stibnite-pyrite-calcite-quartz, and supergene stage valentinite and limonite. The trace element compositions of the three pyrite and two stibnite generations have been analyzed by (LA-)ICP-MS here. The bulk ore-related calcite trace element compositions were also measured by ICP-MS. Trace element correlations and principal component analysis (PCA) show that the majority of trace elements occur as solid solution and micro-/nano-inclusions in pyrite and stibnite. In pyrite, the Sb substitutes into the crystal lattice with Tl, Cu and Ag via (Tl++Cu++Ag+) + Sb3+ ↔ 2Fe2+. Gold occurs as invisible gold (Au+) and enters pyrite via the coupled substitution of As3+Au3+□ ↔ 3Fe2+ and/or As3+Au3+□ ↔ 3Cu2+. In stibnite, the Cu, Pb and As enter the crystal lattice via the coupled substitution of 2Sb3+ ↔ Cu+ + Pb2+ + As3+. Trace element features of calcite are highly similar to the Devonian Linong Formation (2nd member) marble, suggesting that the ore-forming fluid is closely associated with the marble. Syn-ore calcite is characterized by its higher Fe, Mn and MREE concentrations than the pre-/post-ore calcite, and can be regarded as a geochemical fingerprint for metallogenic prediction. The δCe (0.67–0.83, avg. 0.75) and δEu (1.40–2.51, avg. 1.89) values suggest that the antimony precipitation occurred under reducing to weakly oxidizing conditions. The atomic Yb/Ca, Yb/La, Tb/Ca, and Tb/La ratios of the syn-ore calcite imply that the antimony mineralization can be attributed to hydrothermal genesis. This deduction is also supported by that data of pyrite Ⅰ, Ⅱ, and Ⅲ mainly plotted inside the hydrothermal fields in the Co/Ni, As/Ag, Sb/Bi and Co-Ni-As discrimination plots. The Yangla stibnite ore samples mimic stibnite from typical hydrothermal mineralization systems (e.g., Woxi Au-Sb-W deposit, South China) in the Cu vs. Pb plot, which further supports a hydrothermal origin of the antimony. Therefore, we propose that the hydrothermal Sb mineralization is closely related to the Devonian carbonate rocks at Yangla.

Reappraising the eruptive history of the Alchichica Maar Volcano (Mexico) based on Sr–Nd isotopes: Understanding the role of the magma source region on the growth of small-volume volcanoes

Alchichica Maar is in the eastern sector of the Trans-Mexican Volcanic Belt, where volcanics range from basalts to rhyolites, with 87Sr/86Sr and 143Nd/144Nd values between 0.70293 to 0.70447 (εSr = −21.1 to −4.5) and 0.512733 to 0.512949 (εNd = +3.4 to +6.2), respectively. In this study, Nd and Sr isotopic data and new major and trace elements compositions are provided for the lava flow, the scoria cone, and the phreatomagmatic deposits composing Alchichica Maar Volcano. These results are used in combination with published data to reexamine its eruptive history, though to be formed by more than one eruptive event. The cogeneticy of the magmas that fed the eruptions of these deposits is examined to infer the role of the deep magma source region and post-magmatic alterations on the construction of the Alchichica Maar magmatic system. Alchichica samples present 87Sr/86Sr values between 0.70387 and 0.70447 (εSr = −9.0 to −0.4) and 143Nd/144Nd values from 0.512749 to 0.512773 (εNd = +2.0 to +2.8). While the 87Sr/86Sr values suggest a slight increment in radiogenic 87Sr from the pre-maar lower lava flow to the upper maar eruptions indicative of magma contamination within the upper crust and by hydrodynamic mingling during the phreatomagmatic phases, the slight variation in Nd isotopes suggest an overall homogeneous source where small batches of magmas formed episodically to feed monogenetic eruptions, which subsequently yielded the pre-maar lava flow, the pre-maar surge, the scoria cone, and the maar units. This study reinforces the idea that an already “tapped” source region of a monogenetic volcano may become fertile again, and new eruptions can occur from near or old vent sites. It also highlights the hazardous potential of small-volume volcanoes.

Zircon U[sbnd]Pb ages, trace elements, and Hf isotopes establish a genetic link between volcanic ash beds and porphyritic intrusions during early Silurian in the South China Block

The provenance of the Late Ordovician to Early Silurian volcanic ash beds (VABs) in the South China Block (SCB) remains debated. In this study, we provide new zircon UPb age, trace element, and Hf isotope data of bentonites, crystal tuffs, and porphyritic intrusions from the Longmaxi Formation of the Dabashan area in the northern margin of the SCB with a view to investigate the composition, tectonic setting, and source of their parent magmas. The zircon UPb ages show that the volcanic eruption and magma emplacement occurred in the Early Silurian (ca. 440–434 Ma). The zircon trace element compositions are consistent with A-type parent magmas formed in intraplate extensional settings. The positive εHf(t) values (+1.7 to +6.9) of zircon indicate an enriched mantle source for the magma, with possible crustal input. The similar UPb ages, trace element compositions, and εHf(t) values of zircon grains from VABs and porphyritic intrusion in the Dabashan area suggest that their parent magmas shared similar sources. These A-type parent magmas could have originated in intraplate extension settings on the passive margin of the northern SCB during the subduction of the Proto-Tethys Ocean towards the North Qinling Terrane. Our results suggest that the Paleo-Tethys oceanic basin did not open before the Early Silurian (ca. 434 Ma) in the Dabashan area.

Magnesium isotope constraints on the role of recycled carbonate-rich sediments in the formation of ultrapotassic magmatic rocks at a continental arc setting

The formation of orogenic ultrapotassic magmatism in a subduction setting is still unclear as it requires various co-processing mechanisms. To address this problem, especially to investigate the role of carbonate metasomatism in the mantle source, whole-rock Mg-Sr-Nd isotopic compositions have been measured for ultrapotassic magmatic rocks from the Central Pontides arc, northern Turkey, one of the rare examples of subduction-related ultrapotassic magmatism. These ultrapotassic rocks have relatively low (87Sr/86Sr)i (0.70461–0.70687) and εNd(t) (0.3 to 2.6) values and display much lower δ26Mg values (−0.73 ‰ to −0.19 ‰) than the normal mantle. The petrological and geochemical characteristics of the Pontide Ultrapotassic rocks (PUR) indicate that the low δ26Mg values do not result from surficial weathering, diffusion, or magmatic differentiation, but rather reflect the presence of distinct metasomatizing agent in their mantle source. The low Hf/Hf*, Ti/Ti*, Fe/Mn and Ti/Eu ratios, high Ca/Al and (Na2O + K2O)/TiO2 ratios, and lack of significant correlations between δ26Mg and Fe/Mn or (Gd/Yb)N suggest that the low δ26Mg values cannot be reconciled with the contribution of recycled carbonated eclogites, but are induced by the addition of carbonate-rich sediments to their mantle source. This interpretation is also supported by the significant (La/Yb)N vs. Ti/Eu and Hf/Sm vs. CaO/Al2O3 correlations for the ultrapotassic rocks. Using two end-member mixing calculations of MgSr isotopic compositions, the mantle source of PUR is constrained to contain varying proportions of carbonates, mostly of dolomite composition. The addition of carbonate-rich sediments to the mantle may have occurred at depths of 100–150 km as indicated by the trace element compositions of PUR. In this regard, the enrichment of K and other large ion lithophile elements in the ultrapotassic rocks can be induced by the contribution of silicic sediments. Meanwhile, carbonatitic melts can be formed through the partial melting of carbonate-rich sediments in the subducting oceanic slab, which then reacts with the overlying mantle to form carbonated peridotite that serves as the source of ultrapotassic rocks with low-δ26Mg, low-silica, and high LREEs. This study reports for the first time the Mg isotope data of ultrapotassic rocks formed in a continental arc setting and documents that carbonate-rich sediments play an important role in creating such rocks. Future work is needed to test whether this process is common in both oceanic arc and continental arc settings.

Potential engineering applications of volcanic scoria from Mount Cameroon area, Central Africa: evidence from petrography and geochemistry

This study was initiated to explore the suitability of volcanic scoria from Mount Cameroon along the Cameroon Volcanic Line (CVL) in engineering applications. The mineral composition has been obtained through thin sections observation and XRD method. The XRF analytical methods have been used to determine major element composition. The studied rocks are dark gray to reddish in color with a vacuolar structure and porphyritic microlithic texture recalling the Strombolian dynamism. They are mainly made up of pyroxene, olivine, plagioclase, opaque minerals, quartz, magnetite and iddingsite. The presence of phenocrysts of olivine and clinopyroxene is due to mantle contamination. The main chemical components of scoria of Mount Cameroon are silica, alumina, iron and calcium oxides. The abundant vitreous phases are responsible for the acidic character revealed by high SiO2 + Al2O3 contents. Fe2O3, MnO and MgO are hosted by ferromagnesian minerals while SiO2, Al2O3, K2O, NaO and P2O5 are found in acidic vitreous phases. The mineral and chemical composition of the scoria of Mount Cameroun is similar to those of scoria previously studied around the world. They can be used as absorbents for metals because of their high adsorption capacity and affinity for metals. The high SiO2 + Al2O3 + Fe2O3 contents and low LOI values show that the scoria from Mount Cameroon are suitable to the use in cement and concretes. They can improve the resistance to sulfate, and chlorite and alkali silica reaction. According to the chemical composition, the rocks are conforming to French standard NFP18310. Their high CaO contents are favorable to improve the quality of scoria blended cements.

Macro, Trace and Toxic Element Composition in Liver and Meat of Broiler Chicken Associated with Cecal Microbiome Community

The current study presents a meta-analysis of the detailed relationship between the composition of 25 essential and toxic elements in chicken tissues examined by ICP-MS and the gut microbial community analyzed using NGS techniques. The examination of chicken liver and meat revealed typical elemental compositions, called the “elementomes”. The α-elementomes showed high contents of macro elements (Na, K, Mg, Ca, P), majority trace elements (Sr, Se, Mn, Fe, Co, Cu, Zn) and some toxic elements (B, Pb, Ni, Cd); β-elementomes indicated accumulation of Si, V and Cr; γ-elementomes indicated accumulation of Al, As and Hg. Characterization of the microbiomes’ structure showed two distinct enterotypes, designated “microbiome patterns”; the first was enriched in the phylum Bacteroidota, and the second was dominated by Bacillota and coupled with members of the phyla Actinomycetota, Cyanobacteriota and Thermodesulfobacteriota. A comparison of elementomes and microbiomes demonstrated a clear correspondence between the α- and γ-elementomes belonging to the Bacteroidota-enriched pattern, while the β-elementome was predominantly found in chicken groups belonging to the Bacillota + ACT pattern. This insight proposes a novel strategy to improve deficiency or excess of certain elements in the host by gut microbiome modulation, which needs to be verified with further in vivo experiments.

East–west-trending tearing of the Indian slab beneath the eastern Tibetan Plateau: Insights from Eocene–Oligocene potassic adakite-like granites in western Yunnan

Large-scale Eocene–Oligocene potassic adakite-like granites predominantly occur between 25° N and 27° N, north of the Ailaoshan suture in western Yunnan, eastern Tibetan Plateau. However, limited interpretations of their spatial characteristics hinder our understanding of the tectonic evolution in this region. Herein, we present new petrographic analyses, zircon UPb ages, whole-rock major and trace element compositions, SrNd isotopic data and zircon Hf isotopic mapping for these granites. Zircon UPb ages indicate that the adakite-like granites were emplaced at approximately 37.1–33.6 Ma. These granites exhibit high-K calc-alkaline compositions, enriched light rare earth elements and significant depletion in heavy rare earth elements, characterised by high Sr contents (667–1795 ppm), Sr/Y ratios (35–158) and La/Yb ratios (13–62), alongside low Y (8.2–23.3 ppm) and Yb (0.71–1.13 ppm) contents. The adakite-like granites possess high initial 87Sr/86Sr ratios (0.70596–0.70687) and low εNd(t) values (−5.73 to −0.65), with two-stage depleted mantle model ages (TDM2) ranging from 1.3 to 0.9 Ga. Their zircon εHf(t) values range from −5.1 to +0.7, with Neoproterozoic TDM2 ages of 1.4–1.1 Ga. Notably, these adakite-like rocks in western Yunnan exhibit an eastward decrease in zircon εHf(t) and whole-rock εNd(t) values. By integrating these findings with the Hf isotopic mapping results, we suggest spatial heterogeneity in lower crustal composition in western Yunnan. The lower crust in the western Yangtze block comprises Neoproterozoic arc roots, while the lower crust of the Simao block represents a superposition of Neoproterozoic and Permian–Triassic arc roots. Based on the abrupt changes in angle and depth of the eastward-subducting Indian slab, along with the spatial characteristics of the Eocene–Oligocene magmatism, we propose that east–west-trending tearing of the subducted Indian slab occurs along approximately 26° N beneath the eastern Tibetan Plateau.

Spicing up nutrition: investigation of trace elements in some spices locally sold in two markets in Kisumu-Kenya.

Spices are integral to Kenyan cuisine, adding depth of flavour and aroma to dishes. Information on the levels of macro- and micronutrients in these spices is scarce, as they are sold locally in Kisumu City, Kenya; however, these species have medicinal value. The study reports the trace elements composition of eight selected spices (black pepper, cloves, ginger, cardamom, turmeric, cumin, red chillies, and garlic) sold in two open-air markets in Kisumu City. The trace elemental compositions for Zn, Ca, Fe, S, K, Na, P, Mg, Mn, B, Co, Li, Cu, Pb, and Cd were analysed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Ginger had the highest mean concentrations of most essential elements, K (5767.86 ± 43.44mg/kg), Mg (4615.36 ± 76.27mg/kg), B (132.08 ± 0.66mg/kg), Li (33.52 ± 0.84mg/kg), Mn (365.29 ± 2.22mg/kg), and Zn (70.44 ± 0.85mg/kg), followed by Ca (5290.44 ± 147.34mg/kg), Na (1361.88 ± 41.01mg/kg), P (3954.25 ± 122.68mg/kg), and S (4031.88 ± 106.95mg/kg), while turmeric had the lowest. The concentrations of macro-elements in spices from the Kibuye market were slightly higher than those from the Jubilee market; however, these differences were not statistically significant (p < 0.05). Concentrations of Pb and Cd heavy metals were detected and reported for all spices in the two markets, although the levels were below the WHO standard; hence, the spices are safe for use as supplements for essential trace elements in addition to their medicinal uses.