Compositional Gap Research Articles

Mediterranean Diet: its Nutritional Composition and Health Benefits in Chronic Disease Prevention

The Mediterranean diet (MD), as a scientifically proven healthy eating pattern, originated in the Mediterranean region and is gradually respected globally. In recent years, a large number of studies have confirmed its remarkable effect in the prevention and management of chronic diseases. However, there is still a certain research gap in the specific nutritional composition of the MD and its comprehensive understanding of health. Additionally, the widespread adoption of the MD faces challenges, including cultural differences and the adaptation of dietary habits. This article reviews the analysis of the major food groups and nutrients in the MD, exploring its health benefits in cardiovascular disease (CVD) prevention, management of type 2 diabetes and obesity, as well as cancer prevention. Through comprehensive existing research, this article reveals the scientific evidence of the MD to benefit health. The results of the research provide a scientific basis for promoting the MD, and provide direction for further studying the mechanism of the MD prevention disease in the future.

Unplugged: Navigating The Gaps In Body Composition, Nutrition, Sleep, And Gameplay Among Collegiate E-sports Athletes

Unplugged: Navigating The Gaps In Body Composition, Nutrition, Sleep, And Gameplay Among Collegiate E-sports Athletes

From super-Earths to sub-Neptunes: Observational constraints and connections to theoretical models

The growing number of well-characterized exoplanets smaller than Neptune enables us to conduct more detailed population studies. We have updated the PlanetS catalog of transiting planets with precise and robust mass and radius measurements and use this comprehensive catalog to explore mass-radius (M–R) diagrams. On the one hand, we propose new M–R relationships to separate exoplanets into three populations: rocky planets, volatile-rich planets, and giant planets. On the other hand, we explore the transition in radius and density between super-Earths and sub-Neptunes around M-dwarfs and compare them with those orbiting K- and FG-dwarfs. Using Kernel density estimation method with a re-sampling technique, we estimated the normalized density and radius distributions, revealing connections between observations and theories on composition, internal structure, formation, and evolution of these exo-planets orbiting different spectral types. First, the substantial 30% increase in the number of well-characterized exoplanets orbiting M-dwarfs compared with previous studies shows us that there is no clear gap in either composition or radius between super-Earths and sub-Neptunes. The “water-worlds” around M-dwarfs cannot correspond to a distinct population, their bulk density and equilibrium temperature can be interpreted by several different internal structures and compositions. The continuity in the fraction of volatiles in these planets suggests a formation scenario involving planetesimal or hybrid pebble-planetesimal accretion. Moreover, we find that the transition between super-Earths and sub-Neptunes appears to happen at different masses (and radii) depending on the spectral type of the star. The maximum mass of super-Earths seems to be close to 10 M⊕ for all spectral types, but the minimum mass of sub-Neptunes increases with the star’s mass, and is around 1.9 M⊕, 3.4 M⊕, and 4.3 M⊕, for M-dwarfs, K-dwarfs, and FG-dwarfs, respectively. The precise value of this minimum mass may be affected by observational bias, but the trend appears to be reliable. This effect, attributed to planet migration, also contributes to the fading of the radius valley for M-planets compared to FGK-planets. While sub-Neptunes are less common around M-dwarfs, smaller ones (1.8 Re < Rp < 2.8 R⊕) exhibit lower density than their equivalents around FGK-dwarfs. Nonetheless, the sample of well-characterized small exoplanets remains limited, and each new discovery has the potential to reshape our understanding and interpretations of this population in the context of internal structure, composition, formation, and evolution models. Broader consensus is also needed for internal structure models and atmospheric compositions to enhance density interpretation and observable predictions for the atmospheres of these exoplanets.

Pre-eruptive magmatic processes at Taranaki volcano from an amphibole perspective

Amphibole phenocrysts in post-1 ka lava domes deposits of Taranaki volcano, an andesite arc volcano in New Zealand, provide an opportunity to explore late-stage changes in melt composition and volatiles in the run up to eruption. Amphibole is a subordinate phase (0–7% of modal phenocrysts) and the phenocrysts display three types of growth history. Type 1 are large compositionally and texturally uniform phenocrysts that have low MgO (<13 wt%) and high K2O (∼1–1.4 wt%) contents. In contrast, Type 2 have similar cores but have been partially resorbed and overgrown by a mafic rim distinguished by high MgO (up to 15 wt%) and low K2O (<1.0 wt%) contents. Type 3 are the least common, and have either normal zoned or concentrically zoned interiors with respect to MgO and FeO. Overall, elemental substitutions and zonation patterns are related to periods of resorption and regrowth that are best explained by changes in melt composition. Based on calculated equilibrium melt compositions, the amphibole crystallisation is consistent with an incrementally grown andesitic to dacitic (SiO2 58–67 wt%) crystal mush that was periodically recharged with more mafic magma (SiO2 ∼ 55 wt%). The melts span a compositional gap (SiO2 ∼ 60–65 wt%) that is not represented in eruption products from the last 8 ka. Such melts were likely brief stages during ongoing fractional crystallisation and magma mixing. Each recharge event disrupted an evolving system and mixed crystals from different parts of it. This concept supports triggering of eruptions by recharge of mafic melts, as also inferred from plagioclase zonation for some eruptions from Taranaki. The outermost rims (0–5 μm) of many amphibole phenocrysts are enriched in fluorine (up to 1.9 wt%) and surrounded by a thick opacitic decomposition growths. We interpret this as the result of slow magmatic ascent and extensive crystallisation that produced a late-stage halogen-rich interstitial melt. This likely extended the conditions for amphibole stability to lower pressure. If F enrichment was accompanied by comparable enrichments in other halogens that preferentially partition into an aqueous phase, then extensive degassing would have occurred during the dome extrusions.

Carbonatite Metasomatism in a Subvolcanic Setting: Breccia at the Badou Carbonatite in the North China Craton and Implications for Magmatic Evolution and Eruptive Style

Abstract The genesis and primary compositions of carbonatite melts are enigmatic owing to their reactivity and resulting contamination in the mantle and crust. This overprints earlier uncontaminated compositions and obscures their origins. The subvolcanic Badou carbonatite in the North China Craton is characterized by brecciated textures and comprises pristine clinopyroxene, mica, and apatite phenocrysts in a mixed, carbonate–silicate matrix. Here, we provide mineralogical, textural, and major and trace elemental results to reveal the mantle derivation of the Badou carbonatite melt, and its compositional modification during interaction with crustal materials. Clinopyroxene and apatite phenocrysts have initial Sr isotopes (0.70920–0.71037) similar to brecciated calcite (0.71028–0.71159) and the whole rock (0.70953–0.71061), indicating a common source. Rare Mg-rich clinopyroxene and mica contain high Cr and Ni contents, recording direct mantle derivation without immiscibility from silicate melts. Abundant feldspars and aegirine, occurring as both phenocrysts and fine-grained matrix, formed an antiskarn at relatively low temperatures indicating extensive silica contamination upon crustal emplacement. Silica contamination is further indicated by britholite-rich apatite rims and relict quartz cores in clinopyroxene. Zircon xenocrysts were partly assimilated, indicated by Zr and Hf enrichment in late-stage silicates, and partly underwent decomposition to baddeleyite in a decreasing silica activity environment. The assimilation process consumed the carbonate melt, forming refractory silicate minerals and CO2 vapor, leading to near-surface gas overpressure with a decrease in magma viscosity. This elevates the potential for explosive activity, which, in turn, provides a positive feedback mechanism for silica assimilation. The complex evolution of the carbonatite melt in the crust might be responsible for the compositional gap between the natural rocks and experimental outcomes, and results in different eruption styles.

Geochemical and petrological diversity of a transcrustal magmatic system driven by mushy magma mixing: Insights from the Triassic dike swarms in East Kunlun orogen, northern Tibetan Plateau

Geochemical and petrological diversity within transcrustal magmatic systems usually reflects the magma properties and magmatic processes and thus is critical to understanding the origin of magmatic complexes and the evolution of continental crust. Herein, we present an integrated study on the petrology, mineralogy, geochronology, geochemistry, and Sr-Nd-Hf isotopes of Triassic mafic-felsic dikes in the East Kunlun orogenic belt, northern Tibetan Plateau, to elucidate the nature and evolution of the transcrustal magmatic system. The studied dikes intruding into the granodiorite pluton (ca. 235−233 Ma) comprise coeval ca. 220−218 Ma gabbroic diorite porphyry, diorite porphyry, granodiorite porphyry, and alkali-feldspar granite, resembling composite dike swarms. The macrocrysts in these dikes show various zoning patterns, indicating episodic magma recharge and crystal resorption. The compositional gap between the intermediate-mafic dikes (SiO2 = 52.9−67.8 wt%) and the granitic dikes (SiO2 &amp;gt;75 wt%), as well as their homogeneous whole-rock Sr-Nd isotopes, with (87Sr/86Sr)i = 0.708387−0.710995 and εNd(t) = −5.83 to −4.34, but variable zircon Lu-Hf isotopes, i.e., εHf(t) = −7.67 to −0.36, demonstrates that magma mixing rather than cogenetic fractional crystallization accounts for their origin. In combination with thermobarometric insights, these results suggest that the mafic and felsic parental magmas originating from an enriched lithospheric mantle and ancient continental crust, respectively, were ultimately emplaced and stagnated at varying crustal depths (∼22−30 km and 8−17 km). Subsequently, the felsic magma mush was replenished and rejuvenated by the underplated mafic magma, leading to varying degrees of crystal-melt and/or melt-melt mixing. This mush-facilitated crust-mantle magma mixing is an important mechanism accounting for the compositional diversity of the transcrustal magmatic system.

Primary study on frass fertilizers from mass-reared insects: Species variation, heat treatment effects, and implications for soil application at laboratory scale

Insect farming has gained popularity as a resource-efficient and eco-friendly method for managing organic wastes by converting them into high-quality protein, fat, and frass. Insect frass is a powerful organic fertilizer that enriches the soil with essential plant nutrients and enhances plant defense mechanisms through chitin stimulation. Given the importance of frass commercialization for many insect farmers and the use of increasingly diverse organic wastes as insect feedstocks, there is a need for legal guidelines to enable clean production practices. The recent introduction of a legal definition for frass and heat treatment requirements by the EU commission marks a significant step towards standardizing its quality; however, little is known about the processes shaping its nutritional profiles and contributing to its maturation. Our study addresses key knowledge gaps in frass composition and production practices. Here, we analyzed the physicochemical, plant-nutritional, and microbiological properties of black soldier fly, yellow mealworm, and Jamaican field cricket frass from mass-rearing operations and assessed the impact of hygienizing heat treatment on fertilizer properties and frass microbiota. The results showed that frass properties varied significantly across insect species, revealing concentrations of plant-available nutrients as high as 7000 μg NH4+-N, 150 μg NO2–NO3--N, and 20 mg available P per g of total solids. Heat treatment reduced microbial activity, biomass, and viable counts of pathogenic Escherichia coli and Salmonella spp. In terms of frass microbiome composition, alpha diversity showed no significant differences between fresh and heat-treated frass samples; however, significant differences in microbial community composition were observed across the three insect species. Despite heat treatment, soil application of frass reactivated and boosted soil microbial activity, inducing up to a 25-fold increase in microbial respiration, suggesting no long-term detrimental effects on microorganisms. These findings not only enhance our understanding of insect frass as a nutrient-rich organic fertilizer but also have implications for regulatory frameworks, underscoring its promising potential for soil health and nutrient cycling. However, it is important to recognize the primary nature of this research, conducted at laboratory scale and over a short term. Future studies should aim to validate these findings in agricultural settings and explore additional factors influencing frass properties and its (long-term) interaction with soil ecosystems.

Petrology and Geochemistry of Highly Differentiated Tholeiitic Magmas: Granophyres in the Messejana–Plasencia Great Dyke (Central Iberia)

The Messejana–Plasencia great dyke (MPGD) is a Late Triassic tholeiitic gabbro intrusion related to the Central Atlantic Magmatic Province. Its large outcrop extent (~530 km), combined with its prolongation below the Duero basin (additional 100 km), makes it one of the world’s largest dykes known. We have studied felsic granophyric bodies appearing in its northernmost segment at different scales, from mm-sized (interstitial micrographic pockets) to felsic dykes of up to 10 m thick and 1.5 km long, intruding within the gabbros. Significant differences exist in the mineral and whole-rock composition of gabbros and granophyres, including the Sr–Nd isotopic ratios. The chemical variation in the gabbros is coherent with fractionation of olivine, clinopyroxene and plagioclase at depth. However, the presence of a compositional gap between gabbros and granophyres (absence of intermediate compositions) and the formation of these late-stage intergranular felsic melts within the gabbro mesostasis suggest that they could be derived by liquid immiscibility. The Sr–Nd isotopic heterogeneity in the MPGD gabbros and the presence of zircons with Variscan ages (~286 Ma), inherited from granulitic rocks, indicate that the mafic magmas experienced some degree of lower crust assimilation during fractionation close to the Moho depth. On the contrary, the scarce xenocrystic Variscan zircon crystals found in a granophyric dyke within the MPGD gabbro display similar textures and ages (~299 Ma) to those of the country rock granites and point to contamination at a different crustal level.

Mn–Fe-rich genthelvite from pegmatites associated with the Madeira Sn–Nb–Ta deposit, Pitinga, Brazil: new constraints on the magmatic-hydrothermal transition in the albite-enriched granite system

AbstractGenthelvite from pegmatite veins hosted by the albite-enriched granite (ca.1.8 Ga) corresponding to the Sn–Nb–Ta (F, REE, Li, Zr, U, Th) Madeira deposit, Amazonas, Brazil was studied. Genthelvite, the exclusive Be-bearing mineral within the deposit, occurs as massive crystals of up to 4.7 cm in size. Compositions are homogeneous within individual crystals, although there is moderate variation in the overall composition reflecting relatively limited substitutions within the helvine–genthelvite–danalite solid-solution series, with relatively high Zn contents (36.96 to 49.45 wt.% ZnO), lower Mn contents (0.61 to 3.03 wt.% MnO), and variable Fe contents (2.10 to 10.94 wt.% FeO), completing an existing compositional gap in this system. Genthelvite formed in an alkaline and subaluminous environment, under stable conditions within the late-evolved fluids, at relatively high temperature (&gt;400°C), in a reducing environment. The extremely high concentration of fluorine in the magma and the crystallisation of magmatic galena resulted in an effective reduction of H2S fugacity. This resulted in the stabilisation of genthelvite during the transition from the late magmatic to early hydrothermal stages of the albite-enriched granite evolution. The variability in Fe content within genthelvite is associated primarily with localised variations in the mineral assemblage (e.g. the presence of riebeckite and polylithionite). Genthelvite was altered by low-temperature aqueous fluids rich in F which resulted in the incorporation of Fe, Mn, Mg, Pb, Ba, Na, K, U and REE into the Zn2+ structural site and the allocation of excess Si, Al, Ti and P in the IVSi and IVBe structural sites. The substantial content of U and REE substituting for Zn, together with Si substituting for Be, is charge balanced by the presence of vacancies at the A site.

The role of magmatic versus metasomatic processes in Ta-Nb mineralization at the Jiabusi Deposit, Inner Mongolia: Evidence from textural and chemical features of rare metal minerals and mica

The exact role magmatic versus metasomatic processes play in Ta-Nb mineralization is a question that has been debatable for several decades. The Jiabusi deposit is chosen to address this question, for its ample endowments of a variety of Ta-Nb oxides and mica in the various rock types that could provide insights into the whole evolutional history of ore-forming processes during magmatic-hydrothermal evolution. Textural and chemical evidence suggests that Fe-mica in the Fe-mica granite and pegmatitic portion is magmatic, indicating that the co-precipitated columbite-group minerals (CGM) and pyrochlore-supergroup minerals (PSM) are also magmatic. In the lepidolite granite and aplite, on the other hand, two stages of mineralization occured, represented by unzoned CGM that are in equilibrium with lepidolite, snowball quartz, and fluorite that all have a metasomatic origin and subsequent CGM/PSM overgrowths that co-precipitated with metasomatic Cs-lepidolite and saccharoidal albite. These CGM overgrowths have 1–2 time(s) higher Ta/(Nb + Ta) values than the preceded CGM, generating a clear compositional gap between them. Both stages of CGM and CGM/PSM precipitated from a hydrosilicate liquid (HSL), the partial migration of which results in the disequilibrium textures observed. The lepidolite granite is largely a metasomatic rock, the protolith of which has been obscured by intense metasomatism governed by the HSL. This HSL, however, is mainly constrained to the lepidolite granite but a few migrated into the Fe-mica granite. This is the main reason for the different mineralizing styles and intensities between the two rock types.

County Readiness for eTourism Using Systematic Gap Analysis: The Case of Jordan

The primary focus of this study is to establish a mechanism for assessing a country readiness for eTourism using two paradigms: systematic review and gap analysis. This assessment will be conducted by applying eTourism technology aspects as the main detriments of eTourism and behavioral aspects as moderating factors to generate a three-level gap index. The systematic review for determining gap analysis will be based on a framework developed in the literature of the eTourism Technology Acceptance Model (ETAM). This study, based on ETAM, develops its own framework for the systematic review. A comparative study was performed on two dimensions. The first dimension involves the examination of technology-related factors, encompassing security, accessibility of mobile applications, support for mobile payments, user interface design, and quality. To improve understanding of how tourists assess the four technological aspects, the second dimension included two moderating factors: attitude and trust. Based on the systematic review, this paper demonstrates a methodology for calculating individualized gaps for the six factors, as well as compounded gap indexes for the two dimensions and the total composite gap index (CGI) for all six factors through the utilization of an Excel spreadsheet. Based on the overall assessment, as the authors deduced from the discussions, Jordan's readiness for eTourism still needs further improvements to its eTourism factors. Future investigations will involve the implementation of a framework, such as Expert Choice, to emulate the methods utilized in this research. In addition, the outcome of this endeavor should suggest potential avenues for continuous improvement and diversification of eTourism research.

Mineral Chemistry of Pyrochlore Supergroup Minerals as Records of Nb Mineralization Processes in NYF-Type Pegmatites: A Case Study of the Emeishan Large Igneous Province, SW China

Alkaline igneous rocks have become a potentially important source of Nb, except for the carbonatites. The metallogenetic mechanism of Nb during the magmatic-hydrothermal evolution of alkaline rocks remains ambiguous. From the perspective of Nb minerals, the mineral chemistry of pyrochlore supergroup minerals provides the mineralogical evidence for indicating the respective contributions of magma and hydrothermal fluids to Nb mineralization. In the Miyi County of the Panzhihua-Xichang (Pan-Xi) area, the central zone of the Permian Emeishan large igneous province (ELIP) in SW China, hundreds of Nb-Y-F mineralized pegmatites (NYF-type) are exposed. This study conducted in situ mineral chemistry analyses on four types of pyrochlores to elucidate the Nb mineralization process. Both Pcl-I and Pcl-II exhibit well-developed oscillatory zoning (OZ), representing magmatic pyrochlore formed through disequilibrium crystallization in an oscillatory environment. Pcl-III, with a homogeneous and less variable composition, is also considered of magmatic origin due to its coherent chemical evolution with Pcl-II. Pcl-IV is considered of hydrothermal origin based on its irregular zoning texture, extremely high Na2O contents, and compositional gap compared with magmatic types. The decrease in TiO2 contents, coupled with the increase in Na2O, F, and Nb2O5 contents from Pcl-I to Pcl-III and from the core to the rim of zoned Pcl-II, indicates that fractional crystallization facilitates the crystallization of albite and the enrichment of volatiles, as well as the precipitation of Nb from the early to late stages. During the magmatic-hydrothermal transition stage, the reductive, Na- and F-enriched fluid transports Nb more effectively, leading to further Nb enrichment in pyrochlore. Consequently, there are two-stage Nb mineralization processes associated with the magmatic-hydrothermal evolution in the Miyi pegmatite, with the primary magmatic ore assemblages being the dominant Nb mineralization, which may be a general model for the mineralization of NYF-type pegmatites.

Artistic Signature's Aesthetic Consistency and Differentiation in Arabic Calligraphy

The artistic signature of calligraphers has been regarded as a significant aspect of Arabic calligraphy since its inception. As the art form evolved and acquired an aesthetic dimension, the artistic signature became an integral part of this dimension. The calligrapher failed to include his name on the frames, a practice that has become customary among calligraphers nowadays. This tradition allowed to trace the evolution of Arabic calligraphy and identify certain gaps in the calligraphy composition. Additionally, the inclusion of calligrapher's name contributes to the achievement of visual balance within the calligraphy composition, signifying consistency or formal separation. The current study concentrated to investigate the aesthetics of artistic signature in Arabic calligraphy, comprising of four parts. These parts include the research problem, its significance, objectives, area, and the definition of key terminologies. The current study analyzed a total of 25 samples, out of which 5 were selected for further analysis. The researchers appointed a descriptive approach to examine the sample models thereafter, the implementation of artistic signatures varied across the models, with the utilization of calligraphy,(Al-Ijaza, Kufi, Ta'liq, Diwāni, and Raq’a). Alterations in the structure and measurement of certain signature letters facilitated the creation of shorthand, which reduced the spaces within the signature structure and achieved formal closure. Additionally, the placement of signatures was distributed among different locations.

The solid solution in the system NaMgAl(SO4)3–KMgAl(SO4)3

We synthesized six samples in the compositional field NaMgAl(SO4)3–KMgAl(SO4)3 in 20 mol% increments from pure Na to pure K compounds. We investigated them by Powder X-Ray diffraction, 23Na, and 27Al Nuclear Magnetic Resonance spectroscopy. The results confirm NaMgAl(SO4)3 as a unique phase identical to a presumed new mineral found in the fumaroles of Eldfell and Hekla volcanoes in Iceland. It tolerates less than 10 mol% K substitution for Na. There exists a compositional gap to approximately Na0.65K0.35MgAl(SO4)3 from where a solid solution extends to KMgAl(SO4)3. The mineral koryakite [NaKMg2Al2(SO4)6] is a member of the latter solid solution series. The crystal structures of all (Na,K)MgAl(SO4)3 phases are akin to NASICON (NA Super Ionic CONductor). NaMgAl(SO4)3 has R3¯c\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R\\overline{3}c$$\\end{document} symmetry and a disordered distribution of Mg and Al among the octahedral sites with only one unique site for the alkali atom. The members of the solid solution have R3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R\\overline{3}$$\\end{document} symmetry with ordered Mg–Al distribution and two unique alkali sites with different preferences for Na and K. In the crystal structure, the coordination of Na and/or K is trigonal antiprismatic, and these share bases with two octahedral Mg (Na) or Al (K) coordinations. These polyhedra are arranged in columns parallel to [001] and interconnected by SO4 tetrahedral groups. The alkali atoms from a column lie in the same (001) layers as the octahedrally coordinated atoms from the three neighboring rows. On the same level, parallel to (001), there are gaps in the other three neighboring columns forming channels containing Na+ or K+ ions.

Investigating the Influence of Al Contents on Microstructure and Mechanical Properties of Ni3Al Superalloy Fabricated by Twin Wire‐Based Direct Arc Energy Deposition

In situ synthesis of Ni3Al by simultaneously feeding both Ni and Al wires into the molten pool is a common wire‐based additive manufacturing technology for Ni3Al superalloys. However, Ni3Al superalloys within a composition gap still have not yet been synthesized. The optimal composition range has also not been investigated yet. Herein, Ni3Al superalloys with Al equivalents between 17 and 25 at.% are fabricated by twin wire‐based direct arc energy deposition by adjusting the relative feeding speed. Microstructural analysis shows that the solidification products generate no γ′ precipitation when Al content is 17 at.%. Al promotes the formation of γ′ phase, as the Al content increases, the deposited Ni3Al superalloys with 20–25 at.% Al consist of dendritic γ + γ′ dual phase and interdendritic γ′ single phase. The proportion of γ + γ′ dual phase gradually increases with decreasing Al contents, whereas the tensile strength and elongation gradually increase. The Ni3Al superalloys (20 at.% Al) with the most γ + γ′ dual phase exhibit the highest tensile strength and elongation (939 MPa and 25.7%, respectively). Fracture analysis shows that the dislocation decomposition and stacking fault shearing mechanisms allow dislocations to continuously cut through γ′ precipitations to maintain deformation, which is responsible for high tensile strength and ductility.

Petrogenesis and implications for tin mineralization of the Beidashan granitic pluton, southern Great Xing'an Range, NE China: Constraints from whole-rock and accessory mineral geochemistry

The Beidashan pluton, consisting of quartz monzonite in the northeast and biotite granite in the southwest, is a representative granitic intrusion in the southern Great Xing'an Range. To investigate its petrogenesis and relationship with tin mineralization, whole-rock and accessory minerals (zircon and apatite) geochemical analyses were carried out. The quartz monzonite mainly belongs to high-K calc-alkaline strongly peraluminous granite, and the biotite granite is high-K calc-alkaline weakly peraluminous granite. Zircon U-Pb dating indicates a younger age for the biotite granite (138 Ma) than the quartz monzonite (140 Ma). The zircon Hf and apatite Nd isotopic compositions of the quartz monzonite (εHf(t) = 5.2 to 9.1 and εNd(t) = −1.1 to 1.3) and those of the biotite granite (εHf(t) = 5.6 to 8.0 and εNd(t) = −0.9 to 1.0) are indistinguishable, implying that they were derived from the same sources. Modeling results using apatite Nd isotope data show that they were from a mixing source of the Xilinhot Group and mantle-derived basaltic melt. Whole-rock and apatite trace elements reveal that the granitic magma mainly experienced fractional crystallization of amphibole, biotite, plagioclase, K-feldspar, apatite, and monazite from the quartz monzonite to the biotite granite. Mineralogical, whole-rock geochemical, and apatite trace element data indicate that the Beidashan pluton has an I-type granite affinity. A crystal mush model was proposed accounting for the composition gap between these two granites (e.g., SiO2, Al2O3, and Ba), in which the biotite granite represents the highly fractionated interstitial melt extracted from the crystal mush system whereas the quartz monzonite is the residual crystal mush consisting of the cumulate crystals and trapped interstitial melt. The melt was extracted when the crystallinity of the crystal mush reached about 33–37%, and the residual crystal mush trapped about 38–46% interstitial melt. Both Ce anomalies in zircon and Eu anomalies in apatite imply reducing conditions. The calculated values of oxygen fugacity for the Beidashan pluton range from −19.3 to −15.7, and most of them are lower than the fayalite-magnetite-quartz (FMQ) oxygen buffer. Apatite in the Beidashan pluton has high F (2.35–3.61%) and low Cl (0–0.41%) concentrations, which are similar to those of Sn-W deposits worldwide. The Sn contents of apatite increase from the quartz monzonite (mean 0.30 ppm) to the biotite granite (mean 1.09 ppm), suggesting that magma evolution is important for the enrichment of Sn in the melt.

Estimating the silica content and loss-on-ignition in the North American Soil Geochemical Landscapes datasets: a recursive inversion approach

A novel method of estimating the silica (SiO 2 ) and loss-on-ignition (LOI) concentrations for the North American Soil Geochemical Landscapes (NASGL) project datasets is proposed. Combining the precision of the geochemical determinations with the completeness of the mineralogical NASGL data, we suggest a ‘reverse normative’ or inversion approach to first calculate the minimum SiO 2 , water (H 2 O) and carbon dioxide (CO 2 ) concentrations in weight percent (wt%) in these samples. These can be used in a first step to compute minimum and maximum estimates for SiO 2 . In a recursive step, a ‘consensus’ SiO 2 is then established as the average between the two aforementioned SiO 2 estimates, trimmed as necessary to yield a total composition (major oxides converted from reported Al, Ca, Fe, K, Mg, Mn, Na, P, S and Ti elemental concentrations + ‘consensus’ SiO 2 + reported trace element concentrations converted to wt% + ‘normative’ H 2 O + ‘normative’ CO 2 ) of no more than 100 wt%. Any remaining compositional gap between 100 wt% and this sum is considered ‘other’ LOI and likely includes H 2 O and CO 2 from the reported ‘amorphous’ phase (of unknown geochemical or mineralogical composition) as well as other volatile components present in soil. We validate the technique against a separate dataset from Australia where geochemical (including all major oxides) and mineralogical data exist on the same samples. The correlation between predicted and observed SiO 2 is linear, strong ( R 2 = 0.91) and homoscedastic. We also compare the estimated NASGL SiO 2 concentrations with a sparser, publicly available continental-scale survey over the conterminous USA, the ‘Shacklette and Boerngen’ dataset. This comparison shows the new data to be a reasonable representation of SiO 2 values measured on the ground over the conterminous USA. We recommend the approach of combining geochemical and mineralogical information to estimate missing SiO 2 and LOI by the recursive inversion approach in datasets elsewhere, with the caveat to always validate results.

Structure and thermoelectric properties of half-Heusler-like TiFeCuxSb alloys

Previous research on the ternary Ti-Fe-Sb system has revealed that stoichiometric TiFeSb cannot exist as a stable compound, whereas a single-phase TiFe1.33Sb alloy with the half-Heusler-like structure has been synthesized by adding excessive Fe. In this work, we report that TiFeSb can also be stabilized by filling additional Cu to the vacant 4d site of the half-Heusler lattice. Our experiments indicate that the TiFeCuxSb (x = 0–0.25) samples exhibit a p-type conduction with extremely high carrier concentration ((0.5 –2.5) × 1022 cm−3)), while these samples attain very large Seebeck coefficients, over 100 μV/K in the whole measured temperature range for the samples with x = 0.15–0.25. In addition, a logarithmic divergence of the temperature-dependent specific heat capacity (CP/T) is observed at low temperatures, implying the strange-metal behavior of TiFeCuxSb samples. The partial filling of the vacant 4d site results in significantly reduced lattice thermal conductivity, leading to the low total thermal conductivity of 2.8 W·m−1·K−1 at 823 K for the TiFeCu0.20Sb sample. Consequently, a dimensionless figure of merit zT of 0.54 at 923 K is realized for TiFeCu0.20Sb, demonstrating that promising thermoelectric materials with intriguing physical properties can be discovered in the composition gap of half- and full-Heusler alloys.

New evidence for the Ontong Java Nui hypothesis

The formation of the Ontong Java Nui super oceanic plateau (OJN), which is based on the model that the submarine Ontong Java Plateau (OJP), Manihiki Plateau (MP), and Hikurangi Plateau (HP) were once its contiguous fragments, could have been the largest globally consequential volcanic event in Earth’s history. This OJN hypothesis has been debated given the paucity of evidence, for example, the differences in crustal thickness, the compositional gap between MP and OJP basalts and the apparent older age of both plateaus relative to HP remain unresolved. Here we investigate the geochemical and 40Ar-39Ar ages of dredged rocks recovered from the OJP’s eastern margin. Volcanic rocks having compositions that match the low-Ti MP basalts are reported for the first time on the OJP and new ~ 96–116 Ma and 67–68 Ma 40Ar-39Ar age data bridge the temporal gap between OJP and HP. These results provide new evidence for the Ontong Java Nui hypothesis and a framework for an integrated tectonomagmatic evolution of the OJP, MP, and HP. The isotopic data imply four mantle components in the source of OJN that are also expressed in present-day Pacific hotspots sources, indicating origin from (and longevity of) the Pacific Large Low Shear-wave Velocity Province.

Occurrence dataset of birds in the Xinjizhou National Wetland Park, Nanjing, China.

Xinjizhou National Wetland Park is located in Jiangning District, Nanjing, Jiangsu, China. With diverse wetland landscape types, Xinjizhou National Wetland Park maintains high biodiversity all year around. Meanwhile, as an important hub on the East Asian-Australasian Flyway, Xinjizhou National Wetland Park also occupies a core ecological position in the middle and lower reaches of the Yangtze River in Jiangsu Province. Therefore, carrying out systematic bird surveys and consequently understanding the distribution of birds and the seasonal variation of their communities can provide important insights for conservation. We conducted a one-year bird survey in the Xinjizhou National Wetland Park from 2021 to 2022 and provided occurrence datasets, including detailed species and geographic information.This dataset fills the knowledge gap in avian community composition for the Wetland Park and more importantly provides a basis to assess the conservation effectiveness of conservation measures taken in the Wetland Park. This occurrence dataset is the first public record of birds in Xinjizhou National Wetland Park. All data have been published on GBIF.