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The SC-3 speleothem from Szczelina Chochołowska Cave, located in the Tatra Mountains, was studied in detail. U-series dating and age–depth modeling allowed us to constrain the period of speleothem growth to between approximately 330 and 200 ka, that is, during Marine Isotope Stages (MIS) 9–7. The complementary use of stable isotope analyses, petrographic studies, and trace element analyses allowed the identification of warm and wet climatic conditions that were favorable for speleothem growth during MIS 9e and MIS 9c. Unfavorable climatic periods included the cold glacial conditions of MIS 8 and the MIS 9/MIS 8 transition. The breaks in the growth of the SC-3 stalagmite were most likely connected with a reduction in precipitation in MIS 9a and extreme hydrologic events during MIS 8. Comparisons with other European records suggest that the climatic variability recorded in the speleothem from the Tatra Mountains is not only a record of local environmental conditions but can also be linked to European climatic patterns during both interglacial and glacial intervals. This makes our study the northernmost paleoclimatic record for the whole Carpathian range and one of the very few records from those periods worldwide.
An integrated approach involving Sr–Nd isotope, trace and rare earth element analyses tracks multiple sources of the Mesozoic sediments of the Kutch Basin at the western continental margin of India. High (87Sr/86Sr)t (ratio at time of deposition), negative εNd and high concentrations of large-ion lithophile elements (LILEs) indicate the upper continental source. Ratios of Nb/Ta and Zr/Hf suggest sedimentary and felsic igneous sources of sediments. The moderate to high concentration of La, Th and Sc, light rare earth elements (LREE-) enrichment, weak negative Eu anomalies and the relationship between εNd(0) and Th/Sc indicate the dominantly felsic composition of source rocks. However, low contents of Th, low values of (87Sr/86Sr)t and depleted mantle model age TDM < 1600 Ma indicate input from a younger mafic source. Increasing concentrations of Zr, Hf and Nd isotopes and a gradual increase in mean TDM from the older to the younger formations indicate erosional unroofing at the source terrain. The increasing (87Sr/86Sr)t through time relates to increased weathering of the source rock. The overwhelmingly southwesterly palaeocurrent direction of current-generated sedimentary structures, and the mean TDM ages trace suggest source areas of the Kutch Basin to Precambrian rocks in the north and NE of this basin. The TDM ages highlight the dominance of late Palaeoproterozoic source rocks. Nd isotope composition indicates that Proterozoic rocks of Marwar Supergroup and Erinpura Granite, in particular, served as main sediment contributors for the Mesozoic sediments in Kutch. We therefore conclude that the Mesozoic sediments in the Kutch Basin are predominantly of late Palaeoproterozoic age with lesser inputs from rocks of early Mesoproterozoic and early Palaeoproterozoic age.
Despite evidence for the effects of metals on neurodevelopment, the long-term effects on mental health remain unclear due to methodological limitations. Our objective was to determine the feasibility of studying metal exposure during critical neurodevelopmental periods and to explore the association between early-life metal exposure and adult schizophrenia.
We analyzed childhood-shed teeth from nine individuals with schizophrenia and five healthy controls. We investigated the association between exposure to lead (Pb2+), manganese (Mn2+), cadmium (Cd2+), copper (Cu2+), magnesium (Mg2+), and zinc (Zn2+), and schizophrenia, psychotic experiences, and intelligence quotient (IQ). We reconstructed the dose and timing of early-life metal exposures using laser ablation inductively coupled plasma mass spectrometry.
We found higher early-life Pb2+ exposure among patients with schizophrenia than controls. The differences in log Mn2+ and log Cu2+ changed relatively linearly over time to postnatal negative values. There was a positive correlation between early-life Pb2+ levels and psychotic experiences in adulthood. Moreover, we found a negative correlation between Pb2+ levels and adult IQ.
In our proof-of-concept study, using tooth-matrix biomarker that provides direct measurement of exposure in the fetus and newborn, we provide support for the role of metal exposure during critical neurodevelopmental periods in psychosis.
When readymade parenteral nutrition in multi-chamber bags is supplied without vitamins and minerals, these have to be added or given separately. Separate rapid infusion has logistical advantages but has been claimed to saturate tissue mechanisms, potentially increasing urine micronutrient losses. The present study compared urinary losses after fast (1 h) v. slow (10 h) trace elements infusion. The study enrolled thirty-nine consecutive patients who were starting parenteral nutrition postoperatively. One day’s dose of a complete intravenous micronutrient product was infused over 1 h and over 10 h, in random order, with a washout day after each infusion day. Urinary Zn, Mn, Se, Cr, Cu and Fe losses were measured by 24-h urine collection, recorded for each infusion day and subsequent washout day. For Zn, a dose of 100 μmol was given, and total urinary loss over the next 2 d was mean 40·6 (sd 23·8) μmol after the fast (1 h) infusion v. 33·4 (sd 25·4) μmol after the slow (10 h) infusion, that is, 7 % more of the 1-d dose was lost after fast infusion (P = 0·01). For Mn, after a dose of 1000 nmol, losses were 9·8 (sd 23·9) nmol after the fast infusion v. 22·1 (sd 47·2) nmol after the slow infusion, that is, 1 % more of the 1-d dose was lost after slow infusion (P = 0·04). There were no other significant differences: after 1 μmol Se, the losses were 1·5 (sd 0·6) μmol fast v. 1·3 (sd 0·5) μmol slow; after 200 nmol Cr, 257 (sd 92) μmol fast v. 246 (sd 107) nmol slow; after 8 μmol Cu, 1·6 (sd 1·4) μmol fast v. 1·5 (sd 1·3) μmol slow; and after 20 μmol Fe, 0·6 (sd 1·1) μmol fast v. 0·8 (sd 1·6) μmol slow (P > 0·05 for all). Overall, trace element retention appears to be minimally affected by infusion time.
Poultry meat is a valuable source of nutrients and the enrichment with health-promoting substances such as polyunsaturated fatty acids (n-3 PUFA) is an important factor for consumers’ choice. Camelina meal (Camelina sativa) is an animal feedstuff used to achieve this goal, but the administration of n-3 PUFA-enriched diets in broiler nutrition can accelerate the oxidative processes in meat leading to a decreased quality of final product. The aim of this study was to investigate the effect of the organic Cr as chromium picolinate (CrPic) on meat quality, fatty acid profile of fat and oxidative stability of meat from broilers fed supplemented dietary Camelina meal. An experiment was conducted on 240 Ross 308 broiler chicken aged 14 days which were assigned to 6 dietary treatments in a randomized complete block design with a 2 × 3 factorial arrangement. Within the treatment arrangement two concentrations of Camelina meal (0% and 3%) and three concentrations of Cr3+ (0, 200 and 400 μg/kg) were used. Dietary treatments were: (1) Control diet (C) containing a corn–soybean diet with no added Camelina meal or Cr3+; (2) a C diet containing an additional 200 μg/kg of Cr3+ as CrPic; (3) a C diet containing an additional 400 μg/kg of Cr3+ as CrPic; (4) a C diet containing an additional 3% Camelina meal; (5) diet 2 containing an additional 3% Camelina meal; (6) diet 3 containing an additional 3% Camelina meal. Chromium supplementation significantly (P<0.05) increased the CP concentrations and significantly (P<0.05) decreased the crude fat concentrations in breast samples. The Camelina meal groups presented higher values of unsaturated fatty acids, particularly n-3 fatty acids (P<0.05). In CrPic groups, increased retention of Zn and Fe (P < 0.05) was observed in breast samples, compared to control group, and thiobarbituric acid reactive substances values were significantly (P<0.05) smaller. Myoglobin fraction (metmyoglobin and oximyoglobin) concentrations differ significantly (P<0.05) from the control group, under the influence of Cr3+ supplements. This study found that broilers fed with CrPic supplements showed improved mineral composition and oxidative stability of breast meat, proving an effective protection of lipid molecules from oxidation in PUFA-enriched meat.
Sphalerite is the main source of In – a ‘critical’ metal widely used in high-tech electronics. In this mineral the concentration of In is commonly correlated directly with Cu content. Here we use X-ray absorption spectroscopy of synthetic compounds and natural crystals in order to investigate the substitution mechanisms in sphalerites where In is present, together with the group 11 metals. All the admixtures (Au, Cu, In) are distributed homogeneously within the sphalerite matrix, but their structural and chemical states are different. In all the samples investigated In3+ replaces Zn in the structure of sphalerite. The In ligand distance increases by 0.12 Å and 0.09–0.10 Å for the 1st and 2nd coordination shells, respectively, in comparison with pure sphalerite. The In–S distance in the 3rd coordination shell is close to the one of pure sphalerite. Gold in synthetic sphalerites is coordinated with sulfur (NS = 2.4–2.5, RAu–S = 2.35 ± 0.01 Å). Our data suggest that at high Au concentrations (0.03–0.5 wt.%) the Au2S clusters predominate, with a small admixture of the Au+ solid solution with an Au–S distance of 2.5 Å. Therefore, the homogeneous character of a trace-element distribution, which is commonly observed in natural sulfides, does not confirm formation of a solid solution. In contrast to Au, the presence of Cu+ with In exists only in the solid-solution state, where it is tetrahedrally coordinated with S atoms at a distance of 2.30 ± 0.03 Å. The distant coordination shells of Cu are disordered. These results demonstrate that the group 11 metals (Cu, Ag and Au) can exist in sphalerite in the metastable solid-solution state. The solid solution forms at high temperature via the charge compensation scheme 2Zn2+↔Me++Me3+. The final state of the trace elements at ambient temperature is governed by the difference in ionic radii with the main component (Zn), and concentration of admixtures.
The trace elements in quartz, Al and Ti, contain considerable information about mineral genesis, and determining their concentrations is of great importance in geology. Electron probe microanalysis has the advantages of non-destructive testing and high spatial resolution; however, it is a challenge to improve the accuracy and precision of trace element detection using this method. The important factors affecting accuracy include the fragility of quartz lattices at high beam currents and the methods used to determine the background. In this paper, the peaks of Al-Kα and Ti-Kα, and their backgrounds, were found to exhibit intensity variations at high beam currents and small beam diameters; therefore, it is necessary to select a large beam diameter (up to 20 µm) to avoid variations in intensity at high currents (500 nA). For background determination of Al, a multipoint background method is proposed to determine the background value, which greatly improves the accuracy of the results. For Ti, the choice of background measurement does not affect the result. In addition, it is verified that the background obtained from other quartz samples can be used as the background of an unknown quartz sample, which reduces the analysis time and minimizes sample damage.
A fine-grained, up to 3-m-thick tephra bed in southwestern Saskatchewan, herein named Duncairn tephra (Dt), is derived from an early Pleistocene eruption in the Jemez Mountains volcanic field of New Mexico, requiring a trajectory of northward tephra dispersal of ~1500 km. An unusually low CaO content in its glass shards denies a source in the closer Yellowstone and Heise volcanic fields, whereas a Pleistocene tephra bed (LSMt) in the La Sal Mountains of Utah has a very similar glass chemistry to that of the Dt, supporting a more southerly source. Comprehensive characterization of these two distal tephra beds along with samples collected near the Valles caldera in New Mexico, including grain size, mineral assemblage, major- and trace-element composition of glass and minerals, paleomagnetism, and fission-track dating, justify this correlation. Two glass populations each exist in the Dt and LSMt. The proximal correlative of Dt1 is the plinian Tsankawi Pumice and co-ignimbritic ash of the first ignimbrite (Qbt1g) of the 1.24 Ma Tshirege Member of the Bandelier Tuff. The correlative of Dt2 and LSMt is the co-ignimbritic ash of Qbt2. Mixing of Dt1 and Dt2 probably occurred during northward transport in a jet stream.
Micronutrients such as trace elements and vitamins are important as enzyme cofactors in the metabolism of all cells in the body and therefore key to determining nutritional status. The present systematic review examined the evidence of the impact of the systemic inflammatory response on plasma micronutrient status in acute (surgical) and chronic tissue injury. A literature review using targeted subject headings was carried out. Plasma C-reactive protein was used to classify minor (<10 mg/l), moderate (11–80 mg/l) and major (>80 mg/l) inflammation. The literature search produced 2344 publications and plasma vitamin D, zinc and carotenoids were most commonly studied and plasma vitamins K, B2 and B6 were least studied. In acute injury thirteen studies (all prospective) and in chronic injury twenty-four studies (largely retrospective) were included in the review. There was consistent evidence that most common measured micronutrients in the plasma (zinc, selenium, vitamins A, D, E, K, B2, B6, B12, C, lutein, lycopene, α- and β-carotene) were significantly lowered from minor to moderate to major inflammation. The results of the present systematic review indicate that most plasma micronutrients fall as part of the systemic inflammatory response irrespective of acute or chronic injury. Therefore, in the presence of a systemic inflammation, plasma micronutrient concentrations should be interpreted with caution. There are a number of methods applied to adjust plasma micronutrient concentrations to avoid misdiagnosis of deficiency. Alternatively, intracellular measurements appear to obviate the need for such plasma adjustment to assess micronutrient status.
Birds have evolved in direct contact with natural nanoparticles (NPs) that are identical to artificial trace-element NPs. This relationship, the high action potential and their ability to reduce environmental pollution make NPs a promising component of bird diets. However, from available published studies there is no unity in justifying the applied dosages of NPs and their calculations. NPs are used in the studies in various doses, for example: Cu 0.5-50 mg/kg, Ag 10-1000 mg/kg, Se 0.2-5 mg/kg, Cr 500-1500 ppb. Therefore, universal approaches and criteria of NP investigations are necessary for the establishment of their use in feed.
The mechanisms of action of the trace elements in artificial NPs in birds vary from the those of ionic forms of trace elements, which determine the differences in the productive effect. According to data from different authors, chickens receiving NPs in feed have higher chickens body weight by 13-24%. Such benefits have increased interest in sources of trace-element NPs significantly over the past two decades. The design of trace-element NPs has led to promising developments in the safe use of NPs for poultry nutrition, such as coating NPs with inert substances and adjusting their size. However, constraining circumstances determined by the difficulty of predicting the toxic properties of nanostructures exist, even though artificial trace-element NPs are a relatively safe class of nanostructures due to their production requirements, and metal NPs are already used in human food and medicine. The following review discusses the benefits and potential hazardous effects of NPs and the possibility of using them as feed supplements for poultry.
Micronutrients are indispensable for adequate metabolism, such as biochemical function and cell production. The production of blood cells is named haematopoiesis and this process is highly consuming due to the rapid turnover of the haematopoietic system and consequent demand for nutrients. It is well established that micronutrients are relevant to blood cell production, although some of the mechanisms of how micronutrients modulate haematopoiesis remain unknown. The aim of the present review is to summarise the effect of Fe, Mn, Ca, Mg, Na, K, Co, iodine, P, Se, Cu, Li and Zn on haematopoiesis. This review deals specifically with the physiological requirements of selected micronutrients to haematopoiesis, showing various studies related to the physiological requirements, deficiency or excess of these minerals on haematopoiesis. The literature selected includes studies in animal models and human subjects. In circumstances where these minerals have not been studied for a given condition, no information was used. All the selected minerals have an important role in haematopoiesis by influencing the quality and quantity of blood cell production. In addition, it is highly recommended that the established nutrition recommendations for these minerals be followed, because cases of excess or deficient mineral intake can affect the haematopoiesis process.
Low concentrations of elements in food can be measured with various techniques, mostly in small samples (mg). These techniques provide only reliable data when the element is distributed homogeneously in the material to be analysed either naturally or after a homogenisation procedure. When this is not the case or homogenisation fails, a technique should be applied that is able to measure in samples up to grams and even kilograms and regardless of the distribution of the element. An adaptation of neutron activation analysis (NAA), called large-sample NAA, has been developed and proven accurate and may be an attractive alternative in food research and mass balance studies. Like standard NAA, large-sample NAA can be used to measure both toxic and trace elements relevant for nutrition.
The efficiency of two low-cost, abundant and natural clay minerals, palygorskite and vermiculite, in terms of reducing the concentation of Cu2+ and Ni2+ ions was evaluated here. Natural clay minerals were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), BET specific surface area and pore-diameter analysis. Batch-type experiments were performed and various parameters, i.e. pH, clay amount, contact time and initial metal concentration, that affect adsorption processes were investigated. The adsorption of Cu2+ and Ni2+ ions is pH-dependent, while minor clay quantities were sufficient to achieve high removal efficiencies. Adsorption equilibrium occurred in 60 min and the adsorption kinetics were better described by pseudo-second-order kinetics. Experimental results were analysed by the Langmuir, Freundlich, Dubinin–Radushkevich (D–R), Temkin and Halsey isotherm equations. The release of exchangeable cations (i.e. Ca2+, Mg2+, Na+ and K+) was examined to verify an ion-exchange mechanism.
A study of the cathodoluminescence (CL) properties of imperial topaz from Ouro Preto region (Minas Gerais state, Brazil) and its relation with trace-element composition was conducted, using scanning electron microscope cathodoluminescence (SEM-CL), optical microscope cathodoluminescence (OM-CL), cathodoluminescence-spectrometry (CL-spectrometry), electron microprobe analysis (EMPA), laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) and Raman spectrometry. Each analytical technique allowed characterization of the imperial topaz fingerprint. SEM-CL panchromatic images show different crystal growth and resorption events in imperial topaz crystals. Colour CL images indicate only blue to violet emissions. The CL-spectra indicate a broad emission band with low intensity peak at ~417 nm and a broad emission band with high intensity and major peaks at 685, 698, 711 and 733 nm. The EMPA indicates high OH content, in which the OH/(OH + F) ratio ranges between 0.35–0.43 (0.72 ≤ OH ≤ 0.86 apfu). High Cu and Zn concentrations (LA-ICP-MS) were measured in the high luminescence areas of SEM-CL images, suggesting both elements as CL-activators in imperial topaz. Raman and CL-spectra indicate high Cr concentrations, corroborated by EMPA and LA-ICP-MS results. The high Cr caused strong luminescence intensities that enabled their superimposition over the OH stretching mode (~3650 cm–1) of topaz in all Raman spectra. Among trace elements, the concentrations of Ti, V, Cr, Mn, Fe, Cu, Zn, Ga and Ge provide the fingerprint of imperial topaz.
Concentration data are reported for 18 trace elements in chalcopyrite from a suite of 53 samples from 15 different ore deposits obtained by laser-ablation inductively-coupled plasma-mass spectrometry. Chalcopyrite is demonstrated to host a wide range of trace elements including Mn, Co, Zn, Ga, Se, Ag, Cd, In, Sn, Sb, Hg, Tl, Pb and Bi. The concentration of some of these elements can be high (hundreds to thousands of ppm) but most are typically tens to hundreds of ppm. The ability of chalcopyrite to host trace elements generally increases in the absence of other co-crystallizing sulfides. In deposits in which the sulfide assemblage recrystallized during syn-metamorphic deformation, the concentrations of Sn and Ga in chalcopyrite will generally increase in the presence of co-recrystallizing sphalerite and/or galena, suggesting that chalcopyrite is the preferred host at higher temperatures and/or pressures. Trace-element concentrations in chalcopyrite typically show little variation at the sample scale, yet there is potential for significant variation between samples from any individual deposit. The Zn:Cd ratio in chalcopyrite shows some evidence of a systematic variation across the dataset, which depends, at least in part, on temperature of crystallization. Under constant physiochemical conditions the Cd:Zn ratios in co-crystallizing chalcopyrite and sphalerite are typically approximately equal. Any distinct difference in the Cd:Zn ratios in the two minerals, and/or a non-constant Cd:Zn ratio in chalcopyrite, may be an indication of varying physiochemical conditions during crystallization.
Chalcopyrite is generally a poor host for most elements considered harmful or unwanted in the smelting of Cu, suggesting it is rarely a significant contributor to the overall content of such elements in copper concentrates. The exceptions are Se and Hg which may be sufficiently enriched in chalcopyrite to exceed statutory limits and thus incur monetary penalties from a smelter.
The bigfin reef squid Sepioteuthis lessoniana is a neritic species widely distributed in coastal waters of the Indo-Pacific region and is of interest to fisheries for its high commercial value. Squid samples were collected from Keelung (KL) and Penghu (PH), around northern Taiwan from October 2012 to September 2013. A total of 949 squid were examined, and 620 squid were aged using statoliths. The age range of the squid in KL (55–183 days) was similar to that in PH (77–186 days). The squid hatched almost year-round, except in January and December in KL. Two seasonal cohorts were identified: a spring cohort (hatched in March to May) and an autumn cohort (July to October). Concentrations of nine trace elements in statoliths were analysed using solution-based inductively coupled plasma mass spectrometry (ICP-MS). Significant differences in Fe/Ca, Cu/Ca and Sr/Ca were found between the two locations, while significant differences in concentration ratios of Sr/Ca and Ba/Ca were noted between the two seasonal cohorts. Results of a principal component analysis and cluster analysis varied in life-history traits between the two geographic stocks and in elemental concentrations between the two seasonal cohorts. Squid in KL and PH might undertake different migration routes, while seasonal variability in oceanographic conditions was apparent in the two locations.
The distribution of Au and associated trace elements in pyrite and
arsenopyrite from late Archean Hutti and Hira-Buddini orogenic gold
deposits, eastern Dharwar Craton, southern India was investigated by laser
ablation-inductively coupled plasma-mass spectrometry. X-ray element maps
acquired by electron probe microanalyser reveal oscillatory zoning of Co and
As indicating the crystallization of pyrite and arsenopyrite in an episodic
fluid flow regime in which fluid salinity fluctuated due to fault-valve
actions. The absence of any relationship between Au and As in pyrite obviate
the role of As in the incorporation of Au into pyrite, particularly here and
may be generally the case in orogenic gold deposits. On the other hand,
positive correlations of Au with Cu, Ag and Te suggest possible influence of
these chalcophile elements in the enhanced gold concentrationin sulfides.
Pb-Bi-Te-Au-Ag bearing micro-particles (<2 μm) are observed exclusively
in micro-fractures and pores in arsenopyrite. The absence of replacement
features and element gradient suggests direct precipitation of Pb, Bi, Te,
Au and Ag from a fluid that was unreactive towards arsenopyrite. An
intermittent fall in fluid pressure caused by the fault-valve action would
have resulted in the sporadic precipitation of Au, Pb, Ag, Bi and Te.
The chemical and mineralogical composition of rattlestones found near the main Dutch rivers has been studied by Mössbauer spectroscopy, INAA and XRD. Rattlestones are concretions of iron, formed in an environment of lateral iron accumulation, under the influence of periodical oxidation, around a fine core of ferruginous sediments, mainly clay and sand. The core has shrunk and detached itself from the mantle around it. 57Fe Mössbauer spectroscopy was applied to identify the iron oxides, among which goethite is predominant. The goethite crystallinity was investigated by measuring its magnetic properties and its crystallinity, which is poorest at the outer side of the stone. The latter is confirmed by the broadening of the different X-ray reflections. In addition, illite and vermiculite were identified by XRD; these clay minerals were found mainly in the core.
The elemental composition was determined by INAA. The iron content in the mantle is about 50% by weight and gradually decreases outwards, while the core contains 2–15% Fe by weight. Differences between rattlestones from the Middle Pleistocene East of the Meuse river and those from the Late Pleistocene North of it are the absence of lepidocrocite and a richer mineralogy in the former.
It is concluded that the rattlestones are formed around a fine clayey core. Groundwater supplied the iron and other (trace) elements for the genesis. It is unlikely that rattlestones are the result of oxidation of siderite.
Mica pegmatites from the Bihar Mica Belt contain three distinct generations of tourmaline. The major-element composition, substitution vectors and trajectories within each group are different, which indicates that the three types of tourmalines are not a part of one evolutionary series. Rather, the differences in their chemistries as well their mutual microtextural relations, can be best explained by growth of tourmaline from pegmatitic melts followed by episodic re-equilibration during discrete geological events. The euhedral, coarse-grained brown type I tourmaline cores have relatively high Ca, Mg (XMgc. 0.37) and Al with correlated variation in Sr, Sc, Ti, Zr, Y, Cr, Pb and Rare Earth elements (REEs). They are inferred to have crystallized from pegmatitic melts. Monazites included within these tourmalines give chemical ages of 1290−1242 Ma interpreted to date the crystallization of the pegmatitic tourmaline. The bluish type II and greyish type III tourmalines with low Ca and Mg contents (XMg = 0.16−0.27) and high Zn, Sn, Nb, Ta and Na, formed by pseudomorphic partial replacement of the pegmatitic tourmaline via fluid-mediated coupled dissolution–reprecipitation, are ascribed to a hydrothermal origin. The ages obtained from monazites included in these tourmalines indicate two alteration events at c. 1100 Ma and c. 950 Ma. The correlated variation of Ca, Mg and Fe and the trace elements Sr, Sn, Sc, Zn and REE within the tourmalines indicates that the trace-element concentrations of tourmaline are controlled not only by the fluid chemistry but also by coupled substitutions with major-element ions.
Gem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.