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Introduction: Sirjan 001 is an iron meteorite weighting ~12.9 kg that was found in March 2018 in Kerman province (Iran). Based on petrographic and bulk-rock elemental composition, we classified it as an ungrouped iron. Considering textural and mineralogical characteristics, Sirjan 001 shows similarities to an unofficial grouplet of meteorites called sulfide-irons, and is by far the largest of this type [1-4]. Studying rare iron meteorite types, such as Sirjan 001, provides valuable information on high-temperature parent body processes. Among such processes are melting and segregation of Fe-Ni-S-rich phases that led to local and/or regional differentiation of parent bodies, and the diversity of the objects in the Solar System. In this multi-method study, we investigate the origin and petrogenesis of Sirjan 001. Here, we discuss texture, mineralogy, bulk-rock composition, and chromite oxygen isotopic composition. Complementary to this report, we discuss the elemental and isotopic cosmochemistry of siderophile elements of Sirjan 001 in [5]. Methodology: We used a Bruker M4 Tornado μXRF instrument (AMGC, VUB) for mineralogical observations and elemental mapping. High-magnification petrography was performed using a PANalytical (Quanta 200) ESEM equipped with an EDAX (Apollo 10 CDD) EDS at the RBINS. For bulk-rock major and trace elemental analysis, we used Thermo Fisher Scientific iCAP (ICP-OES) and Agilent 7700 Q-ICP-MS at ULB. Samples for this step were prepared based on the method described in [6], which involved using aqua regia for dissolution. Oxygen isotopic composition of chromite was measured using a CAMECA SIMS 1270 E7 at CRPG-CNRS. Results: Sirjan 001 is a single stone with well-preserved regmaglypts showing minimal weathering in cut surface. Cut surface shows a gray metallic interior with metal-sulfide eutectic texture (Fig. 1). Irregular sulfides (troilite) are surrounded by Fe-Ni metal (Ni-rich and Ni-poor). Fe-Ni metal shapes are controlled by troilite outlines. Modal abundances (point counting; n=1000) of Fe-Ni metal and troilite, are 63% and 37%, respectively. Length measurement of 347 troilites yield the following values for mean, mode, and median: 1111±672 μm, 837 μm, and 894 μm, respectively. In addition, schreibersite occurs as an accessory mineral. A few crystals of chromite, graphite, pentlandite, and silicates are observed. Bulk composition concentrations are: Co=0.57, Ni=12.8 (wt%); Cu=320.7, Ga=20.0, Ge=42.4, As=8.4, Mo=4.9, W=0.7, Ir=3.7, Pd=5.6 (μg/g). Average mineral compositions measured by μXRF are (in wt%): Nipoor metal: Fe=93.6±0.08, Ni=6.11±0.03, Ni/Fe=0.07; Ni-rich metal: Fe=88.0±1.2, Ni=11.4±1.2, Ni/Fe=0.13; sulfide: Fe=80.5±1.7, S=19.6±1.8, Ni=1.9±0.1, S/Fe=0.25. Δ17O in two measured chromites are: #1: 0.53±0.43, 0.64±0.44 and #2: 0.50±0.45, 0.51±0.51 and fall on terrestrial fractionation line. Discussions and Conclusions: Based on textural, mineralogical, and chemical characteristics, Sirjan 001 shows similarities to MET 00428, HOW 88403, RBT 04162, RBT 04299, SaW 005, and Sahara 03505 ungrouped irons. These meteorites are known for their relatively high modal troilite contents compared to other irons. Their formation has been suggested to be related to impact melting in chondrite parent bodies [1-4]. We will discuss different scenarios involved in the formation of Sirjan 001 and compare it with similar meteorites and meteoritic components. [ABSTRACT FROM AUTHOR]

Introduction: Stable isotopes of moderately volatile elements (MVE) such as Cu and Zn are useful tools to investigate fractionation effects induced by condensation and evaporation. Ordinary chondrites (OC) may have experienced shock events on their parent bodies as they present multiple shock features, resulting in the loss of volatile elements and subsequent possible isotope fractionation of MVE. Those chondrites represent the most abundant group of meteorites with more than 85% of the total world collection. Yet they have been poorly studied for their stable isotope compositions. Results have been published but generally as part of broader studies (e.g. [1, 2]). Therefore, new stable isotopes data are required in order to reconcile literature data with the shock stage of OC and behavior of MVE isotopes. In the recent years, high precision isotope measurement of gallium, another MVE, has shown promising results regarding isotopic fractionation in volatility-controlled processes such as condensation and evaporation [3]. Gallium will be investigated together with Cu, Zn, and refractory Fe isotopes. These new measurements will be compared to previous studies in order to evaluate the possible shock effects on MVE isotopes in ordinary chondrites. In this study, H ordinary chondrites have been selected over the other subgroups (L and LL) because they exhibit the highest metallic iron content compared to the other ordinary chondrites [4]. The type-6 was preferred because of the high degree of thermal metamorphism they experienced; the homogenization induced would make it easier to highlight the isotope fractionation possibly generated during the shock event [5]. Samples and methods: A series of 15 H6 ordinary chondrites collected from Antarctica have been classified for their shock and weathering stages according to the classification established by [6] and [7], respectively. Chips of each sample weighing between 100 to 170 mg were gently crushed to powder in an agate mortar and dissolved using various mixtures of HNO3-HF-HCl acids. A 5% aliquot of each sample solution was taken before purification chemistry for trace elements measurements. Elemental data were collected by ICP-MS using two different instruments at ULB and VUB, each time applying In as internal standard. The total reproducibility estimated based on USGS reference materials is better than 10% RSD. Isotopic analyses were performed using the Nu plasma II HR-MC-ICP-MS at ULB relying on an Apex-Q desolvating sample introduction system. Results and Discussion: Out of the 15 H6 ordinary chondrites, we have classified based on shock stage 10 samples as S2, 2 samples S3, 1 sample S4, and 2 samples S5. As for weathering stage, 9 samples exhibited W1, 5 samples W2, and 1 sample W3. We report new bulk isotopic data for the MVE Zn, Cu, and the recently developed Ga as well as more refractory Fe in all H6 chondrites. Preliminary results show that the range of delta values for each isotope is negatively correlated with volatility, meaning that elements with lower 50% condensation temperature (Zn: 726 K, Ga: 968 K, Cu: 1037 K, and Fe: 1334 K [8]), appear to display larger degrees of isotope fractionation. We aim to link these variations to the observed shock degrees and weathering stages. The new data for Ga, together with Zn, Cu, and Fe values, will allow us to highlight possible shock-related effects caused during the impact events that were responsible for the ejection of the meteorites from their parent body/ies. Isotopic data in combination with trace element profiles could also help us to determine the role of weathering in fractionating those same isotope ratios, modifying and/or erasing the signal from the parent body/ies. [ABSTRACT FROM AUTHOR]

Introduction: Sirjan 001 is an ungrouped iron meteorite that was found in the Kerman province (Iran) in 2018. An accompanying study [1] reports the textural and mineralogical characteristics of Sirjan 001, where it is determined that Sirjan 001 shares similarities with the unofficial sulfide-rich meteorite grouplet termed "sulfide-irons" [2,3]. Sulfide-iron meteorites are rare in the meteorite collection, even though sulfide-rich melt is predicted to accompany metallic melts formed via fractional crystallization; the paucity of sulfide-rich irons and their relation to magmatic iron meteorites remain a cosmochemical enigma [4]. A study of the elemental and isotopic composition of Sirjan 001 was undertaken to determine its chemical and isotopic composition, age, and how the sample relates to iron meteorites. Methods: Concentrations for 20 elements were obtained using LA-ICP-MS (New Wave UP213 ultraviolet laser coupled to a Thermo Finnigan Element 2). Due to the high measured troilite content of ~37% volume [1], LA-ICPMS analyses were carried out as lines on the metal surfaces and spot analyses on troilite grains. A small piece (~0.06 g) was processed for highly siderophile element isotope dilution using published chemical separation and mass spectrometer techniques [5]. The remaining mass (~3 g) was digested for mass-independent isotopic analyses of Os, Pt, Mo, Ru and W using thermal ionization mass spectrometry (Thermo Finnigan Triton) and multi-collector ICP-MS (Thermo Finnigan Neptune Plus). All analytical work was carried out at the Isotope Geochemistry and Plasma Laboratories, University of Maryland. Results: Using the LA-ICP-MS data, a trace element "bulk" composition was calculated that accounts for the relative proportions of metal and sulfides in Sirjan 001. Bulk Ga and Ge concentrations indicate that Sirjan 001 is relatively enriched in volatile elements compared to magmatic iron groups IVA and IVB. On Ni vs. Ga, Ge, or Ir plots Sirjan 001 falls within the range of the magmatic IIIAB and the non-magmatic IAB and IIE groups. Osmium isotope measurements were conducted to determine cosmic ray exposure (CRE) effects, which can lead to the modification of Mo, Ru and W isotopic compositions. The µ189Os value for Sirjan 001 indicates minimal required CRE corrections. The nucleosynthetic 183W isotopic composition for Sirjan 001 is permissive of it being NC type, however, the Mo isotopic composition indicates either NC or a mix of NC-CC compositions. Ruthenium and Pt results will be reported. The 182W isotopic composition for Sirjan 001 corresponds to a metal-silicate segregation age of 5.2 ± 0.4 Myr after CAI formation. Discussion: Chemically, Sirjan 001 is most similar to the magmatic IIIAB irons and the non-magmatic IAB and IIE groups. To assess if Sirjan 001 is isotopically and/or temporally related to these meteorites, metal-silicate segregation ages and isotopic compositions are contrasted. Sirjan 001 is ~4 Myr younger than reported ages for magmatic iron meteorite groups (e.g., IIIAB) [6]. The 182W isotopic composition of Sirjan 001, however, is consistent with the reported values of several IAB and IIE irons, which have metal-silicate differentiation ages ranging from 4 to 27 Myr after CAI formation [7,8]. These ages likely represent re-equilibration of metal and silicate following modification to the parent bodies via impacts. Sirjan 001 has a mixed NC-CC composition, constrained by Mo isotopic data. This composition is similar to the ungrouped iron (sulfide-poor) Nedagolla, which was proposed to preserve isotopic evidence for early collisional mixing of NC and CC bodies [9]. The chemical and isotopic data suggest that Sirjan 001 is an ungrouped iron meteorite which may preserve early collisional mixing in the Solar System. As noted by [1], Sirjan 001 is chemically, texturally, and mineralogically similar to several ungrouped sulfide-rich meteorites. On-going work investigates the isotopic and temporal relations between Sirjan 001, Nedagolla, and sulfide-rich irons, and how these materials relate to collisional events in the protoplanetary disk. [ABSTRACT FROM AUTHOR]

The Qisir Dagh igneous complex occurs as a combination of volcanic and intrusive rocks to the south-east of the Sabalan volcano, north-western Iran. Micromonzogabbroic rocks in the region consist of plagioclase, alkaline feldspar and clinopyroxene as the major mineral phases and orthopyroxene, olivine, apatite and opaque minerals as the accessory minerals. Microgranular and microporphyritic textures are well developed in these rocks. Considering the importance of plagioclase in reconstructing magma cooling processes, the size and shape distribution and chemical composition of this mineral were investigated. Based on microscopic studies, it is shown that the 2-dimensional size average of plagioclase in the micromonzogabbros is 538 micrometers and its 3-dimensional shape varies between tabular to prolate. Crystal size distribution diagrams point to the presence of at least two populations of plagioclase, indicating the occurrence of magma mixing and/or fractional crystallization during magma cooling. The chemical composition of plagioclase shows a wide variation in abundances of Anorthite-Albite-Orthoclase (An=0.31–64.58, Ab=29.26–72.13, Or=0.9–66.97), suggesting a complex process during the crystal growth. This is also supported by the formation of antiperthite lamellae, which formed as the result of alkali feldspar exsolution in plagioclase. The calculated residence time of magma in Qisir Dagh, based on 3D crystal size distribution data, and using growth rate G=10−10 mm/s, varies between 457 and 685 years, which indicates a shallow depth (near surface) magma crystallization and subvolcanic nature of the studied samples.

Bauxite residues (BRs) are highly alkaline wastes generated during alumina production from bauxite ore. Billions of tons have been accumulating worldwide for more than 100 years, they are stored in various forms, and pose environmental and societal issues. At the same time, BRs are promising secondary sources for the production of critical metals including rare earth elements (REEs). However, knowledge on REE speciation is lacking, and is consequently an obstacle to the development of large-scale extraction process. This study analyses the influence of origin of the bauxite ore (lateritic or karstic), the storage conditions and storage time on the properties of ten BR samples, with a particular focus on the speciation of yttrium, which is used as a proxy to identify the behaviour of heavy REE. A multi-scale approach linked yttrium speciation and the origin of the bauxite ore whereas no major variation was observed as a function of storage conditions or ageing of the BRs. Yttrium is mainly found in the form of xenotime phosphate particles in BRs of lateritic origin, while in karstic BRs, the majority of yttrium is probably adsorbed or incorporated into other minerals including iron oxyhydroxide and hydroxyapatite minerals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Cerium is the most abundant rare earth element (REE) in the solar photosphere, CI chondrites, and the Earth. It has four main stable isotopes (masses: 136,138,140, and 142), with 138 Ce being the most studied species, used in geochronology and petrogenesis. In addition, more abundant 140 Ce and 142 Ce are suggested to be potentially applicable in geochemical investigations. In this work, we developed a modified four-step ion chromatography procedure for Ce chemical separation. Using a MC-ICPMS, we designed a cup configuration to measure 142 Ce/ 140 Ce ratio of the samples with an optimized Nd correction equation. A 0.03‰ (2SD) reproducibility was obtained for Ce Ames metal standard. We analyzed ten different igneous and one sedimentary geochemical reference materials. Mean δ 142 Ce range from -0.07 to 0.32‰. Most of the samples show a heavier Ce isotopic composition than the Ce Ames standard. The majority of rocks have a homogenous δ 142 Ce. The δ 142 Ce does not show any correlation with rock chemical composition including their Ce content or rock types. A carbonatite (SARM 40) has a mean δ 142 Ce of -0.07 ± 0.13‰ (2SD), lower than the other rocks, suggesting the possibility of a pronounced isotopic fractionation. Our work demonstrates the applicability of the developed methodology and the potential of Ce stable isotopes for future geochemical studies. Production of a larger database of δ 142 Ce values is required to obtain a clearer view on the similarities and differences between different geological material and explaining Ce stable isotope dynamics., (Copyright © 2020 Elsevier B.V. All rights reserved.)