ABSTRACTCalcium–aluminum‐rich inclusions (CAIs) in chondrites are one of the oldest materials in the solar system. Presence of refractory minerals in CAIs suggests that they formed thorough a condensation process from nebular gas of solar composition. In particular, fine‐grained CAIs (FGs) have escaped melting after condensation, and thus, the elemental distribution of rare earth elements (REEs) in FG minerals provides key information for elucidating the condensation processes. Although the REE abundances of FG fragments have been investigated in previous studies, the distribution of REEs in individual FG constituent minerals remains poorly explored. Here, we demonstrate the utility of laser imaging of REE distribution in CAIs by analyzing five FGs found in the Allende CV3 chondrite using multiple‐spot femtosecond laser ablation (msfsLA)‐ICP‐MS. The msfsLA‐ICP‐MS imaging system allows for a rapid acquisition of a wider range of REE distributions than previously achieved by Secondary ion mass spectrometry‐based imaging techniques. Out of the five FGs examined in this study, three showed the homogeneous REE patterns, while the other two indicated variable REE patterns within each FG. These observations presumably reflect differences in the chemical processes experienced by the FGs, and indicate that multi‐step chemical processes were recorded in some of the FGs. The msfsLA‐ICP‐MS imaging technique can characterize the elemental distribution of individual FGs under the comparable spatial resolution with high‐analysis throughput, and thus, it is an effective new method for advancing the taxonomy of FGs, which will improve our understanding of the physicochemical conditions that prevailed in the early solar system.

The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk's lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites.

The surface chemistry of pyrrhotites from intact particles directly collected from asteroid (162173) Ryugu was investigated by micro-Raman spectroscopy. The Raman peak characteristic to pyrrhotite was observed at around 115 cm-1 in Ryugu pyrrhotites, similar to freshly cleaved surfaces of terrestrial pyrrhotites. Additional Raman bands centered at around 220, 275, and 313 cm-1 with broadened features were also detected from the Ryugu pyrrhotites. The set of Raman bands at 220 and 275 cm-1 was assigned to typical Fe-S stretching vibrations of nu 2 (225 cm-1 ) and nu 1 (275 cm-1 ). These bands are not clearly observed in bulk crystals of pyrrhotite but appear in its nanoparticulate phase. These bands are ordinarily seen in amorphous monosulfides that formed under low oxygen fugacity ( f O 2 ) conditions in nature, indicating that the structural alteration of pyrrhotite surfaces occurred heterogeneously on the nanoscale under low f O 2 conditions. Further, the Raman band at 313 cm-1 was attributed to a characteristic tetrahedral bonding of Fe(III) in the lattice of Fe II 1-3x Fe III 1-2x S, followed by the local breakdown of the crystal lattice structures from planar bonding with Fe(II). In addition, some areas of the Ryugu pyrrhotite grains showed corroded structures with iridescence. Furthermore, assemblages of magnetite particles were also preferentially observed on small areas of the likely-dissolved pyrrhotite crystals in phyllosilicate matrices. These characteristic features in the Raman spectra and in corroded structures of Ryugu pyrrhotites record changes in the local environmental conditions via aqueous alteration. The corrosion of pyrrhotite crystals followed by the preferential formation of magnetite particles by asteroidal water is the likely product of dissolution of Fe(II) from the pyrrhotite surface and its oxidative precipitation in microchemical environments on the Ryugu parent body.

C-type asteroids are the presumed home to carbonaceous chondrites, some of which contain abundant life forming volatiles and organics. For the first time, samples from a C-type asteroid (162173 Ryugu) were successfully returned to Earth by JAXA's Hayabusa2 mission. These pristine samples, uncontaminated by the terrestrial environment, allow a direct comparison with carbonaceous chondrites. This study reports the stable K isotopic compositions (expressed as 841K) of Ryugu samples and seven carbonaceous chondrites to constrain the origin of K isotopic variations in the early Solar System. Three aliquots of Ryugu particles collected at two touchdown sites have identical 841K values, averaged at-0.194 +/- 0.038%o (2SD). The K isotopic composition of Ryugu falls within the range of 841K values measured on representative CI chondrites, and together, they define an average 841K value of-0.185 +/- 0.078%o (2SE), which provides the current best estimate of the K isotopic composition of the bulk Solar System. Samples of CI chondrites with 841K values that deviate from this range likely reflect terrestrial contaminations or compositional heterogeneities at sampled sizes. In addition to CI chondrites, substantial K isotopic variability is observed in other carbonaceous chondrites and within individual chondritic groups, with 841K values inversely correlated with K abundances in many cases. These observations indicate widespread fluid activity occurred in chondrite parent bodies, which significantly altered the original K abundances and isotopic compositions of chondrules and matrices established at their accretion.

Oxygen 3-isotope ratios of magnetite and carbonates in aqueously altered carbonaceous chondrites provide important clues to understanding the evolution of the fluid in the asteroidal parent bodies. We conducted oxygen 3-isotope analyses of magnetite, dolomite, and breunnerite in two sections of asteroid Ryugu returned samples, A0058 and C0002, using a secondary ion mass spectrometer (SIMS). Magnetite was analyzed by using a lower primary ion energy that reduced instrumental biases due to the crystal orientation effect. We found two groups of magnetite data identified from the SIMS pit morphologies: (1) higher delta O-18 (from 3 parts per thousand to 7 parts per thousand) and O-17 (similar to 2 parts per thousand) with porous SIMS pits mostly from spherulitic magnetite, and (2) lower delta O-18 (similar to -3 parts per thousand) and variable O-17 (0 parts per thousand-2 parts per thousand) mostly from euhedral magnetite. Dolomite and breunnerite analyses were conducted using multi-collection Faraday cup detectors with precisions <= 0.3 parts per thousand. The instrumental bias correction was applied based on carbonate compositions in two ways, using Fe and (Fe+Mn) contents, respectively, because Ryugu dolomite contains higher amounts of Mn than the terrestrial standard. Results of dolomite and breunnerite analyses show a narrow range of O-17; 0.0 parts per thousand-0.3 parts per thousand for dolomite in A0058 and 0.2 parts per thousand-0.8 parts per thousand for dolomite and breunnerite in C0002. The majority of breunnerite, including large >= 100 mu m grains, show systematically lower delta O-18 (similar to 21 parts per thousand) than dolomite (25 parts per thousand-30 parts per thousand and 23 parts per thousand-27 parts per thousand depending on the instrumental bias corrections). The equilibrium temperatures between magnetite and dolomite from the coarse-grained lithology in A0058 are calculated to be 51 +/- 11 degrees C and 78 +/- 14 degrees C, depending on the instrumental bias correction scheme for dolomite; a reliable temperature estimate would require a Mn-bearing dolomite standard to evaluate the instrumental bias corrections, which is not currently available. These results indicate that the oxygen isotope ratios of aqueous fluids in the Ryugu parent asteroid were isotopically heterogeneous, either spatially, or temporary. Initial water ice accreted to the Ryugu parent body might have O-17>2 parts per thousand that was melted and interacted with anhydrous solids with the initial O-17<0 parts per thousand. In the early stage of aqueous alteration, spherulitic magnetite and calcite formed from aqueous fluid with O-17 similar to 2 parts per thousand that was produced by isotope exchange between water (O-17>2 parts per thousand) and anhydrous solids (O-17<0 parts per thousand). Dolomite and breunnerite, along with some magnetite, formed at the later stage of aqueous alteration under higher water-to-rock ratios where the oxygen isotope ratios were nearly at equilibrium between fluid and solid phases. Including literature data, delta O-18 of carbonates decreased in the order calcite, dolomite, and breunnerite, suggesting that the temperature of alteration might have increased with the degree of aqueous alteration.

We report Nd and Sm isotopic compositions of four samples of Ryugu returned by the Hayabusa2 mission, including "A" (first touchdown) and "C" (second touchdown) samples, and several carbonaceous chondrites to evaluate potential genetic relationships between Ryugu and known chondrite groups and track the cosmic ray exposure history of Ryugu. We resolved Nd and Sm isotopic anomalies in small (<20 ng Nd and Sm) sample sizes via thermal ionization mass spectrometer using 10(13) Omega amplifiers. Ryugu samples exhibit resolvable negative mu Nd-142 values consistent with carbonaceous chondrite values, suggesting that Ryugu is related to the parent bodies of carbonaceous chondrites. Ryugu's negative mu Sm-149 values are the result of exposure to galactic cosmic rays, as demonstrated by the correlation between Sm-150/Sm-152 and Sm-149/Sm-152 ratios that fall along the expected neutron capture correlation line. The neutron fluence calculated in the "A" samples (2.75 +/- 1.94 x 10(15) n cm(-2)) is slightly higher compared to the "C" samples (0.95 +/- 2.04 x 10(15) n cm(-2)), though overlapping within measurement uncertainty. The Sm results for Ryugu, at this level of precision, thus are consistent with a well-mixed surface layer at least to the depths from which the "A" and "C" samples derive.

We present oxygen isotopic analyses of fragments of the near-Earth C b -type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites. Small differences between Ryugu samples and CI chondrites in Δ ′ 17 O can be explained at least in part by contamination of the latter by terrestrial water. The discovery that a randomly sampled C-complex asteroid is composed of CI-chondrite-like rock, combined with thermal models for formation prior to significant decay of the short-lived radioisotope 26 Al, suggests that if lithified at the time of alteration, the parent body was small (≪50 km radius). If the parent planetesimal was large (>50 km in radius), it was likely composed of high-permeability, poorly lithified sediment rather than consolidated rock.

Calcium-aluminum-rich inclusions (CAIs) in chondrite meteorites are the oldest rocks in the Solar System and were formed by condensation from nebular gas. Recent mass spectrometric measurements have revealed that CAIs possess nucleosynthetic isotopic compositions different from those of terrestrial mate-rials for various elements, indicating a heterogeneous distribution of nuclides from various stellar sources in the early Solar System. CAIs are classified into coarse-grained (CGs) and fine-grained (FGs) inclusions. The former have experienced secondary melting through thermal events after their formation, while the latter evidently avoided the remelting. Thus, FGs are considered to be direct condensates from a high -temperature gas, making them ideal for the investigation of the origin and formation process of CAIs. In this study, the elemental abundances and Sr isotopic compositions in eight FGs from a carbonaceous chondrite Allende were analyzed by utilizing a micromilling technique. These FG samples were found to have rare-earth element (REE) patterns reflecting various degrees of elemental fractionation and variable mu 84Sr values ranging from 61 to 844 ppm. It cannot be ruled out that matrix contamination during micro -milling or secondary alteration on the Allende parent body has affected the elemental abundances and mu 84Sr values observed in FGs to some extent; however, the large variation in mu 84Sr values could reflect the variability in the FG formation processes. Importantly, REE-fractionated FGs, which were depleted in heavy REEs relative to light REEs, had relatively high mu 84Sr values. This suggests that the formation of REE-fractionated FGs was triggered by rapid heating events, such as FU Orionis that occurred period-ically in the early Solar System, and that at least two different heating events probably formed FGs with two different mu 84Sr values.(c) 2023 Elsevier Ltd. All rights reserved.

Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between 54 Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred 5.2 − 1.4 + 1.8 Ma after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.

Rock fragments of the Cb-type asteroid Ryugu returned to Earth by the JAXA Hayabusa2 mission share mineralogical, chemical, and isotopic properties with the Ivuna-type (CI) carbonaceous chondrites. Similar to CI chondrites, these fragments underwent extensive aqueous alteration and consist predominantly of hydrous minerals likely formed in the presence of liquid water on the Ryugu parent asteroid. Here we present an in situ analytical survey performed by secondary ion mass spectrometry from which we have estimated the D/H ratio of Ryugu’s hydrous minerals, D/H _Ryugu , to be [165 ± 19] × 10 ^−6 , which corresponds to δ D _Ryugu = +59 ± 121‰ (2 σ ). The hydrous mineral D/H _Ryugu ’s values for the two sampling sites on Ryugu are similar; they are also similar to the estimated D/H ratio of hydrous minerals in the CI chondrites Orgueil and Alais. This result reinforces a link between Ryugu and CI chondrites and an inference that Ryugu’s samples, which avoided terrestrial contamination, are our best proxy to estimate the composition of water at the origin of hydrous minerals in CI-like material. Based on this data and recent literature studies, the contribution of CI chondrites to the hydrogen of Earth’s surficial reservoirs is evaluated to be ∼3%. We conclude that the water responsible for the alteration of Ryugu’s rocks was derived from water ice precursors inherited from the interstellar medium; the ice partially re-equilibrated its hydrogen with the nebular H _2 before being accreted on the Ryugu’s parent asteroid.

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37° ± 10°C, about [Formula: see text] million (statistical) or [Formula: see text] million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles that of the Sun's photosphere than other natural samples do.

The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system. In 2020 December, the Japan Aerospace Exploration Agency Hayabusa2 spacecraft returned to Earth the first samples of a primitive asteroid, namely, the Cb-type asteroid Ryugu. This provides a unique opportunity to explore the kinship between primitive asteroids and carbonaceous chondrites. We report high-precision μ ^26 Mg* and μ ^25 Mg values of Ryugu samples together with those of CI, CM, CV, and ungrouped carbonaceous chondrites. The stable Mg isotope composition of Ryugu aliquots defines μ ^25 Mg values ranging from –160 ± 20 ppm to –272 ± 30 ppm, which extends to lighter compositions relative to Ivuna-type (CI) and other carbonaceous chondrite groups. We interpret the μ ^25 Mg variability as reflecting heterogeneous sampling of a carbonate phase hosting isotopically light Mg ( μ ^25 Mg ∼ –1400 ppm) formed by low temperature equilibrium processes. After correcting for this effect, Ryugu samples return homogeneous μ ^26 Mg* values corresponding to a weighted mean of 7.1 ± 0.8 ppm. Thus, Ryugu defines a μ ^26 Mg* excess relative to the CI and CR chondrite reservoirs corresponding to 3.8 ± 1.1 and 11.9 ± 0.8 ppm, respectively. These variations cannot be accounted for by in situ decay of ^26 Al given their respective ^27 Al/ ^24 Mg ratios. Instead, it requires that Ryugu and the CI and CR parent bodies formed from material with a different initial ^26 Al/ ^27 Al ratio or that they are sourced from material with distinct Mg isotope compositions. Thus, our new Mg isotope data challenge the notion that Ryugu and CI chondrites share a common nucleosynthetic heritage.

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.e., microenergy-dispersive X-ray fluorescence (micro-XRF) and Raman micro-spectroscopy. The applicability of the developed method is tested by the quantitative analysis of cation composition in micrometer-sized carbonate grains on the surfaces of intact particles sampled directly from the asteroid Ryugu. The first step of micro-XRF imaging enabled a quick search for the sparsely scattered and micrometer-sized carbonates by the codistributions of Ca2+ and Mn2+ on the Mg2+- and Fe2+-rich phyllosilicate matrix. The following step of Raman micro-spectroscopy probed the carbonate grains and analyzed their cation composition (Ca2+, Mg2+, and Fe2+ + Mn2+) in a matrix effect-free manner via the systematic Raman shifts of the lattice modes. The carbonates were basically assigned to ferroan dolomite bearing a considerable amount of Fe2+ + Mn2+ at around 10 atom %. These results are in good accordance with the assignments reported by scanning electron microscopy-energy-dispersive X-ray spectroscopy, where the thin-sectioned and surface-polished Ryugu particles were applicable. The proposed method requires neither sectioning nor surface polishing; hence, it can be applied to the remote sensing apparatus on spacecrafts and planetary rovers. Furthermore, the non-invasive and matrix effect-free characterization will provide a reliable analytical tool for quantitative analysis of the elemental distribution on the samples with surface roughness and chemical heterogeneity at a micrometer scale, such as art paintings, traditional crafts with decorated shapes, as well as sands and rocks with complex morphologies in nature.

The Hayabusa2 spacecraft explored asteroid Ryugu and brought its surface materials to Earth. Ryugu samples resemble Ivuna-type (CI) chondrites—the most chemically primitive meteorites—and contain secondary phyllosilicates and carbonates, which are indicative of aqueous alteration. Understanding the conditions (such as temperature, redox state and fluid composition) during aqueous alteration is crucial to elucidating how Ryugu evolved to its present state, but little is known about the temporal changes in these conditions. Here we show that calcium carbonate (calcite) grains in Ryugu and Ivuna samples have variable 18 O/ 16 O and 13 C/ 12 C ratios that are, respectively, 24–46‰ and 65–108‰ greater than terrestrial standard values, whereas those of calcium–magnesium carbonate (dolomite) grains are much more homogeneous, ranging within 31–36‰ for oxygen and 67–75‰ for carbon. We infer that the calcite precipitated first over a wide range of temperatures and oxygen partial pressures, and that the proportion of gaseous CO 2 /CO/CH 4 molecules changed temporally. By contrast, the dolomite formed later in a more oxygen-rich and thus CO 2 -dominated environment when the system was approaching equilibrium. The characteristic isotopic compositions of secondary carbonates in Ryugu and Ivuna are not observed for other hydrous meteorites, suggesting a unique evolutionary pathway for their parent asteroid(s).

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugu’s rubble pile origin.

The surface samples from a primitive carbonaceous asteroid Ryugu were successfully brought back by the Hayabusa2 spacecraft in 2020.The primary curation phase and subsequent initial analyses revealed that the Ryugu samples are similar to CI chondrites [1,2].Here, we report preliminary results on the Pb isotopic compositions obtained from the Ryugu samples for their further characterization.Four Ryugu samples [two samples from the first touchdown (A0106-0107) and two samples from the second touchdown (C0107-0108)] and three carbonaceous chondrites [Tagish Lake, Murchison, and Orgueil] were examined in this study.The Pb fractions were prepared using ion-exchange procedures following sample digestion [2], and unspiked and 207 Pb-204 Pb double-spiked samples prepared from a single dissolution were measured with TIMS (Triton plus) at Tokyo Tech.The Pb isotopic data for Ryugu samples and carbonaceous chondrites from this study, as well as the literature data for Murchison and Allende bulk samples [3] and Allende matrix samples [4], form a straight array that closely passes through the primordial Pb compositions defined by troilites in iron meteorites [5,6] (Fig. 1).The Ryugu Pb isotopic compositions show variations but are indistinguishable between the samples from the first and second touchdown sites.They are less radiogenic than in most analyzed carbonaceous chondrites, indicating lower content of chondrule-or CAI-like refractory material depleted in moderately volatile elements.The y-intercept of the regression yields an age of 4577.9 ± 7.1 Ma, which is older than the age of Solar System formation (4567.3 ± 0.16 Ma [7]).As discussed in [4], this old age could be related to the presence of various components in chondrites with different ages and 238 U/ 235 U ratios.This research was conducted by the teamwork of the Hayabusa2-initial-analysis chemistry team and the Hayabusa2initial-analysis core.

Initial analyses showed that asteroid Ryugu’s composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) – the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu’s pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth’s mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth’s budgets of Zn and other moderately volatile elements. A comparison of copper and zinc isotopic measurements between the Ryugu samples and various carbonaceous chondrites excludes any genetic link between the two except for the CI (Ivuna-type) chondrites. Ryugu-like material might have accounted for ~5% of Earth’s mass.

Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inward to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.

Calcium and aluminum-rich inclusions (CAIs) in chondrites are one of the oldest materials in the solar system.The constituent refractory minerals in CAIs suggest that they were formed by direct condensation from nebular gas of solar system composition [1-2].Unlike coarse-grained CAIs, fine-grained CAIs (FGs) are thought to have escaped remelting.Therefore, the elemental distribution in FG minerals, specifically for rareearth elements (REEs), provides key information to understand the condensation processes.In previous studies, formation processes of FG minerals have discussed using the CInormalized REE abundance patterns in fragments FGs consisting of multiple minerals [3][4].Therefore, the distribution of REEs in individual FG minerals remains unclear.In this study, we performed imaging measurements for five FGs in Allende meteorite using LA-ICP-MS.The abundances of major elements and REEs obtained by the imaging were analyzed in association with the mineral distribution data obtained by SEM-EDS performed prior to the imaging measurements.Most of the analyzed FGs showed fractionated REE patterns that are typically observed in FGs.In three out of the five FGs, the REE abundances varied across different minerals with the highest abundances in Ti-rich calcic pyroxene, while individual minerals essentially have similar REE patterns.In contrast, the other two FGs showed different REE patterns for different minerals.In particular, for an FG with layered structure, a unique REE pattern with Gd-Ho enrichment was observed at the layer boundary, which is difficult to explain with previous FG formation models.The diverse REE patterns within single FGs suggests the presence of multiple gaseous reservoirs that contributed to the formation of FGs examined in this study.