Artigos de revistas: "Meteorites Analysis"

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Wampler, James, Mark Thiemens, Shaobo Cheng, Yimei Zhu e Ivan K. Schuller. "Superconductivity found in meteorites". Proceedings of the National Academy of Sciences 117, n.º 14 (23 de março de 2020): 7645–49. http://dx.doi.org/10.1073/pnas.1918056117.

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Meteorites can contain a wide range of material phases due to the extreme environments found in space and are ideal candidates to search for natural superconductivity. However, meteorites are chemically inhomogeneous, and superconducting phases in them could potentially be minute, rendering detection of these phases difficult. To alleviate this difficulty, we have studied meteorite samples with the ultrasensitive magnetic field modulated microwave spectroscopy (MFMMS) technique [J. G. Ramírez, A. C. Basaran, J. de la Venta, J. Pereiro, I. K. Schuller,Rep. Prog. Phys.77, 093902 (2014)]. Here, we report the identification of superconducting phases in two meteorites, Mundrabilla, a group IAB iron meteorite [R. Wilson, A. Cooney,Nature213, 274–275 (1967)] and GRA 95205, a ureilite [J. N. Grossman,Meteorit. Planet. Sci.33, A221–A239 (1998)]. MFMMS measurements detected superconducting transitions in samples from each, above 5 K. By subdividing and remeasuring individual samples, grains containing the largest superconducting fraction were isolated. The superconducting grains were then characterized with a series of complementary techniques, including vibrating-sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDX), and numerical methods. These measurements and analysis identified the likely phases as alloys of lead, indium, and tin.

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Drouard, A., P. Vernazza, S. Loehle, J. Gattacceca, J. Vaubaillon, B. Zanda, M. Birlan et al. "Probing the use of spectroscopy to determine the meteoritic analogues of meteors". Astronomy & Astrophysics 613 (maio de 2018): A54. http://dx.doi.org/10.1051/0004-6361/201732225.

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Context. Determining the source regions of meteorites is one of the major goals of current research in planetary science. Whereas asteroid observations are currently unable to pinpoint the source regions of most meteorite classes, observations of meteors with camera networks and the subsequent recovery of the meteorite may help make progress on this question. The main caveat of such an approach, however, is that the recovery rate of meteorite falls is low (<20%), implying that the meteoritic analogues of at least 80% of the observed falls remain unknown. Aims. Spectroscopic observations of incoming bolides may have the potential to mitigate this problem by classifying the incoming meteoritic material. Methods. To probe the use of spectroscopy to determine the meteoritic analogues of incoming bolides, we collected emission spectra in the visible range (320–880 nm) of five meteorite types (H, L, LL, CM, and eucrite) acquired in atmospheric entry-like conditions in a plasma wind tunnel at the Institute of Space Systems (IRS) at the University of Stuttgart (Germany). A detailed spectral analysis including a systematic line identification and mass ratio determinations (Mg/Fe, Na/Fe) was subsequently performed on all spectra. Results. It appears that spectroscopy, via a simple line identification, allows us to distinguish the three main meteorite classes (chondrites, achondrites and irons) but it does not have the potential to distinguish for example an H chondrite from a CM chondrite. Conclusions. The source location within the main belt of the different meteorite classes (H, L, LL, CM, CI, etc.) should continue to be investigated via fireball observation networks. Spectroscopy of incoming bolides only marginally helps precisely classify the incoming material (iron meteorites only). To reach a statistically significant sample of recovered meteorites along with accurate orbits (>100) within a reasonable time frame (10–20 years), the optimal solution may be the spatial extension of existing fireball observation networks.

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Costa, Benilde F. O., Eduardo Ivo Alves, Pedro A. O. C. Silva e António C. Batista. "57Fe Mössbauer Analysis of Meteorites and Tektites". Minerals 11, n.º 6 (12 de junho de 2021): 628. http://dx.doi.org/10.3390/min11060628.

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This review presents studies on iron meteorites (Campo del Cielo fall and an unregistered iron meteorite), an unregistered stony meteorite from Northwest Africa, and 13 tektites from the American, European, and Australasian strewn fields. The main experimental technique used in the studies was Mössbauer spectroscopy, both in transmission and backscattering geometries. For the latter, a MIMOS II spectrometer was used. Additionally, optical and scanning electron microscopies and X-ray diffraction were used. In the studied iron meteorites, kamacite is found as the main mineral. Campo del Cielo meteorite exhibits Widmanstätten patterns and schreibersite inclusions. The unregistered iron meteorite has Neumann lines and schreibersite inclusions. We have assigned Campo del Cielo as an octahedrite and the unregistered iron meteorite as a hexahedrite. The unregistered stony meteorite is composed mainly of iron-free silicates; at 4.2 K, the spectrum indicates maghemite and 1% troilite. The Cambodian tektite appeared individualized from other australasites, unlike the moldavite, which tends to cluster with them. Our analyses do not allow dismissing doubts on the provenance of tibetanites. The Fe3+/Fe2+ ratio was found to be higher for Muong Nong-type tektites than for splash-form tektites, as expected from their morphology and solidification from melt at lower temperature.

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Wagle, Bivu, Kaustuv Regmi e Krishna Prasad Adhikari. "Study of Fall Meteorites Over a Century (1922-2021)". BMC Journal of Scientific Research 5, n.º 1 (31 de dezembro de 2022): 97–105. http://dx.doi.org/10.3126/bmcjsr.v5i1.50680.

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Fall meteorites represents to those meteorites whose fall has been witnessed and are later collected from earth surface for further studies. Mass, number of fall events, types, type mass and mass trend of observed fall meteorites are analyzed over a period of recent century (1922-2021) in this paper. The total number of fall meteorites was found to be 706 with total mass of 42800 kg. Decade 2012-2021 and 1932-1941 had the highest number of recorded fall which was 94 times and 89 times respectively. Type L6 meteorite was found to have the greatest number of falls which is 151 times, followed by type H5 and L5 with 109 times and 55 times respectively. The meteorite of type, Iron III AB had the greatest meteorites mass of 23480 kg followed by H5 and L6 with mass 6615 kg and 2347.362 kg respectively. The massive meteorite fall of this century was of Iron III AB type (1947) which weighed 23 tones. The decade 1942-1951 had the highest fall meteorites mass of 24806kg and 1972-1981 had 4858 kg. Various regression model is fitted for the trend analysis of the mass. Over a period of this century, meteorites having mass greater than 100 kg has struck the earth for 32 times while mass greater than 1000 kg has struck for 6 times. The average time between two impacts of meteorite with mass greater than 100kg was calculated to be 3.12 years while mass greater than 1000 kg was found to be 16.6 years.

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PEREIRA, GONZALO. "¿TIENEN EL MISMO ORIGEN LOS METEORITOS METÁLICOS ENCONTRADOS EN BOLIVIA?" Revista Boliviana de Física 38, n.º 38 (30 de novembro de 2021): 10–14. http://dx.doi.org/10.53287/eohr3986hv72b.

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While reconstructing the history of meteorites related to Bolivia, we found that the only two metallic meteorites classified as “Found in Bolivia” are the Bolivia and Pooposo meteorites. They are classified within the group of MG IAB iron meteorites and have a similar history. Both were seriously mishandled before reaching the hands of meteorite experts and were commercialized by a priest. In light of these possible matches, some experts have recommended a comparative study of both meteorites to ascertain if they could be part of the same object. In this paper we analyze the data of abundant chemical elements found in both meteorites. The data was obtained from different analyses carried out on all known iron meteorites through methods such as: Radiochemical Neutron Activation Analysis (RNAA) and Instrumental Neutron Activation Analysis (INAA). These data have been published by different researchers: Buchwald (1975a); Scott (1978); Kracher et al. (1980); Wasson & Kallemeyn (2002). Our objective has been to determine if both specimens are part of a larger object that impacted on the surface of the Oruro plateau or if they are simply two independent iron meteorites.

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Minčeva-Šukarova, Biljana. "Meteorite Struga – overview of previous chemical and recent spectroscopic analyses". Macedonian Journal of Chemistry and Chemical Engineering 28, n.º 1 (15 de junho de 2009): 41. http://dx.doi.org/10.20450/mjcce.2009.220.

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Meteorite Struga fell more than 35 years ago near the town of Struga, Republic of Macedonia. Its fall was notified in the Bulletien of the Geological Institute in Skopje in 1973. Since that time, only one chemical analysis has been reported (in 1990) and most recently, preliminary spectrosocpic investigations (in 2006 and in 2008) have been performed. However, this meteorite has not yet been classified in the World’s Database of Meteorites. The aim of this paper is to collect and summarize all available data published until now on this meteorite and open the possibility to clasify it and list it in the World’s Database of Meteorites. In order to make the results more available, the details of the previous chemical and the recent spectrosocpic analyses on this meteorite are presented in this paper. Collected information from both analyses were used for the description of the characteristics of this meteorite. Previous chemical analysis and the recent spectrosocpic investigations are in good agreement and confirm the earlier classification of this meteorite as stony chondrite of H type.

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Martins, Zita. "Organic molecules in meteorites". Proceedings of the International Astronomical Union 11, A29B (agosto de 2015): 411–15. http://dx.doi.org/10.1017/s1743921316005676.

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AbstractThe analysis of the organic content of meteorites provides a window into the conditions of the early solar system, such as the extension of aqueous alteration or thermal metamorphism on the meteorite parent bodies. The analysis of the soluble organic content of CM chondrites indicates that extensive aqueous alteration on their meteorite parent body may result on 1) the decomposition of α-amino acids; 2) synthesis of β- and γ-amino acids; 3) higher relative abundances of alkylated polycyclic aromatic hydrocarbons (PAHs); and 4) higher L-enantiomer excess (Lee) value of isovaline. Exogenous delivery of organic matter by meteorites may have contributed to the organic inventory of the early Earth, providing a diversity of resources to the first living organisms on Earth and on other places of our solar system where life could have potentially originated.

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Rai, Abhishek K., Jayanta K. Pati, Christian G. Parigger, Sonali Dubey, Awadhesh K. Rai, Balen Bhagabaty, Amulya C. Mazumdar e Kalpana Duorah. "The Plasma Spectroscopic Study of Dergaon Meteorite, India". Molecules 25, n.º 4 (22 de fevereiro de 2020): 984. http://dx.doi.org/10.3390/molecules25040984.

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Meteorites are the recoverable portions of asteroids that reach the surface of the Earth. Meteorites are rare extraterrestrial objects studied extensively to improve our understanding of planetary evolution. In this work, we used calibration-free laser-induced breakdown spectroscopy (CF-LIBS) to evaluate the quantitative elemental and molecular analyses of the Dergaon meteorite, a H 4-5 chondrite fall sample from Assam, India. Spectral signatures of H, N, O, Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, andIrweredetected. Along with the atomic emission, this work reports the molecular emission from FeO molecules. The concentration of the measured elements obtained using CF-LIBS is in close agreement with earlier reports. The elements H, N, and O and their concentrations are estimated by using CF-LIBS for the first time. This study applies laser spectroscopy to establish the presence of Ni, Cr, Co, and Ir in meteorites. The elemental analysis forms the basis for the establishment of the potential molecular composition of the Dergaon meteorite. Moreover, the elemental analysis approach bodes well for in-situ analyses of extraterrestrial objects including applications in planetary rover missions.

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Cooper, George, Andro Rios e Michel Nuevo. "Monosaccharides and Their Derivatives in Carbonaceous Meteorites: A Scenario for Their Synthesis and Onset of Enantiomeric Excesses". Life 8, n.º 3 (27 de agosto de 2018): 36. http://dx.doi.org/10.3390/life8030036.

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Carbonaceous meteorites provide the best glimpse into the solar system’s earliest physical and chemical processes. These ancient objects, ~4.56 billion years old, contain evidence of phenomena ranging from solar system formation to the synthesis of organic compounds by aqueous and (likely) low-temperature photolytic reactions. Collectively, chemical reactions resulted in an insoluble kerogen-like carbon phase and a complex mixture of discrete soluble compounds including amino acids, nucleobases, and monosaccharide (or “sugar”) derivatives. This review presents the documented search for sugars and their derivatives in carbonaceous meteorites. We examine early papers, published in the early 1960s, and note the analytical methods used for meteorite analysis as well as conclusions on the results. We then present the recent finding of sugar derivatives including sugar alcohols and several sugar acids: The latter compounds were found to possess unusual “d” enantiomeric (mirror-image) excesses. After discussions on the possible roles of interstellar grain chemistry and meteorite parent body aqueous activity in the synthesis of sugar derivatives, we present a scenario that suggests that most of Earth’s extraterrestrial sugar alcohols (e.g., glycerol) were synthesized by interstellar irradiation and/or cold grain chemistry and that the early solar disk was the location of the initial enantiomeric excesses in meteoritic sugar derivatives.

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Boaca, Ioana, Maria Gritsevich, Mirel Birlan, Alin Nedelcu, Tudor Boaca, François Colas, Adrien Malgoyre, Brigitte Zanda e Pierre Vernazza. "Characterization of the Fireballs Detected by All-sky Cameras in Romania". Astrophysical Journal 936, n.º 2 (1 de setembro de 2022): 150. http://dx.doi.org/10.3847/1538-4357/ac8542.

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Abstract Some of the fields of research that have captured the persistent interest of both scientists and the general public are meteor phenomena. The main goal in the study of meteoroid impacts into Earth’s atmosphere is the recovery of the remnant matter after the ablation in the form of meteorites. This is a complementary approach, yet cheap alternative, to a sample return mission. Meteoroids are messengers since the time of the formation of the solar system due to the fact that they have preserved the same composition. The study of meteorites provides information regarding the chemical composition from which the planets formed. The increasing number of all-sky camera networks in recent years has resulted in a large set of events available for study. Thus, it is very important to use a method that determines whether the meteoroid could produce a meteorite or not. In this paper we study the meteors detected by the FRIPON network in Romania with the use of all-sky cameras. We focus on the events with noticeable deceleration (V f /V 0 < 0.8). We determine the ballistic coefficient α and the mass-loss parameter β for the selected sample. Based on this analysis the events are classified in three categories: (1) meteoroids that are likely to produce meteorites; (2) meteoroids that can possibly produce meteorites; (3) meteoroids that are unlikely to produce meteorites. The entry and final mass are determined for each event. From the recorded fireballs, we identified one possible meteorite dropper, and we analyzed its dynamical evolution.

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Nabawy, Bassem S. "Modeling the Electric and Dielectric Behaviors of the Gebel Kamil Iron Meteorite". Natural Resources Research 31, n.º 1 (28 de janeiro de 2022): 179–89. http://dx.doi.org/10.1007/s11053-021-10007-6.

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AbstractThe Gebel Kamil iron meteorite is a famous big meteorite, and it is considered among the rare well-preserved iron meteorites. In this study, its electric and dielectric properties, namely electric conductivity (σ), dielectric constant (ε′), and dielectric loss (ε″), were measured using alternating current at a wide range of frequencies (50 Hz–11.0 MHz). This electrical characterization process was performed to get a diagnostic electric behavior of the electric and dielectric parameters as a function of the applied frequency (f). It is revealed that, by increasing f, the σ increased, while the dielectric properties decreased systematically through three stages of frequency. The well-known octahedral structure of iron meteorites was imaged using scanning electron microscopy (SEM) with support by energy-dispersive X-ray analysis (EDAX) to analyze the chemical composition of the meteorite specimen. The EDAX indicated that the Gebel Kamil meteorite is a Ni–Fe alloy with no impurities (Ni = 20.4–22.3%, Fe = 77.7–79.6%). This chemical composition and the electric and dielectric behaviors of the studied Ni-rich Gebel Kamil meteorite specimen can be recorded as diagnostic features and properties of this Fe–Ni meteorite.

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do Nascimento-Dias, Bruno Leonardo, Maria Elizabeth Zucolotto, Hugo Camarano Belgo, Talita Valverde Ferreira da Silva e Virgĩlio de Carvalho dos Anjos. "Detection of organic or inorganic material in Martian meteorite Zagami by vibrational spectroscopy?" International Journal of Astrobiology 19, n.º 6 (14 de setembro de 2020): 438–45. http://dx.doi.org/10.1017/s147355042000021x.

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AbstractZagami is a basaltic shergottite well characterized among Martian meteorites. For this reason, it is used as a reference sample to verify the feasibility of the vibrational spectroscopy techniques. In general, these techniques seeking extract spectral signatures from individual mineral present in the meteorite samples. Among some FTIR results were detected organic compounds in the Zagami meteorite and recorded in some articles. Based on these results, an analysis of a Zagami meteorite sample was performed using FTIR and Raman spectrometry. Examining the fragment of Zagami meteorite using the FTIR technique, it was possible to identify the same band of 2920 and 2850 cm−1 described by other references, which were interpreted as organic components and were recorded such as aliphatic hydrocarbon. Another unusual result in Martian meteorite was the detection of the 1300 cm−1 band using Raman. The main reason for this peculiarity is that band is characterized in meteorites as a D band. Generally, this band is attributed to structural defects and the disordering of carbon. However, care should be taken when interpreting Raman spectra around 1300 cm−1 and FTIR spectra 2950–2840 cm−1 of the sample from oxidizing environments such as Mars. Misconceptions can occur during the interpretations of the bands, and this can lead to incorrect identification. Thus, an analysis of the mentioned peaks, such as chemical and mineralogical assignments, will be provided and suggested in order to compare the results that mentioned the presence of organic compounds in the Zagami meteorite.

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Grossman, Mark I. "Smithson Tennant: meteorites and the final trip to France". Notes and Records of the Royal Society 61, n.º 3 (13 de julho de 2007): 265–83. http://dx.doi.org/10.1098/rsnr.2007.0188.

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Smithson Tennant is known mainly for his discovery of osmium and iridium. This paper details Tennant's involvement with meteorites, which has received little attention by his biographers, and provides new information about his final stay in Paris. Tennant reported his analysis of the Cape of Good Hope meteorite in 1806 and received a sample of the Bendego meteorite in 1811 that was subsequently analysed by Wollaston. During Tennant's final trip to France, which began in September 1814, Berthollet presented a sample of the Limerick meteorite that he received from Tennant to the French Institute. Tennant visited Delamétherie, and an unpublished letter acquired by the author shows that he met the explorer and scientist Alexander von Humboldt. The Limerick meteorite was discussed with Delamétherie and probably with Humboldt. Evidence suggests that Tennant met the painter François Gérard and the scientists Biot, Arago, Gay-Lussac and Cuvier. The Limerick meteorite specimen that Tennant gave to Berthollet is probably Muséum National d'Histoire Naturelle sample MNHN-35, whose donor is unknown. Tennant was the first to be quoted in the scientific literature about the Limerick meteorite—more than three years before the scientist William Higgins published his account of the meteorite shower.

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Naraoka, Hashiguchi, Sato e Hamase. "New Applications of High-Resolution Analytical Methods to Study Trace Organic Compounds in Extraterrestrial Materials". Life 9, n.º 3 (26 de julho de 2019): 62. http://dx.doi.org/10.3390/life9030062.

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Organic compounds are present as complex mixtures in extraterrestrial materials including meteorites, which may have played important roles in the origin of life on the primitive Earth. However, the distribution and formation mechanisms of meteoritic organic compounds are not well understood, because conventional analytical methods have limited resolution and sensitivity to resolve their molecular complexity. In this study, advanced instrumental development and analyses are proposed in order to study the trace organic compounds of extraterrestrial materials: (1) a clean room environment to avoid organic contamination during analysis; (2) high-mass-resolution analysis (up to ~150,000 m/m) coupled with high-performance liquid chromatography (HPLC) in order to determine the elemental composition using exact mass for inferring the chemical structure; (3) superior chromatographic separation using a two-dimensional system in order to determine the structural and optical isomers of amino acids; and (4) in situ organic compound analysis and molecular imaging of the sample surface. This approach revealed a higher complexity of organic compounds with a heterogeneous distribution in meteorites. These new methods can be applied to study the chemical evolution of meteoritic organic compounds as well as the molecular occurrence in very-low-mass extraterrestrial materials such as asteroid-returned samples.

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Smith, Joseph P., Frank C. Smith e Karl S. Booksh. "Multivariate Curve Resolution–Alternating Least Squares (MCR-ALS) with Raman Imaging Applied to Lunar Meteorites". Applied Spectroscopy 72, n.º 3 (11 de agosto de 2017): 404–19. http://dx.doi.org/10.1177/0003702817721715.

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Lunar meteorites provide a more random sampling of the surface of the Moon than do the returned lunar samples, and they provide valuable information to help estimate the chemical composition of the lunar crust, the lunar mantle, and the bulk Moon. As of July 2014, ∼96 lunar meteorites had been documented and ten of these are unbrecciated mare basalts. Using Raman imaging with multivariate curve resolution–alternating least squares (MCR-ALS), we investigated portions of polished thin sections of paired, unbrecciated, mare-basalt lunar meteorites that had been collected from the LaPaz Icefield (LAP) of Antarctica—LAP 02205 and LAP 04841. Polarized light microscopy displays that both meteorites are heterogeneous and consist of polydispersed sized and shaped particles of varying chemical composition. For two distinct probed areas within each meteorite, the individual chemical species and associated chemical maps were elucidated using MCR-ALS applied to Raman hyperspectral images. For LAP 02205, spatially and spectrally resolved clinopyroxene, ilmenite, substrate-adhesive epoxy, and diamond polish were observed within the probed areas. Similarly, for LAP 04841, spatially resolved chemical images with corresponding resolved Raman spectra of clinopyroxene, troilite, a high-temperature polymorph of anorthite, substrate-adhesive epoxy, and diamond polish were generated. In both LAP 02205 and LAP 04841, substrate-adhesive epoxy and diamond polish were more readily observed within fractures/veinlet features. Spectrally diverse clinopyroxenes were resolved in LAP 04841. Factors that allow these resolved clinopyroxenes to be differentiated include crystal orientation, spatially distinct chemical zoning of pyroxene crystals, and/or chemical and molecular composition. The minerals identified using this analytical methodology—clinopyroxene, anorthite, ilmenite, and troilite—are consistent with the results of previous studies of the two meteorites using electron microprobe analysis. To our knowledge, this is the first report of MCR-ALS with Raman imaging used for the investigation of both lunar and other types of meteorites. We have demonstrated the use of multivariate analysis methods, namely MCR-ALS, with Raman imaging to investigate heterogeneous lunar meteorites. Our analytical methodology can be used to elucidate the chemical, molecular, and structural characteristics of phases in a host of complex, heterogeneous geological, geochemical, and extraterrestrial materials.

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Kowalik, J. A. "Convergent-beam diffraction and x-ray analysis of the lamellar structure in the Dayton meteorite". Proceedings, annual meeting, Electron Microscopy Society of America 44 (agosto de 1986): 698–99. http://dx.doi.org/10.1017/s0424820100144863.

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The phase transformation resulting in a lamellar morphology found in the iron meteorite Dayton (18 wt% Ni-Fe) has been investigated using analytical electron microscopy (AEM). The transformation is unique to the Dayton meteorite since in other iron meteorites of similar composition and cooling history, only the classical Widmanstätten structure is present consisting of ferritic (α-BCC) plates precipitating on the (111) planes of the prior austenite (γ-FCC). However, in some areas of Dayton, the structure changes from the classical Widmanstätten pattern to a lamellar morphology. As a first step in understanding the mechanisms of the precipitation reactions, convergent beam electron diffraction (CBED) and x-ray energy dispersive spectrometry (XEDS) have been used to examine the crystallographic orientation and composition of the α/γ interface of the Widmanstätten and lamellar morphology.

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SATO, Masahiro, Ritsu HIROHARA e Muneyuki IMAFUKU. "Texture analysis for the iron meteorites". Proceedings of Conference of Kanto Branch 2017.23 (2017): 903. http://dx.doi.org/10.1299/jsmekanto.2017.23.903.

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Shirai, Naoki, Yoshihiro Hidaka, Akira Yamaguchi, Shun Sekimoto, Mitsuru Ebihara e Hideyasu Kojima. "Neutron activation analysis of iron meteorites". Journal of Radioanalytical and Nuclear Chemistry 303, n.º 2 (5 de outubro de 2014): 1375–80. http://dx.doi.org/10.1007/s10967-014-3654-4.

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Zolensky, Michael E., Robert J. Bodnar, Hisayoshi Yurimoto, Shoichi Itoh, Marc Fries, Andrew Steele, Queenie H. S. Chan, Akira Tsuchiyama, Yoko Kebukawa e Motoo Ito. "The search for and analysis of direct samples of early Solar System aqueous fluids". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375, n.º 2094 (17 de abril de 2017): 20150386. http://dx.doi.org/10.1098/rsta.2015.0386.

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We describe the current state of the search for direct, surviving samples of early, inner Solar System fluids—fluid inclusions in meteorites. Meteoritic aqueous fluid inclusions are not rare, but they are very tiny and their characterization is at the state of the art for most analytical techniques. Meteoritic fluid inclusions offer us a unique opportunity to study early Solar System brines in the laboratory. Inclusion-by-inclusion analyses of the trapped fluids in carefully selected samples will, in the immediate future, provide us detailed information on the evolution of fluids as they interacted with anhydrous solid materials. Thus, real data can replace calculated fluid compositions in thermochemical calculations of the evolution of water and aqueous reactions in comets, asteroids, moons and the terrestrial planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.

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Cocean, Alexandru, Cristina Postolachi, Georgiana Cocean, Georgiana Bulai, Bogdanel Silvestru Munteanu, Nicanor Cimpoesu, Iuliana Cocean e Silviu Gurlui. "The Origin and Physico-Chemical Properties of Some Unusual Earth Rock Fragments". Applied Sciences 12, n.º 3 (19 de janeiro de 2022): 983. http://dx.doi.org/10.3390/app12030983.

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In this paper, several researches were undertaken related to a violent phenomenon, characterized by a sonic boom, felt on an area of at least 500 km2, shortly followed by the fall of rock fragments that were then recovered from the ground. These presented different appearance characteristics from those of the materials and rocks specific to the respective area. Spectroscopic and petrographic analyses were performed to identify the composition, morphological and crystallinity characteristics in order to elucidate the nature of the collected rock samples. Using FTIR spectroscopy functional groups, as those reported in the literature for Murchison, Bells and Allende, carbonaceous chondrite meteorites were identified. The fragments evidenced topography and morphology that can be assigned to the chondrules and chondrites of carbonaceous meteorites (CMs). The material in the fragments proved to be as insoluble organic material (IOM), being insoluble in water and organic solvents. Its crystalline structure was also evidenced by XRD analysis and FTIR spectrum. These physico-chemical properties, in relation to the sonic boom perceived in the area from where they were collected, indicate the spatial origin of the fragments of rock as possible meteorite fragments.

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Nachit, Hassane, Abderrahmane Ibhi, Mohamed En-nasiry, Vanni Moggi Cecchi, Giovanni Pratesi, Christopher D. K. Herd e Giorgio S. Senesi. "Minerochemical and Microtextural Study of the Ungrouped Iron Meteorite Oglat Sidi Ali, Eastern Highlands, Morocco, and Geomorphological Characterization of Its Strewnfield". Minerals 12, n.º 11 (20 de novembro de 2022): 1470. http://dx.doi.org/10.3390/min12111470.

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Fragments of a new iron meteorite were found in and collected from Oglat Sidi Ali, Maatarka region, Morocco, during a series of expeditions in the years 2013–2017. The physical characteristics of recovered fragments feature typical attributes of individual samples of a unique meteorite strewnfield that originated from an iron meteorite shower via the fragmentation of a single body that broke up in the lower atmosphere. The total recovered mass of the Oglat Sidi Ali meteorite fragments was estimated to amount to more than 800 kg spread across a NE–SW oriented, 20 km-long and 5 km-wide strewnfield. Geochemical and mineralogical data achieved on Oglat Sidi Ali fragments, as well as the analysis of its microstructures obtained using electron backscattered diffraction (EBSD), suggested it should be classified as an ungrouped iron meteorite. A comparison of this meteorite with other ungrouped iron meteorites, such as NWA 859 and NWA 11010, purchased between 2001 and 2016 in various cities of Northeast Morocco show apparently similar mineralogy, geochemistry and textural features, suggesting a common origin from a single extraterrestrial body.

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Williams, D. B., e J. I. Goldstein. "Electron Microscopy and Microanalysis of Metal Phases in Meteorites". Microscopy and Microanalysis 4, S2 (julho de 1998): 602–3. http://dx.doi.org/10.1017/s1431927600023138.

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Meteorites are remnants of the primordial material from which the solar system condensed. Most meteorites originated in the asteroid belt between Mars and Jupiter and fell to earth when their orbits were disturbed by collisions. Metal phases are present in all types of meteorites and are alloys of Fe and Ni containing S and P. The study of metal meteorites has yielded valuable information about the early thermal history of the solar system, since their heat treatment has been preserved in the microstructure and microchemistry of the meteorites and can be discerned by electron microscopy and microanalysis. A full understanding of the structure and chemistry of meteorites requires detailed knowledge of the Fe-Ni, Fe-Ni-S and Fe-Ni-P phase diagrams and determination of these diagrams has been carried out over more than three decades of electron-beam analysis by the authors.

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Arkadiy Vasil’evich, OVCHARENKO. "Geophysical search for fragments of the Sterlitamak meteorite". NEWS of the Ural State Mining University, n.º 2 (15 de junho de 2021): 123–33. http://dx.doi.org/10.21440/2307-2091-2021-2-123-133.

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Relevance is determined by the fact that meteorites are of great importance for the direct study of the substance of the Universe, therefore, when new meteorites fall, maximum efforts are made to detect them and study the conditions of the fall. The purpose of the work is to further study the meteorite crater and search for large fragments of the Sterlitamak meteorite not found at the first stage of study using geophysical methods. The story of the fall and searches for the main fragment of the Sterlitamak meteorite, which fell on August 17, 1990 at 23 h 25 min, on the field of the Sterlitamak state farm is described. When it fell, a crater with a diameter of 10 m and a depth of 4 m was formed. The fall was accompanied by a bright glow and thunderous rumbles. A glow was observed over the crater in the dark. A high-speed searching for the meteorite was organized by collecting meteorite debris around the crater. At the same time, a mine detector was used. The crater was excavated with an excavator to a depth of 18–20 m. Fragments weighing 6.6; 3.06; 0.875; 0.363 kg were found. A year later, the main body weighing 315 kg was accidentally found in the dumps. Chemical analysis of the substance showed that it is an iron-nickel meteorite, 98% of the thickness are the minerals kamacite, tenite and schreibersite. Results. In 2014–2015, the authors carried out magnetic surveying around the crater and on the ice of the lake, which was formed at the excavation site, in order to search for fragments of the meteorite, which were probably missed at the initial stage. Maps of the magnetic field and terrain of the crater are given. Magnetic anomalies are identified, which are presumably associated with new fragments of the meteorite. The probable depths of the meteorite fragments are 2–4 m. In-depth sections of the magnetization for these anomalies obtained by the method of magnetic tomography, are given, as well as the results of a surface survey of the dump area using a metal detector. Weakly magnetic samples were found containing sprayed metal and metal balls with a diameter of 0.5–1.0 mm. These samples originally formed a zone of impact metamorphism, which was destroyed by excavation operations. It is shown that the territory is promising for searching for new large fragments of the meteorite and studying the processes of impact metamorphism. It is planned to further study the crater by means of electrical exploration and GPR sounding.

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Nascimento-Dias, Bruno Leonardo do, Maria Beatriz Barbosa de Andrade e Zélia Maria da Costa Ludwig. "Analysing the astrobiological aspects through the comparison of pyroxenes detected in meteorites and Martian environments". International Journal of Astrobiology 18, n.º 6 (23 de abril de 2019): 547–51. http://dx.doi.org/10.1017/s1473550419000041.

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AbstractAlthough pyroxenes are found abundantly in igneous rocks, this mineral group stands out for being one of the ferromagnesian mineral groups that constitute rocks of several different compositions. Hence, the purpose of this work is to demonstrate how these minerals may be relevant to Astrobiology. Essentially, through geochemical analyses of pyroxenes detected in Martian meteorites, it may be possible to find evidence of the existence of water in hydrothermal flows located in deep regions below the Martian surface. To this extent, it is also very important to highlight the whole collection of observational data from Mars, in which it is possible to notice that pyroxenes are found in a wide variety of geological environments. Therefore, based on Martian surface observations, meteorite analysis and experimental data, it is conceivable that, given the appropriate conditions, pyroxenes might be related to the formation and release of water molecules in the Martian environment.

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Ruf, Alexander, Pauline Poinot, Claude Geffroy, Louis Le Sergeant d’Hendecourt e Gregoire Danger. "Data-Driven UPLC-Orbitrap MS Analysis in Astrochemistry". Life 9, n.º 2 (2 de maio de 2019): 35. http://dx.doi.org/10.3390/life9020035.

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Meteorites have been found to be rich and highly diverse in organic compounds. Next to previous direct infusion high resolution mass spectrometry experiments (DI-HR-MS), we present here data-driven strategies to evaluate UPLC-Orbitrap MS analyses. This allows a comprehensive mining of structural isomers extending the level of information on the molecular diversity in astrochemical materials. As a proof-of-concept study, Murchison and Allende meteorites were analyzed. Both, global organic fingerprint and specific isomer analyses are discussed. Up to 31 different isomers per molecular composition are present in Murchison suggesting the presence of ≈440,000 different compounds detected therein. By means of this time-resolving high resolution mass spectrometric method, we go one step further toward the characterization of chemical structures within complex extraterrestrial mixtures, enabling a better understanding of organic chemical evolution, from interstellar ices toward small bodies in the Solar System.

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Musa, Maya, Riccardo Rossini, Daniela Di Martino, Maria Pia Riccardi, Massimiliano Clemenza e Giuseppe Gorini. "Combining Micro-Raman Spectroscopy and Scanning Electron Microscopy Mapping: A Stony Meteorite Study". Materials 14, n.º 24 (10 de dezembro de 2021): 7585. http://dx.doi.org/10.3390/ma14247585.

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Meteorite characterisation represents a privileged and unique opportunity to increase our knowledge about the materials composing the Universe and, particularly, the Proto Solar System. Moreover, meteorites studies evolve contextually with the development of analytical technologies. In the present paper, the results from an unclassified stony meteorite (chondrite) characterisation have been reported on the basis of the innovative analytical protocol presented here. Advanced Mapping by micro-Raman Spectroscopy and Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy have been combined to disclose molecular and elemental features on the same regions sample at a micrometric resolution. Thanks to their non-destructive properties, the mapping tools of both instruments have been applied to single chondrules analysis and the best match between the mineralogical information and the chemical composition has been obtained. This combined approach proved to be highly suitable in disclosing the crystallinity features of the phases, with in-depth spatial and morphological details too.

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WANG, MING-SHENG, JENNIFER A. MOKOS e MICHAEL E. LIPSCHUTZ. "Martian meteorites: Volatile trace elements and cluster analysis". Meteoritics & Planetary Science 33, n.º 4 (julho de 1998): 671–75. http://dx.doi.org/10.1111/j.1945-5100.1998.tb01672.x.

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Skulteti, A., A. Kereszturi, Zs Kereszty, B. Pal, M. Szabo e F. Cipriani. "Role of spectral resolution for infrared asteroid compositional analysis using meteorite spectra". Monthly Notices of the Royal Astronomical Society 496, n.º 1 (28 de maio de 2020): 689–94. http://dx.doi.org/10.1093/mnras/staa1475.

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ABSTRACT In this work the potential mineral identification of meteorites is analysed for the mid-infrared range, to evaluate observational possibilities for future missions targeting small body surfaces. Three carbonaceous and three ordinary chondrite meteorites are examined by a diffuse reflection (DRIFT) instrument, and the presence of principal minerals is confirmed by a powder diffraction method as well. The possibilities and constraints of mineral identifications in the mid-infrared are simulated by artificially degrading the spectral resolution. Our research shows that for the definite identification of principal mineral bands, a spectral resolution ≤10 cm−1 (≤0.15 μm) is needed. At 20–100 cm−1 (0.3–1.5 μm) resolution the identification of these minerals is uncertain, and with a resolution >100 cm−1, it is almost impossible.

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Zamora, L. Lahuerta, P. Alemán López, G. M. Antón Fos, R. Martín Algarra, A. M. Mellado Romero e J. Martínez Calatayud. "Quantitative colorimetric-imaging analysis of nickel in iron meteorites". Talanta 83, n.º 5 (fevereiro de 2011): 1575–79. http://dx.doi.org/10.1016/j.talanta.2010.11.058.

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Opeil, C. P., G. J. Consolmagno e D. T. Britt. "The thermal conductivity of meteorites: New measurements and analysis". Icarus 208, n.º 1 (julho de 2010): 449–54. http://dx.doi.org/10.1016/j.icarus.2010.01.021.

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Chernonozhkin, Stepan M., Steven Goderis, Stephen Bauters, Bart Vekemans, Laszlo Vincze, Philippe Claeys e Frank Vanhaecke. "Evaluation of pneumatic nebulization and ns-laser ablation ICP-MS for bulk elemental analysis and 2-dimensional element mapping of iron meteorites". J. Anal. At. Spectrom. 29, n.º 6 (2014): 1001–16. http://dx.doi.org/10.1039/c3ja50387a.

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Pohl, Leos, e Daniel T. Britt. "Strengths of meteorites—An overview and analysis of available data". Meteoritics & Planetary Science 55, n.º 4 (abril de 2020): 962–87. http://dx.doi.org/10.1111/maps.13449.

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Carpenter, Paul, Anthony Irving, Chris Yen e Bradley Jolliff. "Quantitative EPMA Compositional Mapping and Cluster Analysis Applied to Meteorites". Microscopy and Microanalysis 26, S2 (30 de julho de 2020): 760–62. http://dx.doi.org/10.1017/s1431927620015755.

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Bondar, Yu V., e V. P. Perelygin. "Fission-track analysis of meteorites: Dating of the Marjalahti pallasite". Radiation Measurements 40, n.º 2-6 (novembro de 2005): 522–27. http://dx.doi.org/10.1016/j.radmeas.2005.06.013.

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Vasilescu, Angela, B. Constantinescu, Roxana Bugoi, D. Ceccato, D. Grambole e F. Herrmann. "Micro-elemental analysis of some Transylvanian meteorites and lunar samples". Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 267, n.º 12-13 (junho de 2009): 2233–35. http://dx.doi.org/10.1016/j.nimb.2009.03.017.

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Noll, K., M. Döbeli e U. Krähenbühl. "Fluorine profiles in Antarctic meteorites by nuclear reaction analysis (NRA)". Fresenius' Journal of Analytical Chemistry 361, n.º 6-7 (3 de agosto de 1998): 713–15. http://dx.doi.org/10.1007/s002160051002.

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Loylip, T., e S. Wannawichian. "Elemental composition analysis of stony meteorites discovered in Phitsanulok, Thailand". Journal of Physics: Conference Series 901 (setembro de 2017): 012005. http://dx.doi.org/10.1088/1742-6596/901/1/012005.

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Holdship, Phil, Pierre Bonnand, David Price e Paul Watson. "Micro flow injection ICP-MS analysis of high matrix samples: an investigation of its capability to measure trace elements in iron meteorites". Journal of Analytical Atomic Spectrometry 33, n.º 11 (2018): 1941–53. http://dx.doi.org/10.1039/c8ja00162f.

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The coupling of a micro-flow injection sample introduction system to a highly versatile quadrupole ICP-MS (FI-ICP-MS) has been demonstrated to achieve accurate and precise trace element measurements for several iron meteorites.

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Pechersky, D. M., e G. P. Markov. "The history and state-of-the-art of the studies of native iron in terrestrial and extraterrestrial rocks". Физика Земли, n.º 2 (6 de abril de 2019): 111–22. http://dx.doi.org/10.31857/s0002-333720192111-122.

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A brief review on the history of studying native iron in terrestrial rocks and meteorites is presented. The synthesis and systematization of extensive data on the distribution, composition, and grain size of metal iron particles in sediments, other terrestrial rocks, and meteorites obtained by thermomagnetic analysis with heating to 800 °C combined with microprobe analysis are described. The studies show that ironparticles in all the studied sediments typically have extraterrestrial origin. Based on the statistical analysis of the thermomagnetic data, a number of indications (statistical regularities) are proposed testifying to the overwhelmingly extraterrestrial origin of iron particles in sediments. The similarity of the formation conditions of terrestrial and extraterrestrial metal iron particles makes it possible to suggest a petromagnetic scheme for the structure of planets based on the distribution of metal iron in them.

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А.К., Терентьева,, e Барабанов, С.И. "Meteorite Križevci (Croatia) and meteoroid stream Cancrid". Научные труды Института астрономии РАН, n.º 4 (16 de dezembro de 2022): 241–43. http://dx.doi.org/10.51194/inasan.2022.7.4.004.

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На основании анализа более 500 орбит метеороидных и болидных роев по опубликованным каталогам нами была установлена связь метеорита Križevci, порожденного болидом 4 февраля 2011 г. над Хорватией [1] с метеороидным роем Канкрид (No. 166 (а), [2, 3]). Известный критерий Саутворта-Хокинса дает величину D SH = 0.128, которая является вполне приемлемой для достаточно хорошего согласия орбит метеорита и роя. Динамический параметр Тиссерана указывает на астероидное происхождение роя и метеорита. Таким образом, выявлен еще один метеоритообразующий рой, который дополняет список 14 метеоритообразующих роев, найденных нами ранее [4]. Эти рои имеют важное значение с точки зрения потенциальной опасности при встрече их с Землей. В работе приводится краткая информация о таком редком явлении, которое названо А. Брезиной [5] «цепным падением» метеоритов. Based on the analysis of more than 500 orbits of meteoroid and reball streams according to published catalogs, we established the connection of the Križevci meteorite generated by the bolide on February 4, 2011 over Croatia [1] with a meteoroid stream Cancrid (No. 166 (a), [2, 3]). The well-known Southworth-Hawkins criterion gives a value of D SH = 0.128, which is quite acceptable for a fairly good agreement of the orbits of the meteorite and the stream. The dynamic parameter of Tisserand indicates the asteroid origin of the stream and the meteorite. Thus, this is yet another meteorite-forming stream that complements the list of 14 meteorite-forming streams that we found earlier [4]. These streams have an signi cance in terms of potential danger when they approach the Earth. The paper provides brief information about such a rare phenomenon, which is called the “chain fall” of meteorites by A. Brezina [5].

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Hamilton, Victoria E., Christopher W. Haberle e Thomas G. Mayerhöfer. "Effects of small crystallite size on the thermal infrared (vibrational) spectra of minerals". American Mineralogist 105, n.º 11 (1 de novembro de 2020): 1756–60. http://dx.doi.org/10.2138/am-2020-7602.

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Abstract The thermal infrared (TIR, or vibrational) emission spectra of a suite of synthetic Mg-Fe olivines exhibit notable differences from their natural igneous counterparts in terms of their band shapes, relative depths, and reduced shifts in some band positions with Mg-Fe solid solution. Comparable reflectance spectra acquired from olivine-dominated matrices and fusion crusts of some carbonaceous chondrite meteorites exhibit similar deviations. Here we show that these unusual spectral characteristics are consistent with crystallite sizes much smaller than the resolution limit of infrared light. We hypothesize that these small crystallites denote abbreviated crystal growth and also may be linked to the size of nucleation sites. Other silicates and non-silicates, such as carbonates, exhibit similar spectral behaviors. Because the spectra of mineral separates are commonly used in the modeling and analysis of comparable bulk rock, meteorite, and remote sensing data, understanding these spectral variations is important to correctly identifying the minerals and interpreting the origin and/or secondary processing histories of natural materials.

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D'Orazio, Massimo, e Luigi Folco. "Chemical Analysis of Iron Meteorites by Inductively Coupled Plasma-Mass Spectrometry". Geostandards and Geoanalytical Research 27, n.º 3 (novembro de 2003): 215–25. http://dx.doi.org/10.1111/j.1751-908x.2003.tb00723.x.

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Miyamoto, Hideaki, Takafumi Niihara, Takeshi Kuritani, Peng K. Hong, James M. Dohm e Seiji Sugita. "Cluster analysis on the bulk elemental compositions of Antarctic stony meteorites". Meteoritics & Planetary Science 51, n.º 5 (10 de março de 2016): 906–19. http://dx.doi.org/10.1111/maps.12634.

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Stefanik, Milan, Martin Cesnek, Lubomir Sklenka, Tomas Kmjec e Marcel Miglierini. "Neutron activation analysis of meteorites at the VR-1 training reactor". Radiation Physics and Chemistry 171 (junho de 2020): 108675. http://dx.doi.org/10.1016/j.radphyschem.2019.108675.

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Höfler, S., W. Schäfer e G. Will. "Neutron diffraction pole figure measurements for the microstructure analysis of meteorites". Physica B: Condensed Matter 156-157 (janeiro de 1989): 675–77. http://dx.doi.org/10.1016/0921-4526(89)90760-6.

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Povinec, Pavel P., Ivan Sýkora, Andrej Kováčik e Christian Koeberl. "High-sensitivity HPGe gamma-spectrometry analysis of radionuclides in Martian meteorites". Journal of Radioanalytical and Nuclear Chemistry 307, n.º 3 (15 de outubro de 2015): 2403–7. http://dx.doi.org/10.1007/s10967-015-4523-5.

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Madiedo, José M., José L. Ortiz, Josep M. Trigo-Rodríguez, Joan Dergham, Alberto J. Castro-Tirado, Jesús Cabrera-Caño e Pep Pujols. "Analysis of bright Taurid fireballs and their ability to produce meteorites". Icarus 231 (março de 2014): 356–64. http://dx.doi.org/10.1016/j.icarus.2013.12.025.

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Paul, Rick L., e Michael E. Lipschutz. "Labile Trace Elements in Some Antarctic Carbonaceous Chondrites: Antarctic and Non-Antarctic Meteorite Comparisons". Zeitschrift für Naturforschung A 44, n.º 10 (1 de outubro de 1989): 979–87. http://dx.doi.org/10.1515/zna-1989-1010.

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Abstract We report data for Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Sb, Se, Te, TI, U and Zn determined by radiochemical neutron activation analysis in consortium samples of Belgica (B) 7904, Yamato (Y) 82042, Yamato 82162 and Yamato 86720 carbonaceous chondrites. These trace elements cover a wide volatility/mobility range and give unique information on thermal histories of meteorites. The results indicate the unique nature of these carbonaceous chondrites. Y-82042 proves to have the volatile element pattern of a C2 ( ≡CM) chondrite and the petrologic characteristics of a CI (n≡CI) chondrite. These must be primary nebular condensation/accretion features, unaffected by post-accretionary processes. The other three meteorites were thermally metamorphosed in ≧2 parent regions over the 600-700 °C range, at relative temperatures B-7904 < Y-82162< Y-86720. Before heating, B-7904 and Y-86720 had C2-levels of volatile elements: Y-82162 had uniquely high volatile element concentrations, at about CI-levels. The data require a new classification scheme for such chondrites. Belgica 7904 and Y-82162 and -86720 seem to be derived from one or more thermally altered carbonaceous asteroids, and their spectral characteristics should be compared with those of B-, F-, G- or T-asteroids. These results indicate substantial differences in the thermal histories of Antarctic and non-Antarctic CI and C2 chondrite populations. In reviewing all that is known about the Antarctic and non-Antarctic meteorite populations, the overwhelming weight of evidence supports the view that these populations sample different extraterrestrial source materials, differing in thermal histories. It may be that over the extended collecting period of the Antarctic ice sheet, it has sampled a considerably greater proportion of near-Earth asteroids than do current falls.

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Greenough, John D., e Avee Ya’acoby. "A comparative geochemical study of Mars and Earth basalt petrogenesis". Canadian Journal of Earth Sciences 50, n.º 1 (janeiro de 2013): 78–93. http://dx.doi.org/10.1139/cjes-2012-0023.

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Geochemical data, from the Mars Meteorite Compendium web site, for 13 basaltic meteorites, possibly from only four localities on Mars, are used to study Martian petrogenetic processes. To achieve this goal, an exploratory data analysis technique, multidimensional scaling (MDS), is used to quantitatively assess the relative behavior (measured with correlation coefficients) of 160 incompatible element ratios involving 25 “trace” elements. The ratios behave as in Earth basalts, suggesting that relative element incompatibility is similar in both planets. Because mineralogy controls incompatibility, the mineralogy of Earth and Mars mantles appears similar. In addition, results suggest that ratios involving elements with highly different incompatibility (e.g., La/Yb) are dominantly controlled by % melting. Plots of SiO2 (pressure proxy; decreases with increasing pressure) versus La/Yb and Nb/Y (decrease as melting increases) imply that Mars basalts, like Earth tholeiites, reflect high percentages of melting, but opposite to Earth, % melting appears to increase with increasing pressure. The moderately correlated, positive, SiO2–La/Yb Mars relationship parallels highly correlated Lunar KREEP data and contrasts with Earth’s negative correlation. The positive relationships may reflect restricted mantle convection in some (Mars and the Moon are smaller) planetary bodies. Using similarly incompatible element ratios that are sensitive to source composition, to compare Mars and Earth with MDS, Mars sources most resemble depleted Earth mantle. Additionally, these ratios group Mars sources into enriched, depleted, and intermediate types. The groupings are the same as those suggested by isotopes, and we conclude that trace element data support the hypothesis that chemical variation in Mars may reflect crystallization of a Mars magma ocean. The natural patterns in ratios and samples revealed using MDS, which has no a priori information about relationships, support integrity of the geochemical data set, despite potential shortcomings such as small sample sizes, alteration, and weathering. However, whether the meteorites are representative of Mars as a whole is unknown.

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Bernatowicz, Thomas J. "TEM studies of circumstellar dust". Proceedings, annual meeting, Electron Microscopy Society of America 50, n.º 2 (agosto de 1992): 1714–15. http://dx.doi.org/10.1017/s0424820100133205.

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In recent years the development of special chemical separation techniques has permitted the isolation of material from primitive meteorites that can be unambiguously identified as pre-solar grains-that is, solids that condensed in the atmospheres of ancient stars and later became incorporated into the cloud of gas and dust which gave rise to our solar system. This identification is made possible in part by development of sophisticated mass spectrometry techniques for the analysis of ensembles of these grains and in part by ion microprobe techniques for determining the isotopic structures in single micron-sized grains. In particular, meteoritic grains which have isotopic compositions radically different from the solar system average can be assigned a pre-solar origin. In some cases, plausible astrophysical sites can be identified: for example, isotopic structures of Kr, Xe, Ba, and Nd in some grains resemble those expected to be produced by s-process nucleosynthesis in asymptotic giant branch (AGB) stars.

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