The Tucson ungrouped iron meteorite and its relationship to chondrites
2010; Wiley; Volume: 45; Issue: 12 Linguagem: Inglês
10.1111/j.1945-5100.2010.01134.x
ISSN1945-5100
AutoresG. Kurat, M. E. Varela, E. Zinner, F. Brandstätter,
Tópico(s)Isotope Analysis in Ecology
ResumoMeteoritics & Planetary ScienceVolume 45, Issue 12 p. 1982-2006 Free Access The Tucson ungrouped iron meteorite and its relationship to chondrites G. KURAT, G. KURAT Department of Lithospheric Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria Mineralogisch-Petrographische Abteilung, Naturhistorisches Museum, Burgring 7, 1010 Wien, Austria Deceased.Search for more papers by this authorM. E. VARELA, Corresponding Author M. E. VARELA Instituto de Ciencias Astronómicas de la Tierra y del Espacio (ICATE), Av. España 1512 Sur, J5402DSP San Juan, Argentina Corresponding author. E-mail: [email protected]Search for more papers by this authorE. ZINNER, E. ZINNER Laboratory for Space Sciences and the Physics Department, Washington University, St. Louis, Missouri 63130, USASearch for more papers by this authorF. BRANDSTÄTTER, F. BRANDSTÄTTER Mineralogisch-Petrographische Abteilung, Naturhistorisches Museum, Burgring 7, 1010 Wien, AustriaSearch for more papers by this author G. KURAT, G. KURAT Department of Lithospheric Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria Mineralogisch-Petrographische Abteilung, Naturhistorisches Museum, Burgring 7, 1010 Wien, Austria Deceased.Search for more papers by this authorM. E. VARELA, Corresponding Author M. E. VARELA Instituto de Ciencias Astronómicas de la Tierra y del Espacio (ICATE), Av. España 1512 Sur, J5402DSP San Juan, Argentina Corresponding author. E-mail: [email protected]Search for more papers by this authorE. ZINNER, E. ZINNER Laboratory for Space Sciences and the Physics Department, Washington University, St. Louis, Missouri 63130, USASearch for more papers by this authorF. BRANDSTÄTTER, F. BRANDSTÄTTER Mineralogisch-Petrographische Abteilung, Naturhistorisches Museum, Burgring 7, 1010 Wien, AustriaSearch for more papers by this author First published: 06 January 2011 https://doi.org/10.1111/j.1945-5100.2010.01134.xCitations: 4 AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract Abstract– Tucson is an enigmatic ataxitic iron meteorite, an assemblage of reduced silicates embedded in Fe-Ni metal with dissolved Si and Cr. Both, silicates and metal, contain a record of formation at high temperature (∼1800 K) and fast cooling. The latter resulted in the preservation of abundant glasses, Al-rich pyroxenes, brezinaite, and fine-grained metal. Our chemical and petrographic studies of all phases (minerals and glasses) indicate that they have a nebular rather than an igneous origin and give support to a chondritic connection as suggested by Prinz et al. (1987). All silicate phases in Tucson apparently grew from a liquid that had refractory trace elements at approximately 6–20 × CI abundances with nonfractionated (solar) pattern, except for Sc, which was depleted (∼1 × CI). Metal seems to have precipitated before and throughout silicate aggregate formation, allowing preservation of all evolutionary steps of the silicates by separating them from the environment. In contrast to most chondrites, Tucson documents coprecipitation of metal and silicates from the solar nebula gas and precipitation of metal before silicates—in accordance with theoretical condensation calculations for high-pressure solar nebula gas. We suggest that Tucson is the most metal-rich and volatile-element-poor member of the CR chondrite clan. Introduction Tucson is a unique ataxitic iron meteorite with about 8 vol% silicates (mainly olivine) arranged in subparallel flow-like structures (Buchwald 1975). The high Si (0.8 wt%) and the very low Ge content of the metal (Wai and Wasson 1969) make Tucson distinctive among the iron meteorites with silicate inclusions (Wasson 1970). Silicate inclusions in Tucson, first reported by Smith (1855), have a remarkably reduced state (Cohen 1905), are depleted in volatile elements, and have on average approximately chondritic refractory lithophile element abundances (Wänke et al. 1983). The low iron content of the silicates, the high content of silicon in the metal, and the chalcophile behavior of vanadium, among other features, led Bunch and Fuchs (1969) to point out that Tucson shows similarities with enstatite chondrites and achondrites. Nehru et al. (1982) also explored the possible relationship between Tucson and the enstatite meteorites. On the other hand, Prinz et al. (1987) concluded that Tucson silicates have isotopic and chemical similarities with constituents from carbonaceous chondrites such as Bencubbin, Kakangari, and Renazzo. Here, we report the result of a compositional (major and trace element) study of the phases constituting the silicate inclusions of this meteorite. We examined their petrological relationships with each other and with other meteoritic rocks and discuss the possible ways in which Tucson silicates could have formed. Preliminary results were presented at the Lunar and Planetary Science Conference in Houston, Texas, and the Meteoritical Society Meeting in Nancy, France (Varela et al. 2008, 2009, 2010). Analytical Techniques and Samples Silicate inclusions were studied in the thin section L3951 and the thick polished section Tucson B (NHM, Vienna). The nonmetallic phases in the Tucson iron were studied with an optical microscope and a scanning electron microscope. Major element chemical compositions were obtained with a JEOL 6400 analytical scanning electron microscope and ARL-SEMQ and CAMECA SX100 electron microprobes (EMP) (NHM, Vienna; Department of Lithospheric Science, University of Vienna; and ICATE, San Juan, Argentina). Microprobe analyses were performed at 15 kV (silicates) and 20 kV (metal and sulfide) acceleration potential and 15 nA sample current. Trace element analyses of silicates and sulfides were made with the Cameca IMS 3F ion microprobes at Washington University (St. Louis) and Max-Planck-Institut für Chemie (Mainz), following a modified procedure of Zinner and Crozaz (1986). Results Petrography of Silicate Inclusions and Sulfides The ungrouped iron Tucson contains about 8 vol% silicate inclusions (Buchwald 1975), which are arranged in a way that is reminiscent of flow structures (Bunch and Fuchs 1969; Miyake and Goldstein 1974; Buchwald 1975). They cover metal nodules and are arranged along huge bent plates (Figs. 1a and 1b). Round aggregation structures of metal nodules and silicate inclusion are dominant in the cut surface of sample A 726 (Fig. 1a) from the Naturhistorisches Museum in Vienna, and are also abundant in other samples, e.g., the Smithsonian Institution's sample U.S.N.M. no. 757 (see fig. 1801 in Buchwald 1975, p. 1237). Figure 1Open in figure viewerPowerPoint a) Polished surface of Tucson sample inventory no. A 726 (Naturhistorisches Museum, Vienna, 396 g) showing "flow" and aggregation structures. Centimeter-sized aggregates consist of metal nodules (arrows) decorated by silicates. Between the aggregates are situated elongated metal nodules and sheets of silicate aggregates (details in b). Length of sample is approximately 8 cm. b) Dark field optical picture (the sample is illuminated with light that is not collected by the objective lens) of the polished surface of sample M 8617 (Naturhistorisches Museum, Vienna) of the Tucson iron showing the arrangement of silicate inclusions (gray) around metal (black) nodules (left) and along planes. Note the range of sizes of silicate inclusions: small ones dominate the central streaky arrays and surfaces of metal nodules (left side), and large ones dominate the right upper region. Sample length is approximately 4 cm. Silicate inclusions range in size from <10 μm to about 1200 μm in sections L3951 and Tucson B (Figs. 2a–h). Inclusions of different shape and size occur in different plate aggregates. Large inclusions are elongated and are oriented parallel to the "flow" structure. There is also some correlation with inclusion size and the number of different phases present. Small silicate inclusions (∼40–∼100 μm)—which generally have round and smooth interfaces toward metal—are mostly composed of one (olivine) or two phases (olivine and glass; Figs. 2a–d). The single olivine inclusion in Fig. 2b has an inclusion which consists of glass, a metal globule, and a bubble. The two-phase silicate inclusions have mesostasis glass between olivines or surrounding the olivine (Figs. 2c and 2d). The olivine has crystal faces against glass but round interfaces with metal—as has previously been described by Nehru et al. (1982). Perfectly spherical glass-rich objects are rare and contain a single euhedral olivine with crystal faces against the glassy mesostasis (Fig. 2d). Other small inclusions consist of an olivine crystal which is completely covered by Ca-poor, Al-rich orthopyroxene and small amounts of aluminous Ca-rich pyroxene (Figs. 3a and 3b). Very common are also small inclusions made mainly of a single olivine crystal that is partly covered by Ca-poor, Al-rich orthopyroxene which forms intergrowths with brezinaite (symplectitic) and kamacite (inclusions; Figs. 3c and 3d). Figure 2Open in figure viewerPowerPoint a) Three large olivine-rich silicate inclusions (center, left, and upper left) and two-phase (olivine + glass) small ones (arrows). Inclusions are elongated in the direction of the general "flow" pattern. Optical image, crossed polarizers. b) BSE image of a small single olivine with an inclusion consisting of a metal globule, glass, and a bubble. c) Reflected light image of a small silicate inclusion in metal (M, gray), consisting of an olivine (Ol, light gray) and glass (white). Note the olivine crystal faces in contact with glass and the round interface in contact with metal. d) Reflected light image of a small silicate inclusion in metal (M, gray) consisting of an olivine crystal (Ol-B17, light gray) and glass (CMG-B17). Note the perfectly round shape of the inclusion and the perfectly developed crystal faces of the olivine. e) BSE image of upper end of central inclusion in (a) (stippled square) with clear mesostasis glass (CMG-T3) between olivines (Ol 2-T3 and Ol 1-T3). f) Olivine (Ol Host G.I.B#5) and glass inclusion G.I.B#5 with bubble; from lower end of central silicate inclusion in (a). Reflected light image. g) Reflected light image of olivines Ol B1-6 and Ol B1-7 with recrystallized mesostasis glass (RMG-B1) from a large silicate inclusion. Note small glass-rich silicate inclusion at upper left. h) Reflected light image (partly crossed polarizers) of glass inclusion G.I.1 with bubble in olivine (Ol Host G.I.1) of a large silicate inclusion. Figure 3Open in figure viewerPowerPoint a) BSE image of olivine single crystal (Ol) covered by Al-rich low-Ca pyroxene (Px) and Ca-rich clinopyroxene (Cpx) in metal (M). b) Map of Al distribution of area shown in (a). Note the highly variable Al content of the Ca-poor pyroxene. c) Optical image of a small silicate inclusion consisting of an olivine (Ol) and low-Ca pyroxene (Px)—brezinaite (S) symplectite. Note the well-developed brezinaite meniscus at the right surface of the inclusion (white arrow) and the rounded surfaces of all silicates against metal (M). d) Same object, image with partly crossed polarizers. e) Optical image (partly crossed polarizers) of small silicate inclusion consisting of olivine (Ol) and low-Ca pyroxene (Px)—brezinaite (S) symplectite in metal. Note the meniscus (white arrow) formed by brezinaite against metal (M) and the very small olivine-glass inclusion in metal at lower right. Large silicate inclusions are elongated multiphase rocks with serrated and/or smooth surfaces against metal. They consist of olivine and pyroxenes—as major phases—with minor glass or crystalline mesostasis, metal, and brezinaite (Figs. 4a and 4b). Olivine in these inclusions is always poikilitically included in or partly covered by Ca-poor, Al-rich orthopyroxene. The orthopyroxene also commonly forms symplectites with brezinaite and carries metal inclusions (Fig. 4c)—as in small inclusions. Very large inclusions (Fig. 4b) frequently consist of rounded olivines and angular clino-enstatites (Ca-poor and Al-poor), which are poikilitically enclosed by Ca-poor, Al-rich orthopyroxene. Poikilitic pyroxene has smooth interfaces with olivine, other pyroxenes, and anorthite. It has either smooth or serrated interfaces with metal and forms symplectitic intergrowths with brezinaite (Figs. 4a–c). Anorthite and Ca-rich, Al-rich pyroxene are scarce and the tiny grains are generally associated with Ca-poor, Al-rich orthopyroxene in contact with brezinaite (Figs. 4c and 4d). Figure 4Open in figure viewerPowerPoint a) Reflected light image of a multiphase silicate inclusion (enlargement from Fig. 2a, left) consisting of low-Ca pyroxene (right) and olivine (±glass, left), which are connected by symplectitic intergrowth of Al-rich pyroxene and brezinaite (left) and a complex intergrowth of Al-rich pyroxene and metal (right) (see details in c). The olivine-rich part has a smooth interface toward the metal but pyroxene has a complex one. b) Reflected light image of a large silicate inclusion consisting of rounded olivines and angular clino-enstatite (cracked) embedded in Al-rich orthopyroxene (smooth surface). The interface of Al-rich pyroxene toward metal is mostly smooth but also rugged in places. There is no glass or crystalline mesostasis exposed on this inclusion (see Profile 3, Table 1). c) BSE image of center portion of silicate inclusion shown in (a) (stippled square). Low-Ca, Al-rich pyroxene (Px), Ca-rich pyroxene (Cpx) and anorthite (An) forms symplectitic intergrowths with brezinaite (S, light gray) on the left and with kamacite on the right. Note the crystal faces shown by kamacite (M) enclosed in Al-rich orthopyroxene. The metal included in pyroxene has the shape of prismatic pyroxene crystals. d) BSE image of brezinaite (S) forming a meniscus toward the metal (M, white) and a symplectitic intergrowth with low-Ca pyroxene (Px), Ca-rich pyroxene (Cpx) and anorthite (An)—all on top of an olivine (Ol) of a large silicate inclusion (see Profiles 1 and 2, Table1). e) BSE image of olivine (Ol) from large silicate inclusion with brezinaite (S) meniscus toward metal (M). Brezinaite is the only sulfide present in Tucson (Buchwald 1975). It is always associated with pyroxenes and commonly forms symplectitic intergrowths with pyroxenes (±anorthite, Al-diopside) (Figs. 3c–e, 4c, and 4d). In contrast to the complex interfaces toward pyroxenes, brezinaite commonly has smooth menisci toward metal (Figs. 4d and 4e) and also smooth interfaces toward olivine (Fig. 3d). Glasses and mesostasis: Olivine in small and large silicate inclusions occasionally contains primary glass-bearing inclusions. These inclusions have sizes varying between 5 and 35 μm, rounded or subrounded shapes and are found in clusters (Figs. 2f and 2h) and as isolated inclusions (Fig. 2b). Most of them consist of clear glass and a shrinkage bubble. A few are multiphase inclusions that contain glass, metal, and a shrinkage bubble (Fig. 2b). All glasses of glass-bearing inclusions are clear without signs of devitrification. Mesostasis mainly is present between olivines or is enveloping olivine in small inclusions (Figs. 2e and 2g). It can either consist of clear glass (e.g., CMG [clear mesostasis glass]; Fig. 2e) or recrystallized glass (e.g., RMG [recrystallized mesostasis glass]; Fig. 2g). Olivine has crystal faces in contact with both mesostasis glasses (Figs. 2c–e and 2g). Major Element Phase Compositions Representative and averaged EMP analyses of the phases encountered in this study are given in Tables 1–2. Table 1. Major element composition of silicates in Tucson (in wt%). Coexisting phases Profile 1 Profile 2 Profile 3 An Al-Px Al-Px Ol An Al-Px Cpx Ol Ol Al-Px Px Al-Px Ol SiO2 42.7 49.1 48.7 42.6 42.7 48.5 50.7 42.5 41.9 54.6 57.8 52.7 41.9 TiO2 bdl 0.11 0.14 bdl bdl 0.20 0.22 bdl bdl 0.32 0.06 0.04 bdl Al2O3 36.1 17.0 12.9 0.07 34.9 17.7 7.3 0.07 0.04 6.3 0.6 9.2 0.04 Cr2O3 bdl 0.11 0.09 bdl 0.08 0.10 0.06 bdl bdl 0.11 0.07 0.11 bdl FeO 0.6 0.37 0.28 0.28 0.8 0.49 0.46 0.38 0.27 0.27 0.25 1.1 0.32 MnO bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl MgO 0.9 31.9 38.5 56.6 1.2 31.7 17.7 56.3 57.6 36.1 39.0 34.4 57.4 CaO 19.3 1.3 0.9 0.10 19.7 1.2 23.1 0.10 0.12 1.1 0.42 0.36 0.10 Na2O bdl bdl bdl bdl 0.03 bdl bdl bdl bdl bdl bdl bdl bdl K2O bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0.03 0.03 bdl Total 99.6 99.9 101.4 99.7 99.4 99.9 99.6 99.3 99.9 98.8 98.2 97.9 99.8 Coexisting pyroxenes Px2-B8 = 0.84*(6) Px1-B8 = 3.15*(6) Cpx B4*(2) Px-B4 = 9.43*(3) Px-B3 = 0.7*(3) Px-B3 = 9.8*(2) SiO2 59.3 57.5 49.3 53.5 59.2 52.8 TiO2 0.06 0.12 0.6 0.29 bdl 0.33 Al2O3 0.84 3.15 9.8 9.43 0.70 9.8 Cr2O3 bdl bdl bdl bdl bdl bdl FeO 0.27 0.29 0.8 0.7 0.46 0.6 MnO bdl bdl bdl bdl bdl bdl MgO 39.0 37.6 17.2 34.8 38.6 34.3 CaO 0.44 1.3 22.6 1.5 0.35 1.9 Na2O bdl bdl bdl bdl bdl bdl K2O bdl bdl bdl bdl bdl bdl Total 99.9 100.0 100.3 100.2 99.3 99.7 Note: Profile 1 (white arrow in Fig. 4d); Profile 2 (white arrow in Fig. 4d); Profile 3 (black arrow in Fig 4b); bdl = below detection limit; Px2-B8 = 0.84: low-Ca pyroxene (0.84 wt% Al2O3); (6) = mean of six analyses; detection limits (in ppm): TiO2 (320); Cr2O3 (440); MnO (300); Na2O (280); K2O (280). *Phases with secondary ion mass spectrometry analysis. Table 2. Major element composition of glasses (glass inclusions and mesostasis) and olivine (in wt%). Mesostasis and coexisting olivines S. I. T3 S. I. T4 S. I. B16 S. I. B17 S. I. B1 CMG-T3 (5)* Ol 2-T3 Ol 1-T3* CMG-T4 (2)* Ol22-T4 Ol23-T4 CMG-B16 (4) Ol47-B16 Ol49-B16 CMG B17 (2) OlB-17 RMG-B1 (33)* OlB1-6 OlB1-7 SiO2 49.2 42.0 42.1 48.9 42.2 42.2 49.7 42.6 42.2 48.4 42.6 49.2 41.1 42.2 TiO2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0.05 bdl bdl Al2O3 28.1 bdl bdl 28.3 bdl bdl 27.7 0.08 0.06 29.8 bdl 25.9 0.06 0.11 Cr2O3 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0.09 bdl 0.05 FeO 0.44 0.23 0.42 0.8 0.7 0.8 0.9 0.49 0.48 0.34 0.41 0.7 0.31 0.45 MnO bdl bdl bdl bdl bdl bdl 0.01 bdl bdl bdl bdl bdl bdl bdl MgO 2.7 56.7 56.9 3.6 56.9 56.8 2.6 56.7 56.8 3.95 56.7 6.6 57.6 56.2 CaO 20.1 0.11 0.12 19.8 0.08 0.08 18.5 0.12 0.13 17.5 0.11 17.4 0.12 0.10 Na2O bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl K2O 0.03 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl Total 100.5 99.0 99.5 101.3 99.9 99.9 99.4 100.0 99.7 100.0 99.8 100.0 99.2 99.1 Glass inclusions and host olivines S. I. T1 S. I. T6 S. I. B#5 S. I. B5 S. I. B16 G.I.1* Ol Host* G.I.T6 Host Ol (15) G.I.B#5* Ol Host* G.I.B5 (3) Host Ol G.I. B16 Host Ol SiO2 57.0 42.8 56.6 42.3 56.8 42.4 56.6 42.5 53.9 42.6 TiO2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl Al2O3 21.4 bdl 21.1 bdl 21.3 bdl 22.0 0.09 24.9 bdl Cr2O3 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl FeO 0.19 0.19 0.35 0.49 0.27 0.3 1.3 1.4 0.6 0.49 MnO bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl MgO 1.6 57.2 3.3 57.4 2.5 56.4 2.1 56.5 1.7 56.7 CaO 19.6 0.16 18.9 0.10 19.2 0.12 18.3 0.19 17.6 0.10 Na2O bdl bdl bdl bdl bdl bdl 0.06 bdl 0.03 bdl K2O bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl Total 99.8 100.4 100.3 100.3 100.1 99.2 100.4 100.7 98.7 99.9 Note: S.I. = silicate inclusion; CMG = clear mesostasis glass; MRG = recrystallized mesostasis glass; (33) = mean of 33 analyses; G.I. = glass inclusion; bdl = below detection limit; detection limits (in ppm): TiO2 (320); Al2O3 (150); Cr2O3 (440); MnO (300); Na2O (280); K2O (280). *Phase with secondary ion mass spectrometry analysis. All silicate phases are poor in Fe, Mn, Cr, and alkali elements. Olivine typically has FeO contents between 0.19 and 1.38 wt% with most of the analyses clustering near the lower end of the range. The Al2O3 content is slightly variable (<0.03–0.11 wt%) with CaO contents varying from 0.08 to 0.19 wt%. The contents of MnO and TiO2 are below the detection limit of the EMP (330 and 320 ppm, respectively). Pyroxenes have highly varying chemical compositions. The cracked, polysynthetically twinned clinoenstatite, which is commonly associated with olivine in large multiphase aggregates, has Al2O3 and CaO contents of 0.66–1.83 and 0.35–0.51 wt%, respectively. The FeO content varies from 0.25 to 0.46 wt% and the TiO2 and Cr2O3 contents from 0.04 to 0.08 wt% and <0.04 to 0.07 wt%, respectively. The contents of Mn, Na, and K are mostly below the detection limit of the EMP. Aluminum-rich, Ca-poor orthopyroxene, which poikilitically encloses olivine and Al-poor clinoenstatite, has Al2O3 contents between approximately 2 and 18 wt%. It is poor in FeO (0.5–0.8 wt%) and Cr2O3 (0.04–0.08 wt%), contains some TiO2 (up to 0.4 wt%) but is free of Mn and alkali elements. Calcium-rich clinopyroxenes are present as small grains in contact with anorthite and Al-rich orthopyroxene that form serrated surfaces and symplectitic intergrowths with brezinaite. Clinopyroxene also has highly variable Al2O3 contents, which vary from about 7 to 17.7 wt%. It is also poor in FeO (∼0.4–0.7 wt%), contains some TiO2 (0.1–0.2 wt%) and Cr2O3 (up to 0.06 wt%), but no significant amounts of Mn and alkali elements. Glasses (e.g., primary glass inclusions in olivine and mesostasis glass) have a Ca-Al-Si-rich composition (Table 2). Inclusion glass (GI) and CMG have similar CaO contents (∼20 wt%; Figs. 5a and 5b) but differ in their Al2O3 and SiO2 contents. GIs have Al2O3 and SiO2 contents varying from 21 to 24.9 wt% and from 53.9 to 57 wt%, respectively. Concentrations in the mesostasis glass vary from 25.9 to 28.3 wt% Al2O3 and 48.1–49.2 wt% SiO2. This results in a superchondritic CaO/Al2O3 ratio for GI and a subchondritic one for the CMG (Figs. 5a and 5b). GIs as well as mesostasis glasses are very poor in TiO2 and FeO, which vary from <0.03 to 0.6 wt% and 0.5–1.18 wt%, respectively. Both types of clear glasses are also very poor in Cr2O3, MnO, and alkali elements (all LuN) patterns with abundances varying around 5–10 × CI. Moderately, volatile element Li is depleted in G.I.B.#5 (∼3 × CI) but not in G.I.1 and Cr and Mn are strongly depleted with respect to the refractory elements. Table 3. Trace element contents of glass inclusion and mesostasis glasses and host olivine of the Tucson iron meteorite. Secondary ion mass spectrometry data in ppm (wt). Typical errors are approximately 10%, when larger they are given in parentheses in units of the last digit. G.I.1 G.I.1Ol host G.I.B#5 G.I.B#5Ol host CMG-T3 Ol 1-T3 CMG-T4 CMG-B17 Ol- B17 RMG-B1 Li 24.4 0.69 5.09 0.36 35 1.07 20.4 13.6 0.8 14.8 Na 798 135 0.56 941 K 219 5 2.27 28.4 0.19 502 11.4 0.55 12.8 Ca 904 863 82,105 734 76,456 Sc 4.9 3.53 10 6.51 2.3 (3) 1.08 8 8.3 2.78 9.2 Ti 37 81.3 18.8 18 34 71.9 37 28 66.5 87 V 29.4 14.1 8.3 11.1 7.2 14.7 67 9 12.3 4.1 Cr 503 336.7 140 167 111 360 1780 92.1 226 440 Mn 129 89 35.8 106 72.5 30.9 87.3 Fe 3067 3440 1825 3938 944 6110 Co 9.5 19.5 14.9 785 20 1.84 Sr 77 50 0.01 (2) 318 0.03 169 91.7 0.05 98.5 Y 13 7.8 0.075 14.3 0.03 8.7 8 0.022 6.7 Zr 34 17.1 0.02 (4) 77 0.02 27 25.5 0.017 (2) 24.6 Nb 0.03 (1) 0.6 (7) 0.007 (2) 0.04 (5) Ba 32 31.6 0.02 (6) 175 0.007 (2) 58 49 0.03 (4) 58.1 La 1.4 0.95 5.6 1.5 (2) 1.57 0.001 (5) 1.57 Ce 6.2 5.1 18.2 5.7 5.1 0.003 (8) 5.8 Pr 0.81 0.81 (9) 2.3 0.8 (1) 0.63 0.0006 (3) 0.64 Nd 3.7 3.2 9.7 2.9 2.8 2.92 Sm 1.4 (2) 1.0 (2) 3 1 1.01 0.98 Eu 0.40 (5) 0.56 (8) 1.3 0.3 (6) 0.45 0.45 Gd 1.9 1.8 (3) 3.2 1.1 (2) 0.9 (1) 1.04 Tb 0.36 0.32 (6) 0.37 (5) 0.2 (3) 0.15 (2) 0.15 (2) Dy 2.2 2.2 2.6 1.3 1.39 1.29 Ho 0.41 0.38 (6) 0.54 (6) 0.3 (4) 0.28 0.25 Er 1.12 0.004 1.1 1.56 0.006 (1) 0.67 0.85 0.74 Tm 0.15 (2) 0.001 0.14 (4) 0.16 (3) 0.12 (2) 0.11 0.09 (1) Yb 0.91 0.019 0.9 (1) 1.2 0.016 (2) 0.9 (1) 0.87 0.008 (2) 0.78 Lu 0.1 (2) 0.005 0.19 (3) 0.12 (3) 0.1 0.003 (1) 0.1 Clear mesostasis glasses CMG-T3 and CMG-B17 as well as recrystallized matrix glass RMG-B1 have trace element abundances very similar to those of GIs (Fig. 6b). The refractory elements have abundances between about 5 × CI and 20 × CI. Exceptions are again Nb (∼0.1 × CI), Ti (∼0.1 × CI), Sc (∼1 × CI), and V (∼0.1 × CI), which are depleted with respect to the other refractory elements. The moderately volatile element Li has in all samples a higher normalized abundance than the refractory elements (∼10 × CI) and Cr and Mn are strongly depleted (∼0.04 × CI). The CMG-T3 is richer in most refractory trace elements than all other glasses (up to ∼75 × CI for Ba; Fig. 6b) and it has a fractionated REE pattern with LaN > LuN and abundances between 7 and 30 × CI. It also has high contents of Zr (∼20 × CI), Y (∼10 × CI), Sr (∼30 × CI), Li (∼25 × CI), and Ba (∼75 × CI). The moderately volatile elements Cr and Mn are depleted similar to the refractory elements Ti and Nb with respect to all other refractory lithophile elements (∼0.05 × CI; Figs. 6a and 6b). Volatile alkali elements such as Na and K have v
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