| | Journal (article/letter/editorial) | Wl6-7037/87/%3.00 + .oO The Semarkona meteorite: First recorded occurrence of smectite in an ordinary...hydrothermally altered. Analyses of Abstract-Semarkona altered materials and opaque matrix are presented...calcite and Na, Fe smectite, respectively. In Semarkona the process possibly requires open system behavior...The low petrologic type previously assigned to Semarkona is the result of retrograde metamorphism, under... of a higher temperature mineral assemblage. Semarkona, and possibly Bishunpur, should be assigned to | | | Journal (article/letter/editorial) | Fractionated sulfur isotopes in sulfides of the Kaidun meteorite HARRYY. MCSWEEN, JR.'*, LEER. RICIPUT12 AND BRUCEA...37996, USA 2Chemistry and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee...form 1996 September 12) Abstract-The Kaidun meteorite contains carbonaceous chondrite (CM 1) clasts...needles wrapped by sheaths of phyllosilicate, and pentlandite forms veins that crosscut aggregates of phyllosilicate...much as 4 . 2 % 0 for pyrrhotite and -5.7%0 for pentlandite), unlike sulfides in other carbonaceous chondrites | | | Journal (article/letter/editorial) | Widespread evidence for high-temperature formation of pentlandite in chondrites Devin L. Schrader a,⇑, Jemma Davidson...them to the metamorphic history of their host meteorite. Sulfides in Mighei-like carbonaceous chondrites...consistent with formation during chondrule cooling for Semarkona (LL3.00) and during cooling after thermal metamorphism...metamorphism. Contrary to the assertion that pentlandite is solely the product of low-temperature aqueous...Elsevier Ltd. All rights reserved. Keywords: Pentlandite; Pyrrhotite; Exsolution; High-temperature; Annealing; | | | Journal (article/letter/editorial) | ZOLENSKY Earth Science and Solar System Exploration Division, NASA, Johnson Space Center, Houston, Texas 77058...minerals into the lunar regolith. The Bench Crater meteorite also provides a glimpse of the petrography of...this time we had assumed that the Bench Crater meteorite is anhydrous, with only dehydrated phyllosilicates...al., 1974). I have examined the Bench Crater meteorite, a chondrite recovered from the lunar regolith...reported recently by Zolensky et al. (1 996a). This meteorite measures only 3 mm in greatest dimension and exists | | | Journal (article/letter/editorial) | major phases and serpentine, magnetite, and pentlandite are minor phases. Anhydrous silicates are entirely...determined by EPMA analysis. Compositional fields of Semarkona, Tagish Lake carbonate-poor, and Bells are also...versus c) SiO2 versus Na2O. diagrams of SK series Semarkona LL3 chondrite, lithology, and Bells CM obtained...decomposition (Fig. 8e). Pentlandite is much less abundant than pyrrhotite and only one pentlandite grain was identified...micrometeorites do not show K-enrichment. In addition, the Semarkona LL3 chondrite, which consists largely of hydrous | | | Journal (article/letter/editorial) | Printedin U.S.A. + .oO The microstructure of Semarkona and Bishunpur C. M. O’D. ALEXANDER,“* D. J. BARBER...24, 1989) Abstract-The ordinary chondrites, Semarkona and Bishunpur, appear to have experienced in situ...examination of them, which supports this conclusion. In Semarkona, all but the most magnesian mafic minerals have...composition of the gas present during the alteration of Semarkona was not solar but was dominated by H20. The formation...grain-boundary fluid present. The alteration in Semarkona and Bishunpur is far from complete. Thermodynamic | | | Journal (article/letter/editorial) | Fe-Ni and troilite; in some cases, magnetite and pentlandite occur along with or instead of troilite and metallic...haxonite - (Fe,Ni)23C6), kamacite, troilite, re pentlandite and Ni-rich metal (e.g., Taylor et al., 1981;...carbides (Krot et al., 1997). Evidence from LL3.0 Semarkona that water moved through the matrix into chondrules...high-17O composition of magnetite grains in LL3.00 Semarkona, L3.05 EET 90161, LL3.6 Ngawi and other type-3...temperatures ranging from 200 - 260ºC for type-3.00 Semarkona (Alexander et al., 1989; Huss and Lewis, 1994) | | | Journal (article/letter/editorial) | porphyritic olivine compound chondrule from LL3.0 Semarkona that experienced limited remelting Alan E. RUBIN...April 2006) Abstract–Chondrule D8n in LL3.0 Semarkona is a porphyritic olivine (PO) chondrule, 1300...the exterior region of the chondrule formed pentlandite and abundant magnetite. INTRODUCTION Some researchers...with low-FeO overgrowths in the LL3.0 chondrite Semarkona. The chondrule contains metal blebs (formed by...I examined thin section AMNH 4128-2 of LL3.0 Semarkona in transmitted light and in backscattered electron | | Prasad, M. Shyam, Rudraswami, N. G., De Araujo, Agnelo, Babu, E. V. S. S. K., Vijaya Kumar, T. (2015) Ordinary chondritic micrometeorites from the Indian Ocean. Meteoritics & Planetary Science, 50 (6) 1013-1031 doi:10.1111/maps.12451 | Journal (article/letter/editorial) | Institute of Oceanography, Dona Paula, Goa 403004, India LAM-ICP-MS National Facility, CSIR-National Geophysical...Research Institute, Uppal Road, Hyderabad 500007, India * Corresponding author. E-mail: shyam@nio.org ...micrometeorites overlap and extend the range of the known meteorite types, therefore constitute an extremely valuable...et al. 1997) with smaller percentages of other meteorite types in the total flux (Taylor et al. 2007)....carbonaceous chondrites comprise a miniscule ~3% of the meteorite flux (Krot et al. 2003). More recently, micrometeorites | | | Journal (article/letter/editorial) | EET 92011 contains assemblages composed of pentlandite, troilite, and Ni-rich metal. The assemblages...Renazzo contain tochilinite, magnetite, troilite, pentlandite, and phosphate. In all of the assemblages in...grained and intimately mixed with troilite, pentlandite, or magnetite. Opaque assemblages in CR chondrites...rights reserved. 1. INTRODUCTION The Renazzo meteorite was first identified as distinct from other carbonaceous...87320,10 and EET 92011,5, both from the Antarctic Meteorite Collection at Johnson Space Center, as well as | | | Journal (article/letter/editorial) | 6 unequilibrated ordinary chondrites (UOCs) (Semarkona [LL 3.0], Bishunpur [L/LL 3.1], Krymka [LL 3.1]...that previous studies pointed to the OM in this meteorite as being the most pristine among all chondrites...metamorphic grade: 1) follows the hierarchy Renazzo << Semarkona << other UOCs; 2) is well correlated to the petrographic...discrimination between Renazzo, Semarkona, and other UOCs shows: 1) Semarkona is a very peculiar UOC—by far...that fine-grained chondrule rims and matrix in Semarkona could be the source of smectite-rich IDPs is not | | | Journal (article/letter/editorial) | light isotope enrichment for the LL3 chondrite Semarkona, to +2.7%0 per mass unit for the LL3 chondrite...was prevalent in CAI inclusions in the Allende meteorite. The oxygen anomaly led to the revision of theories...is evidence from these data that Bishunpur and Semarkona contain isotopically fractionated Cd. This is...to be enhanced in the heavier isotopes while Semarkona is depleted in these isotopes. Because the measurement...Isotopic ratios a of cadmium in whole rock meteorite samples Meteorite Type ALHA-77299,30 c,d H3 measured | | Krot, Alexander N., Zolensky, Michael E., Wasson, John T., Scott, Edward R.D., Keil, Klaus, Ohsumi, Kazumasa (1997) Carbide-magnetite assemblages in type-3 ordinary chondrites. Geochimica et Cosmochimica Acta, 61 (1) 219-237 doi:10.1016/s0016-7037(96)00336-5 | Journal (article/letter/editorial) | USA 3Earth Science and Solar System Exploration Division, NASA, Johnson Space Center, Houston, Texas 77058...accessory taenite and pentlandite was originally described in LL3.0 Semarkona, LL3.7 ALHA77278, and LL3...Hutchison et al. (1987) described carbide veins in Semarkona matrix and a carbide that might be intermediate...cohenite and e-carbide (Fe2C). They concluded that Semarkona experienced multistage nebular and parent body...Cr, and troilite from the Canyon Diablo iron meteorite for S; C was not analyzed. For silicates and magnetite | | | Journal (article/letter/editorial) | chondrites, formed prior to final lithification of the meteorite and probably prior to parent body accretion. We...possible that matrix may differ in origin from meteorite to meteorite, thus reflecting the diversity of environments...the American Museum of Natural History (AMNH) meteorite collection were studied using a petrographic microscope...described in some ordinary chondrite matrices (e.g., Semarkona), with the latter predominating (Hutchison e f...areas consist of submicrometer chromite and pentlandite. The overgrowth does not occur on broken surfaces | | McCanta, M.C., Treiman, A.H., Dyar, M.D., Alexander, C.M.O’D., Rumble, D., Essene, E.J. (2008) The LaPaz Icefield 04840 meteorite: Mineralogy, metamorphism, and origin of an amphibole- and biotite-bearing R chondrite. Geochimica et Cosmochimica Acta, 72 (23) 5757-5780 doi:10.1016/j.gca.2008.07.034 | Journal (article/letter/editorial) | elsevier.com/locate/gca The LaPaz Icefield 04840 meteorite: Mineralogy, metamorphism, and origin of an amphibole-...online 11 September 2008 Abstract The R chondrite meteorite LaPaz Icefield (LAP) 04840 is unique among metamorphosed...albite (An8Ab90Or2), magnetite, pyrrhotite, pentlandite, and apatite. Ferromagnesian minerals are rich...ordinary chondrite phyllosilicates (as in the Semarkona chondrite), and insoluble organic matter (IOM)...mccanta@ gmail.com (M.C. McCanta). 1 Present address: Division of Geological and Planetary Sciences, California | | | Journal (article/letter/editorial) | chondrites. We studied bleached chondrules from Semarkona by ion microprobe for trace elements and H isotopes...by phyllosilicates, troilite was altered to pentlandite, but pyroxene was completely unaffected. Calcium-rich...chondrites, especially in the wellstudied falls Semarkona, Bishunpur, Chainpur, and Tieschitz, most of the...the highly unequilibrated ordinary chondrites, Semarkona (LL3.0) and Bishunpur (L3. I), led to our "rediscovery"..."rediscovery" of bleached chondrules. For Semarkona section USNM 1805-7, a 4 x 5 grid of 20 maps, each containing | | | Journal (article/letter/editorial) | called ‘‘poorly characterized phases’’ or PCP), pentlandite and Ni-bearing pyrrhotite. We studied 11 CM chondrites...alteration. The extent of alteration varies from meteorite to meteorite. Some rocks (e.g., Murchison; QUE 97990;...Samples, petrographic types, and weathering grades Meteorite Section number Fall or find Petrographic type... Alteration of CM chondrites 91600, a CM-related meteorite that previous studies had suggested had been metamorphosed...rectangular blocks. Standards included the Allende meteorite, the USGS standards granite G-2 and basalt BHVO-1 | | Sutton, S., Alexander, C.M.O'D., Bryant, A., Lanzirotti, A., Newville, M., Cloutis, E.A. (2017) The bulk valence state of Fe and the origin of water in chondrites. Geochimica et Cosmochimica Acta, 211. 115-132 doi:10.1016/j.gca.2017.05.021 | Journal (article/letter/editorial) | Fe XANES to determine the Fe valences of bulk meteorite powders in Orgueil (CI1), a number of CMs and...experienced varying degrees of alteration, and Semarkona (LL3.00). The total ranges of bulk Fe valences...Orgueil 2.77, CMs 2.40-2.63, CRs 1.46-2.54, and Semarkona 2.10. Combining previous estimates of the present...fractional water losses to have been: Orgueil 15-26 %, Semarkona 73-83 %, CMs 23-48 %, and CRs 39-62 %. The associated...CMs -676 ‰ to -493 ‰, CRs -527 ‰ to -56 ‰, and Semarkona -527 ‰ to 154 ‰. The CI, CM, CR and ordinary chondrites | | | Journal (article/letter/editorial) | near the surface of some chondrules in LL3.0 Semarkona, and silica-rich igneous rims around many type-I...grains derived from disrupted type-IA chondrules. Semarkona chondrule mesostases that show increased concentrations...(FeO-rich porphyritic olivine—PO) chondrules in Semarkona LL3.0 and found that most phenocrysts exhibit...Meteoritical Society, 2018. 2 A. E. Rubin Semarkona, and silica-rich igneous rims around many type-I...ANALYTICAL PROCEDURES Two thin sections of LL3.0 Semarkona (USNM 1805-3 and AMNH 4128-2) were examined microscopically | | JOSWIAK, David J., BROWNLEE, Donald E., MATRAJT, Graciela, WESTPHAL, Andrew J., SNEAD, Christopher J., GAINSFORTH, Zack (2012) Comprehensive examination of large mineral and rock fragments in Stardust tracks: Mineralogy, analogous extraterrestrial materials, and source regions. Meteoritics & Planetary Science, 47 (4) 471-524 doi:10.1111/j.1945-5100.2012.01337.x | Journal (article/letter/editorial) | Hzlwd = heazlewoodite, Ko = kosmochloric, Pent = pentlandite, Pyrr = pyrrhotite, Sph = sphalerite, Roed =...Pyrr = pyrrhotite, Sph = sphalerite, Pent = pentlandite, Fo = forsterite, Plag = plagioclase, An = anorthite...free or nearly free of aerogel melt and MSG. Pentlandite was observed in fragments 2, 9, and 13 (Table...that was composed of pyrrhotite+ sphalerite+pentlandite, which disaggregated into smaller pieces during...Pyrrhotite Frag 13 Frag 9 d e Ni Ni Fe S h c pentlandite Cu Fe-Zn sulfide Zn Frag 7 Fe Fe Mn Pyrr | | | Journal (article/letter/editorial) | Are phyllosilicates the same throughout the meteorite? How does the alteration assemblage in Kaba compare...near Kaba, Hungary, in 1857, and the bulk of the meteorite is kept in the museum at the College of the Reformed...presence of a minor sulfide phase, possibly pentlandite, mixed with the saponite. Matrix FIG. 4. Hip-~iution...larger role in the alteration of the Lance CO3 meteorite than in Kaba (KELLERand BUSECK, 1990). The combination...mineralogy could form. From a study of the Orgueil meteorite, TOMEOKAand BUSECK(1988) also suggested that CI | | | Journal (article/letter/editorial) | FeO-rich olivine, low-Ca pyroxene, and sulfides (pentlandite and troilite). The clast’s matrix contains coarse...which could have only been preserved if this meteorite was not subjected to any significant thermal metamorphism...have only been identified in clasts in one other meteorite, the LL3.1 ordinary chondrite Krymka (e.g., Semenenko...analysis by the Johnson Space Center Antarctic Meteorite Collection. QUE 99177 was classified as Antarctic...clast is coarser-grained than matrix in the host meteorite. It contains olivine, amphiboles, sulfides, and | | Joswiak, D. J., Brownlee, D. E., Matrajt, G., Westphal, A. J., Snead, C. J. (2010) Kosmochloric Ca-rich pyroxenes and FeO-rich olivines (Kool grains) and associated phases in Stardust tracks and chondritic porous interplanetary dust particles: Possible precursors to FeO-rich type II chondrules in ordinary chondrites. Meteoritics & Planetary Science, 44 (10) 1561-1588 doi:10.1111/j.1945-5100.2009.tb01192.x | Journal (article/letter/editorial) | = silicate glass, pyrr = pyrrhotite, pent = pentlandite, En = enstatite trid = tridymite, roed = roedderite...particle from track 141 (Coki) showing large pentlandite grain with attached Kool grain. b) Dark-field...Heavy dashed white line shows edge of attached pentlandite. Lighter dashed white line near the top of the...Ko-aug = kosmochloric augite, G = glass, P = pentlandite. pyroxenes occur in fine-grained assemblages...observed this assemblage attached to a large pentlandite TP (Fig. 2a) along a sharp contact. The original | | | Journal (article/letter/editorial) | Society, 1997. Printed in USA. Mineralogy of meteorite groups ALANE. RUBIN Institute of Geophysics and...shocked ordinary chondrites. Secondary minerals in meteorite finds that formed during terrestrial weathering...numbers of meteorites (including members of new meteorite groups; Table 1) from hot and cold deserts, the...variations 23 1 A. E. Rubin 232 TABLEI . Meteorite classification. Chondrites Carbonaceous chondrites...Wasson and Kallemeyn, 1990). 233 Mineralogy of meteorite groups TABLE 2. Minerals in meteorites. ~~ ~ | | | Journal (article/letter/editorial) | kamacite. Fe-Ni metal grains in chondrules in Semarkona typically show plessitic intergrowths consisting... Among the known ordinary and CO chondrites, Semarkona is the most primitive. The range of metamorphic...Acfer 094, a true type 3.00 chondrite, than in Semarkona, which should be reclassified as type 3.01. INTRODUCTION...chondrites, except for bulk metal compositions in Semarkona chondrules (Kimura and Weisberg 2004), and the...the bulk chemical composition of Semarkona chondrules (Grossman and Wasson, 1985). Because CH and CR chondrites |
|