Temat: ordinary chondrites - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Two spinel-bearing compound chondrules from the Baszkówka meteorite
Autorzy:: Borucki, J.
Stępniewski, M.
Powiązania:: https://bibliotekanauki.pl/articles/2059304.pdf
Data publikacji:: 2001
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: Baszkówka
meteorites
ordinary chondrites
spinel
Opis:: The present paper describes two compound chondrules labelled panda and chevron, discovered in the Baszkówka meteorite. Optical microscope, electron microscope and electron microprobe studies revealed an unusual mineral composition and fabric. Both chondrules include "primary" and "secondary" components. The panda and chevron chondrules have apparent diameters of ~0.86 and ~0.54 mm respectively with spinel dominant in primary components and olivine-plagioclase in secondary components overlain by thin microcrystalline rims. Euhedral or subhedral Mg, Fe2+/Al, Cr-spinel crystals from the panda's primary component (zoned, cavernous or homogeneous) were not found in Mg-Fe chondrules in Baszkówka, where Cr occurs exclusively as chromite. Olivine crystals from panda's primary (Fa27.1) and secondary (Fa26.5) component have similar compositions to those from panda's rim (Fa26.4) and comparable to olivine from other Baszkówka Mg-Fe chondrules (average ~Fa25.7). The Ca-plagioclase laths from the groundmass of panda's primary component has an extremely variable composition (~An49 to ~An60), evidently more calcic than those in other chondrules of the meteorite (mean ~An13). The primary components of the two spinel-bearing chondrules may have been formed in a fireball generated by powerful impact during early accretion of a protoplanet. After crystallisation the spinel crystals were abraded and polished, probably during rapid flight through a dense cloud of interplanetary dust. The moderately reducing conditions of the hypothetical fire ball were replaced by a more reducing environment during the condensation of the rims of both chondrules.
Źródło:: Geological Quarterly; 2001, 45, 3; 281-288
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The Songyuan ordinary chondrite (China) - rich in alien rock fragments and its reclassification
Autorzy:: Borucki, J.
Giro, L.
Orłowski, R.
Stępniewski, M.
Powiązania:: https://bibliotekanauki.pl/articles/2059203.pdf
Data publikacji:: 2009
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: Songyuan
meteorites
ordinary chondrites
classification
rock fragments
Opis:: The Songyuan chondrite is composed mostly of minerals and chondrule types common in equilibrated ordinary chondrites. More distinctively, the Songyuan material includes numerous sintered cryptocrystalline rock lumps, possible chondrule precursors, and less frequent fragments of olivine-pyroxene basalt. The moderate porosity (estimated under the polarizing microscope at a few percent by volume) and un compacted metal grains, suggest that the meteorite came from very shallow horizons of the regolith. The shallow original position of the Songyuan fragment on its parent body is consistent also with the abundance of numerous euhedral crystals of the main meteoritic components present in the interstitial pores. They crystallized most probably from fluids migrating through the superficial horizons from the in ner parts of the Songyuan parent body. The structural characteristics and slight differentiation in olivine composition suggests a high degree of homogenization and, together with the median value of the fayalite content (26.2 š0.24 wt.%), corre sponds to the L5 chemical-petrologic group of equilibrated ordinary chondrites. More over, the homogenous extinction in the olivine crystals and the absence of multiple planar fractures indicate the lowest level of the shock metamorphism (S1), whereas the lack of any oxide rims around kamacite and troilite grains points to the lowest level of weathering (W0).
Źródło:: Geological Quarterly; 2009, 53, 2; 187-198
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Petrography of the Baszkówka chondrite
Autorzy:: Siemiątkowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/2059299.pdf
Data publikacji:: 2001
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: Baszkówka
ordinary chondrites
chondrules
structure
petrography
classification
origin
Opis:: The Baszkówka chondrite comprises chondrules, individual crystals of olivine, xenomorphic concentrations of kamacite and troilite, matrix and pores up to 3.0 mm in diameter; porosity reaches 20% by volume. Measurements of 697 chondrules in an area of 250 m2 enabled distinction of three populations. The chondrules and olivine crystals have been sintered at high temperatures. Six structural types showing transitions between porphyritic and granular structures have been discriminated. Rims showing a similar diversity surround about 10% of chondrules. The composition and structure of the chondrules suggest a source from the nebular dust disk around the Sun. The abudance of voids and their relatively large size and a lack of fissures, indicate a small size of the host body, which must have been derived from an early phase of protoplanet formation.
Źródło:: Geological Quarterly; 2001, 45, 3; 263-280
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Oxygen-isotopic compositions of minerals from the Baszkówka chondrite
Autorzy:: Maruyama, S.
Powiązania:: https://bibliotekanauki.pl/articles/2059312.pdf
Data publikacji:: 2001
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: Baszkówka
meteorites
ordinary chondrites
chondrules
spinel
oxygen isotopes
Opis:: Oxygen isotopic compositions of two picotite-bearing chondrules from Baszkówka L5(S1) equilibrated ordinary chondrite have been determined by secondary ion mass spectrometry. The O-isotopic compositions of the minerals in the picotite-bearing chondrules are slightly more 16O-rich than the bulk O-isotopic composition of Baszkówka. The petrological properties and the O-isotopic compositions of these chondrules suggest that they have closer relationship to ferromagnesian chondrules than CAIs. The 16O-enrichment of the picotite-bearing chondrules may result from incomplete O exchange reaction between 16O-rich chondrule precursors and the 16O-poor solar nebular gas. This implies that the picotite-bearing chondrules are more primitive than ordinary ferromagnesian chondrules in Baszkówka. The O-isotopic compositions of the minerals in one of these chondrules relate to the crystallization sequence. These O-isotopic variations of minerals within the chondrule may result from incomplete O exchange between the chondrule melt droplet and the nebular gas. The heterogeneity of the O-isotopic composition in Baszkówka indicates that Baszkówka has not been homogenized completely during thermal metamorphism and/or secondary alteration.
Źródło:: Geological Quarterly; 2001, 45, 3; 303-312
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Próby klasyfikowania chondrytów zwyczajnych przez zastosowanie spektroskopii mössbauerowskiej
Attempts of classification of ordinary chondrites by application of Mössbauer spectroscopy
Autorzy:: Gałązka-Friedman, Jolanta
Woźniak, Marek
Duda, Przemysław
Jakubowska, Martyna
Bogusz, Patrycja
Karwowski, Łukasz
Powiązania:: https://bibliotekanauki.pl/articles/1032381.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Meteorytowe
Tematy:: Mössbauer spectroscopy
classification of meteorites
ordinary chondrites
Opis:: Mössbauer spectra of equilibrated ordinary chondrites consist of two sextets due to magnetically ordered iron present in metallic phases and troilite and two doublets due to paramagnetic iron present in olivines and pyroxenes. The Mössbauer spectral areas of the different mineralogical phases in meteorites are proportional to the number of iron ions present in olivines, pyroxenes, metallic phase and troilite. This property of Mössbauer spectra was the basis for constructing various methods for the classification of ordinary chondrites. Review of these methods will be presented.
Źródło:: Acta Societatis Metheoriticae Polonorum; 2019, 10; 23-28
2080-5497
Pojawia się w:: Acta Societatis Metheoriticae Polonorum
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: NWA 14360 – Nowy meteoryt z Nigru
A new meteorite from Niger: NWA 14360
Autorzy:: Karwowski, Łukasz
Szopa, Krzysztof
Powiązania:: https://bibliotekanauki.pl/articles/2034032.pdf
Data publikacji:: 2022-03
Wydawca:: Polskie Towarzystwo Meteorytowe
Tematy:: ordinary chondrites
NWA 14360
meteorite
meteorites classification
Opis:: The new meteorite was bought as one single stone in 2019 from a dealer in Niger by Tomasz Jakubowski. The meteorite has fusion crust. It contains chondrules of different types with dominance of barred olivine chondrules, with diameter to 1.5 mm. Px and Ol are 78.1 vol%. of the meteorite mass. Pl is up 11.8 vol%. Average fayalite content is 24.93. Metallic phases are 3.0 vol%. Troilite is up to 5.9 vol%. Spinel (Cr-spinel) is up to 0.9 vol%. Average content of the secondary Fe-rich minerals (e.g. hydroxides) is 0.4 vol%. Feldspar composition is: Ab80.2Or5.0An14.8. Mean content of Al2O3, MgO and TiO2 in chromium spinel is 6.70 wt%, 2.05 wt% and 2.02 wt%, respectively. Metal phases are kamacite and tetrataenite. The kamacite has a Ni content in the range 5.83–6.81 wt%, while the Co content is in the range 0.39 to 0.56 wt%. Tetrataenite is has Ni content from 49.68 to 50.46 wt%, and Co up to 0.05 wt%. High-Ca monoclinic pyroxene, similar to diopside, is very rare. Accessory minerals are: chlorapatite and merrylite. Base on chemistry and petrography, the meteorite is classified as ordinary chondrite (L5). The main mass, a 9190 g specimen, is in Krzysztof Socha private collection. Small fragments with the total mass 71 g are stored in Museum of Earth Sciences (catalogue no: WNoZ/Mt/110) at University of Silesia in Katowice, Poland. 39 g was used for thin-section preparation and spectroscopic investigation (Mössbauer spectroscopy).
Źródło:: Acta Societatis Metheoriticae Polonorum; 2022, 13; 47-59
2080-5497
Pojawia się w:: Acta Societatis Metheoriticae Polonorum
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Mineralogy of the Baszkówka chondrite (L5 S1): new data on silicates, opaques and minor minerals
Autorzy:: Borucki, J.
Stępniewski, M.
Powiązania:: https://bibliotekanauki.pl/articles/2059302.pdf
Data publikacji:: 2001
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: Baszkówka
meteorites
ordinary chondrites
minerals
spinel
picotite
Opis:: The mineral composition of the Baszkówka meteorite comprises: olivine, pyroxenes, plagioclase, Fe,Ni metal, troilite and chromite with minor chlorapatite, whitlockite, magnetite, haematite, spinel, idaite, calcite and native Cu. A rare variety of spinel (picotite), probably the oldest among the minerals of Baszkówka, was identified in the only two chondrules named: panda and chevron. The composition of the olivine (Fa 26.2š1.8 wt.%) and the high degree of chondrite homogenisation, a result of thermal metamorphism, are consistent with earlier results and indicate the L5 group. No distinct shock effects were observed in Baszkówka, classified as S1. Troilite-Fe,Ni and Fe,Ni metal lumps are defined and interpreted as molten planetesimals impact splashes.
Źródło:: Geological Quarterly; 2001, 45, 3; 229-256
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Osłabianie promieniowania gamma w chondrytach zwyczajnych
Gamma rays attenuation in ordinary chondrites
Autorzy:: Kaczmarzyk, Marcin
Powiązania:: https://bibliotekanauki.pl/articles/1032387.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Meteorytowe
Tematy:: ISRU
asteroids
astronautics
cosmic rays
gamma rays attenuation
ordinary chondrites
Opis:: This paper elaborates on gamma rays attenuation in ordinary chondrites. Highly penetrating gamma radiation is emitted as a result of inelastic collisions of ultra-high energy cosmic particles with bulk matter, such as spacecraft hulls. Resources mined from Solar System small bodies may present an alternative construction material for spacecraft cosmic rays shields, which explains research on ionizing radiation attenuation in meteorites. A custom-made, shielded research workstation was constructed to analyse ionizing radiation absorption in pulverized materials. Using the workstation, gamma rays attenuation experiment was performed on pulverized ordinary chondrite – a meteorite originating from S-type asteroid. The experiment resulted in obtaining gamma ray mass attenuation coefficient of S-type chondritic asteroid matter. Obtained results were analysed and final conclusions were formulated. Per unit mass, ordinary chondrites exhibit better gamma rays attenuation properties than any radiation shielding material contemporarily used in astronautics.
W niniejszej pracy poruszono zagadnienie pochłaniania promieniowania gamma w materiale budującym meteoryty należące do grupy chondrytów zwyczajnych, które pochodzą z planetoid typu S. Wysoce przenikliwe promieniowanie gamma powstaje w przestrzeni kosmicznej m.in. jako efekt oddziaływania pierwotnego promieniowania kosmicznego z ośrodkami materialnymi. Materiał pozyskany z małych ciał Układu Słonecznego może stanowić alternatywny budulec ciężkich osłon radiacyjnych statków kosmicznych, co uzasadnia prowadzenie badań nad pochłanianiem promieniowania jonizującego w meteorytach. Opisano tu eksperyment, do celów którego wykonano autorskiej konstrukcji stanowisko badawcze do analizy pochłaniania promieniowania jonizującego w materiałach sypkich. Przy pomocy tego stanowiska, wykorzystując radioaktywny izotop 60Co, określono masowy współczynnik absorbcji promieniowania gamma w sproszkowanym chondrycie zwyczajnym, a otrzymany wynik porównano z wartością obliczoną teoretycznie. W pracy przeprowadzono szczegółową analizę uzyskanych wyników i sformułowano wnioski płynące z przeprowadzonego eksperymentu. Na jednostkę masy, chondryty zwyczajne lepiej osłabiają promieniowanie gamma niż jakiekolwiek materiały osłonowe stosowane obecnie w astronautyce.
Źródło:: Acta Societatis Metheoriticae Polonorum; 2019, 10; 40-50
2080-5497
Pojawia się w:: Acta Societatis Metheoriticae Polonorum
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Mossbauer studies of Sołtmany meteorite - preliminary results
Autorzy:: Gałązka-Friedman, J.
Szlachta, K.
Powiązania:: https://bibliotekanauki.pl/articles/411513.pdf
Data publikacji:: 2012
Wydawca:: Polskie Towarzystwo Meteorytowe
Tematy:: Mössbauer spectroscopy
Sołtmany meteorite
Baszkowka meteorite
ordinary chondrites classification
Opis:: In Mossbauer spectra of the Sołtmany meteorite we identified four iron-bearing minerals: olivine, pyroxene, kamacite and troilite. The distribution of iron among these minerals is different in the Sołtmany meteorite from this distribution in the Baszkowka meteorite. As Sołtmany and Baszkowka meteorites are ordinary chondrites type L (both falls), differences in the distribution of iron over the four main iron-bearing mineral phases could be the basis for a new classification of L-type ordinary chondrites. Small amounts of taenite were also observed in the Sołtmany meteorite. The ratio of iron in kamacite and taenite in the Sołtmany meteorite was found to be about 3. No Fe3+ could be detected.
Źródło:: Meteorites; 2012, 2, No. 1-2; 73-77
2299-0313
2299-1220
Pojawia się w:: Meteorites
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Mössbauerowskie badania meteorytu Kuźnica
Mössbauer studies of Kuźnica meteorite
Autorzy:: Jakubowska, Martyna
Woźniak, Marek
Bogusz, Patrycja
Karwowski, Łukasz
Gałazka-Friedman, Jolanta
Duda, Przemysław
Powiązania:: https://bibliotekanauki.pl/articles/1830270.pdf
Data publikacji:: 2021
Wydawca:: Polskie Towarzystwo Meteorytowe
Tematy:: 4M method
Kuźnica
Mössbauer spectroscopy
Rumanová ordinary chondrites
meteorites
Opis:: Kuźnica meteorite was found in summer 2008 by an inhabitant of Częstochowa in the village of Kuźnica (Poland, voivodeship: Łódź, county: Pajęczano) in Poland. The finder, who is a passionate and collector of interesting stones, shared his find with the world only after a few years in the autumn of 2018. The found meteorite with a mass of 2.14 kg is an ordinary chondrite type H5. The degree of weathering on the surface is W2, inside W1. Currently, the meteorite is represented by 3 parts and two thin plates. The main mass is 2.037 kg, fragments are 13.7 g and 5.81 g. The found object was officially classified as a meteorite on 22th of November 2020. In this paper, we present the results of the Kuźnica meteorite measurements obtained by using the Mössbauer spectroscopy method. Mössbauer measurements of Kuźnica were performed at room temperature. The experimental spectrum was elaborated with “Recoil” program. Nine mineralogical phases were identified in the obtained Mössbauer spectrum: two doublets associated with olivine, two doublets associated with pyroxene, sextet associated with troilite, sextet associated with metallic phase identified as kamacite, doublet associated with iron hydroxides and two sextets associated with oxyhydroxides. The presence of a metallic phase or troilite in the test sample is convincing evidence of its extraterrestrial origin. These are mineralogical phases that can only arise in space conditions. Mössbauer spectroscopy allows for unambiguous identification of these mineralogical phases. In the standard 4M method, we use four basic phases to determine the type of ordinary chondrite: olivine, pyroxene, troilite and metallic phase, and we choose specimens in which the content of weathered phases does not exceed 7%. The Kuźnica meteorite is heavily weathered. The content of weathered phases is as much as 36.4%. Secondary minerals are a breakdown product of the metallic phase and to a lesser extent of the sulphide phase. Due to the strong weathering of the Kuźnica meteorite, we can modify the 4M method using only two basic phases: olivine and pyroxene. The analysis of the location of the Kuźnica meteorite on the figure of pyroxene vs. olivine dependence shows that it is ordinary chondrite type H. In this paper, the influence of the loss of the metallic and sulphide phases on the position of the Kuźnica meteorite on the figure of pyroxene/olivine vs. (pyroxene+metallic phase/(olivine+troilite)) was also checked. Weathering processes significantly transform many minerals. The resulting compounds often have parameters difficult to identify. However, difficulties in identifying secondary phases and their origins should not prevent an attempt to determine the type of meteorites using the 4M method.
Źródło:: Acta Societatis Metheoriticae Polonorum; 2021, 12; 31-40
2080-5497
Pojawia się w:: Acta Societatis Metheoriticae Polonorum
Dostawca treści:: Biblioteka Nauki

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