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Wyszukujesz frazę "chondrite" wg kryterium: Temat


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Tytuł:
Northwest Africa 7915: A New approved LL5 chondrite from Morocco
Autorzy:
Brawata, M.
Kryza, R.
Jakubowski, T.
Przylibski, T. A.
Ćwiąkalski, J.
Łuszczek, K.
Powiązania:
https://bibliotekanauki.pl/articles/411506.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
chondrite
NWA 7915
Morocco
chondrule
chondrite chemistry
chondrite weathering
Opis:
A 415 g single meteorite was purchased in 2010 by T. Jakubowski from a dealer in Morocco. The meteorite was isometric in shape, ca. 8 cm in size, with distinct regmaglypts on the original ablated surface, and covered mostly in primary crust with one broken surface. The weight of the sample studied was 69 g. The meteorite is composed of several types of chondrules including porphyritic-Ol-Px, barred-Ol, radial-Px, granular and cryptocrystalline with distinct and diffused (not sharp) boundaries, and opaque grains and aggregates, enclosed in a very fine-grained matrix. The average compositions of minerals are: olivine (both in chondrules and matrix) − Fo70.4Fa29.1Te0.5, pyroxenes, represented by Mg-Fe (Ca-poor) orthopyroxene (and minor clinopyroxene?) − En73.9Fs24.1Wo2.0, feldspars (small in the matrix and in barred chondrules), with An12-37, and Or~3-4, taenite − Fe 70.80, Ni 25.50 and Co 1.67 wt. %, troilite − Fe0.98S1.00, chromite (Fe2+ 0.96Mg0.12Mn0.01Zn0.01) (Cr1.52Al0.23Fe3+ 0.02Ti0.10Si0.02)O4; altered accessory minerals including apatite and iron-rich secondary phases have also been identified and analyzed. The meteorite is of petrologic type 5, as evidenced by the observed recrystallization of the matrix, relatively good preservation of the chondrule structures, homogeneous composition of olivine and pyroxene, and the presence of only secondary small feldspar grains. The shock stage, S2, is based on the presence of undulatory extinction and irregular fractures in olivine crystals. The weathering grade, W3, is confirmed by the observation that kamacite is totally altered into secondary iron phases, whereas Nirich taenite, and troilite are only partly weathered. The specimen shows many bulk- and mineral-chemical parameters corresponding, mostly, to the LL chondrite group (e.g., Fe/SiO2 0.49, SiO2/MgO 1.62, Fa in olivine 29.05). However, concentrations of several other elements, including REE, are not fully consistent with the average values for the LL ordinary chondrites. Apparently, the parent body of the studied NWA 7915 meteorite was depleted in Dy, Tm, and Yb, compared to typical LL-type ordinary chondrite parent bodies. Also, relatively high concentrations of other elements, including Ba and Sr, have been measured, which may result from terrestrial weathering in hot desert conditions. The meteorite has been classified as LL5 ordinary chondrite, S2, W3, and registered in the Meteoritical Society database as NWA 7915. The type specimen is deposited in the Mineralogical Museum of the University of Wrocław.
Źródło:
Meteorites; 2014, 3, No. 1-2; 45-58
2299-0313
2299-1220
Pojawia się w:
Meteorites
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wyniki badań mineralogicznych i petrologicznych nowych okazów meteorytu Pułtusk w 150 rocznicę spadku
Results of mineralogical and petrological research of new samples on the Pułtusk meteorite at the 150th anniversary of the fall
Autorzy:
Przylibski, T. A.
Łuszczek, K.
Powiązania:
https://bibliotekanauki.pl/articles/2075816.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Pułtusk
meteoryt
chondryt
zwyczajny chondryt
chondryt H5
meteorite
chondrite
ordinary chondrite
H5 chondrite
Opis:
One of the largest observed stone meteorite shower in the history of mankind on Earth took place on Thursday evening on January 30, 1868, about seven o’clock near Pułtusk in Poland. Despite the 150th anniversary of the fall of chondrite officially classified as Pułtusk H5 with a shock stage S3 there is still little published data on the chemical composition of minerals of this chondrite as well as its petrological characteristics in the literature. The authors carried out mineralogical and petrological research that will help a little to fill this gap in knowledge about the Pułtusk chondrite. Meteorite specimens found by Piotr Kuś in 2015 and investigated by the authors are undoubtedly part of the Pułtusk fall of January 30, 1868. They can be classified as ordinary chondrite H5, S2,W2. The authors stated that the studied rock is characterized by a varied shock level -from S1 to S2/3, as well as it contains chondrules of the chromite-plagioclase unequilibrated rock. In the composition of the examined fragment of Pułtusk chondrite, the authors identified silicates: olivine, diopside, bronzite and clinohyperstene, and oligoclase, oxides: chromite (and spinel), sulfides: troilite, FeNi alloy mineral phases: kamacite and taenite, as well as phosphates: merrilite and apatite. The chemical composition of olivine crystals as well as low- and high-Ca pyroxenes crystals and plagioclase crystals (about the composition of oligoclase) confirms that the examined specimen comes from the Pułtusk fall and it is a rock that should be classified as a petrographic type H5.
Źródło:
Przegląd Geologiczny; 2018, 66, 6; 368--378
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new classification of Nyirábrany, an ordinary chondrite from Hungary
Autorzy:
Mészáros, M.
Kereszturi, A.
Ditrói-Puskás, Z.
Powiązania:
https://bibliotekanauki.pl/articles/411486.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
chondrite
classification
L and LL chondrites.
Opis:
The Nyirábrany meteorite is an ordinary chondrite from Hungary that fell in 1914 and, to date, has been studied very little. The aim of this work was to carry out a more detailed examination of this meteorite (using optical polarization microscope, energy dispersive X-ray spectroscopy and Raman micro spectroscopy) and re-investigate its previous classification as an LL5 type ordinary chondrite, moreover to complete its classification with a shock stage and a weathering grade. Our new results indicate that Nyirábrany could be a transition type between the L and LL chondrites. The main mineral phases of Nyirábrany are olivine, pyroxene and opaque minerals (e.g. Fe-Ni metal, troilite, chromite), minor constituents are plagioclase, Cl-apatite, cristobalite and glass. The Fe-Ni metal content (1.32 vol%) of Nyirábrany is typical of the LL group, the Fa content of olivines (26.71 mol%) is between the range of the L and LL types, while the Fs-content of the low-Ca pyroxenes (20.51 mol%) is typical of the L-chondrites. Chondrules appear in different sizes, mineral compositions and textures. The textural and mineralogical features (e.g. mostly homogeneous silicate minerals, dominance of clinopyroxenes, recrystallized matrix, well-defined chondrules) indicate petrological type 4-5 for Nyírábrány. The shock stage and the weathering grade of this meteorite were examined for the first time. On the basis of the observed optical and textural features of the olivine grains (e. g. sharp optical extinction, irregular and planar fractures) Nyirábrany has an S2 shock stage. About 30–40% of the opaque phases are affected by oxidation, which shows a W2 weathering grade.
Źródło:
Meteorites; 2014, 3, No. 1-2; 19-32
2299-0313
2299-1220
Pojawia się w:
Meteorites
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kopalne ordowickie chondryty – przegląd danych
Fossil ordovician chondrites – a review
Autorzy:
Brachaniec, Tomasz
Brom, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/1033024.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Ordovician
Osterplana
Sweden
chondrite
fossil meteorite
Opis:
The largest group of fossil meteorites are L type chondrites, found in the Middle Ordovician limestones in Sweden. Until now, 101 specimes were discovered. Probably, they come from collisions in the asteroid belt. They are completely altered, except the chromite grains.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2015, 6; 23-25
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skład chondrytów zwyczajnych a potencjalne surowce pasa planetoid
Composition of Ordinary Chondrites and Potential Natural Resources of Asteroid Belt
Autorzy:
Łuszczek, Katarzyna
Przylibski, Tadeusz A.
Powiązania:
https://bibliotekanauki.pl/articles/1032729.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Fe-Ni alloy
asteroid
asteroid belt
chondrite
extraterrestrial resource
meteorite
meteorites
natural resource
ordinary chondrite
troilite
Opis:
In this article the authors present a simple method of determining the content of selected metal raw materials (Fe, Ni, Co) on the parent bodies of ordinary chondrites. Thanks to the use of planimeter for measuring, under microscope, polished slices of meteorites, it is possible to estimate quite accurately the proportion of these metals in the parent bodies of meteorites, i.e. on asteroids. When it comes to analysing a large number of polished slices, these results will be most likely comparable to much more expensive results of chemical tests conducted on meteorites. Based on the analysis of 16 thin polished sections and polished slices of 11 ordinary chondrites, the authors found out that the highest content of Fe, Ni and Co ore minerals, reaching 10,06% of the total volume, can be found in ordinary chondrites from group H. For ordinary chondrites from groups L and LL, it makes 3,86% and 3,93% of the volume respectively. Employing the results of chemical analyses available in literature sources, the authors also estimated the size of Fe, Ni and Co resources for several selected asteroids. These bodies contain higher concentrations of iron, nickel and cobalt than terrestrial deposits (those found in the earth’s crust). The total content of Fe on parent bodies of even the most deficient in metals group LL of ordinary chondrites is about twice as high as that in the earth’s crust. Cobalt occurs on parent asteroids of ordinary chondrites in concentrations 15–24 times as high as those in the earth’s crust, and the concentrations of Ni are 100–180 times as high as those in the earth’s crust. The contents of these metals on parent asteroids of ordinary chondrites are also several times as high as those in currently extracted deposits in the earth’s crust. Taking into account the mean annual terrestrial production of these metals, the authors have estimated that a parent asteroid of ordinary chondrites with the size between 433 Eros and 6 Hebe could satisfy our need for Fe, Ni and Co for the nearest several million to dozens of billion years. Considering the fact that asteroid belt contains plenty of such objects, and as many asteroids built chiefly of Fe-Ni alloy, one should regard this section of the Solar System as a practically inexhaustible source of metal raw materials. The prospect of their exploitation is probably much nearer than we can currently imagine.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2011, 2; 92-111
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spadki meteorytów w 2017 roku. Okoliczności i obserwacje
Meteorite falls in 2017. Circumstances and observations
Autorzy:
Żmija, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/1033123.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
bolide
chondrite
eucrite
fireball
meteor
meteorite
meteorite fall
summary
Opis:
This scientific paper is a summary of the meteorite falls in 2017: Broek in Waterland (Holland), Tres Irmaos (Brazil), Serra Pelada (Brazil) and Kheneg Ljouâd (Morocco). The study also includes a section about unconfirmed falls, such as Puya Medio (Colombia), Mukundpura (India), Crawford Bay (Canada) and Sadiya (India). The vast majority of these specimens is ordinary chondrites of the L and LL groups. Only Serra Pelada meteorite turned out to be eucrite and Mukundpura is suspected to be carbonaceous chondrite. The author collects and organizes basic information about these findings and compares the latest data with statistics from previous years. The description of the circumstances of finding meteorites are brief and maintained in the popular-scientific tone. The text also includes a set of fireballs and bolides that could end with a meteorite fall. Among them is also a bolide that was visible from Poland. The thesis resembles the criteria for dividing meteors and notes the differences in their naming. It is extended by analogies and comparisons that make possible to look at the issues from different perspectives: from the statistical, through the media, to the historical one.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2018, 9; 187-205
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spadki meteorytów w 2018 roku. Okoliczności i obserwacje
Meteorite falls in 2018. Circumstances and observations
Autorzy:
Żmija, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/1033142.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
achondrite
bolide
chondrite
fireball
meteorite
meteorite fall
summary
superbolide
Opis:
This scientific paper aims to systematize knowledge about the circumstances of meteorite falls in 2018. Eight of them were officially confirmed by The Meteoritical Society: Hamburg (USA), Ablaketka (Kazakhstan), Aba Pan (Nigeria), Mangui (China), Ozerki (Russia), Renchen (Germany), Gueltat Zemmour (Morocco), Komaki (Japan). Seven more have not yet been classified: Central Kalahari (Botswana), Glendale (USA), Benenitra (Madagascar), Bhakkar (Pakistan), Ghadamis (Libya), Elkouran (Morocco) and meteorite fall from the Sahara Desert. It turns out that the most numerous group of meteorite falls in 2018 were L6 chondrites. There were no iron or stony-iron falls. The author collected information from many different sources. He analyzed entries in the MetBull catalog, publications in social media and press reports in order to compare them with official data from previous years. In this way, he tries to prove that although the circumstances of each meteorite fall are different, coherent conclusions can be drawn from them, and these can help meteorite researchers, for example, in verifying eyewitness accounts.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2019, 10; 199-221
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spadki meteorytów w 2019 roku. Okoliczności i obserwacje
Meteorite falls in 2019. Circumstances and observations
Autorzy:
Żmija, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/1033169.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
bolide
carbonaceous
chondrite
fireball
meteor
meteorite
meteorite fall
summary
Opis:
In 2019 two meteorite showers occurred on Earth, which ended with the fall of hundreds of fragments in Cuba and Costa Rica. Apart from them, meteorites with a total weight of probably less than 10 kg landed in Algeria, Morocco, Iran, India, and Germany. This work is another summary of the year in terms of meteorite falls. It includes information on the circumstances of these phenomena and their scientific consequences. The author collected information from many sources, especially the media and meteorite hunters, to describe in a brief form how the meteorites fell last year. The purpose of his work is to gather basic and proven knowledge, which can serve as an inspiration to further explore the history of meteorites, own meteorite hunting, and draw the attention of researchers to interesting falls in distant regions of the world.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2020, 11; 141-157
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sprawozdanie z poszukiwań meteorytów w Oslo
Search report of meteorites in Oslo
Autorzy:
Tymiński, Zbigniew
Stolarz, Marcin
Kubalczak, Tomasz
Burski, Maciej
Zaręba, Paweł
Holst, Martin
Bilet, Morten
Powiązania:
https://bibliotekanauki.pl/articles/1032969.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Oslo meteorite
chondrite
hammer
hunting for meteorites
meteorite fall
meteorite strewnfield
meteorites
Opis:
A piece of a meteorite that had crashed through the roof of a cottage house was find in the central Oslo quarter Rodelřkka at the beginning of March 2012. Some days later the second discovery in the melting snow of Ekebergsletta hilltop plateau triggered the hunting for meteorites in almost all sides of Oslo. The pieces of third meteorite broken by cars and spread out by snowplow was discovered on the asphalt road side by Maciek Burski, the member of Polish Meteoritical Society. Later on the missing fragments of the Maciek’s most east find was collected by Meteoritical Section members of Comet and Meteor Workshop (PKiM) with the help of local meteoritical authorities. The total mass of this unobserved fall is 6.22 kg in five pieces spread out in the eight km-long strewnfield with 200 g and 4.65 kg meteorites on the opposite ends. The Meteorite is not classified yet but unofficial information is “breccia H3-4”.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2013, 4; 108-114
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermophysical properties of the Sołtmany meteorite
Autorzy:
Szurgot, M.
Wach, R. A.
Przylibski, T.A.
Powiązania:
https://bibliotekanauki.pl/articles/411496.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
chondrite
differential scanning calorimetry (DSC)
specific heat capacity
thermal capacity
thermal diffusivity
thermal conductivity
Opis:
Bulk density, porosity and thermophysical properties of the Sołtmany meteorite have been determined. The mean bulk density of the meteorite is 3.475‧103kg/m3, mean bulk density of the crust is 4.3‧103 kg/m3, grain density 3.71‧103 kg/m3, and porosity 6.4 ±} 0.4%. Mean specific heat capacity determined by DSC in temperature range between 223 and 823 K increases from 595 to 1046 J/(kg‧K), and is equal to 728 J/(kg‧K) at room temperature. Specific heat capacity of various samples is in the range 705–769 J/(kg‧K) at room temperature. Thermal capacity of Sołtmany chondrite is equal to 2.53‧106 J/(m3‧K), thermal diffusivity (1.5–1.8)‧10-6 m2/s, and thermal conductivity 3.9–4.5 W‧m–-1‧K-1at room temperature. Differential scanning calorimetry revealed two reversible phase transitions in the Sołtmany’s troilite: α/β transition at 423 K, and β/γ transition at 596.6 K.
Źródło:
Meteorites; 2012, 2, No. 1-2; 53-65
2299-0313
2299-1220
Pojawia się w:
Meteorites
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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