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EN
An amoeboid olivine aggregates (AOA) are the refractory end-member of a family of fine-grained inclusions. They consist of masses of fine-grained (generally forsteritic) olivine crystals with other phases dispersed in between. The AOA are important components of carbonaceous chondrite and have been reported only from the unequilibrated Semarkona LL3.0 ordinary chondrite and examined by author equilibrated Sahara 02500 ordinary chondrite. The AOA’s are thought to represent solar-nebula condensates that experienced high-temperature annealing, but largely escaped melting. An amoeboid olivine aggregate found in the equilibrated ordinary Sahara 02500 chondrite has experienced weak planetary metamorphism resulting in equilibration and recrystallization of fine-grained olivine and albitic feldspar. The aggregate contains several fine-grained inclusions consisting of recrystallised fayalitic olivine, feldspar and minor amounts of metal, diopside, chromite, and apatite.
8
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Złudne nadzieje

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EN
Feliks Drzewiński was the professor of mineralogy and physics at Wilno (Vilnius) University. He was the author of the text-book of mineralogy – first in Polish. Meteorites also interested him. Drzewiński was the follower of the theory of the atmospheric origin of meteorites. The natural electricity of atmosphere was had the cause of their rise.
EN
From several years the fall of meteorite the Pułtusk is the object of interest again: they are this both theoretical works, as also field. Article presents fragment these workings and it contains the results of intimate works and searching.
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O nieznanej naturze meteorytów

51%
EN
The variable UV-fluorescence of minerals is well known, and this is attributed to some defects in crystallographic structure or some admixtures, e.g. REE elements. So far, UV-fluorescence has not been applied to describe the nature of meteorites. The plates of forty-five meteorites were examined in three simultaneous emission spectra under an epi-fluorescence microscope. Meteorites were characterized quantitatively according to twelve colours of fluorescence, arbitrarily identified. A numerical method of non-metric multidimensional scaling was used to put colour characteristics as well as the meteorites into an ordination space. Each colour characteristic carries its own information independent of the others. NWA 4039, Bilanga, Gujba and NWA 5437 are extremes in the ordination space. Sahara 560 and NWA 791 expressed very poor and very rich fluorescence, respectively. UV-fluorescence can be a good screening method to quickly distinguish space minerals with crystallographic defects and/or those which are contaminated by REE elements. In subsequent research, other more advanced methods will have to be used.
EN
Weathering processes of minerals which are presented in the Morasko meteorite are characterized by different speed of the secondary changes. The most resistant minerals for the alternations are phosphites (schreibersite, rhabdite, nickielphosphide) and carbides (cohenite) but also the mentioned phases show secondary fluctuation. Phosphites are changing into metallic, phosphorus free phases, which are similar to native nickel or avaurite (awaruitu) with very well visible modification of its crystal morphology. All phosphorus amount is introduced to secondary phosphates like vivianite. The carbides alternation processes occur in a different way than in case of phosphates. Carbon is free to the environment up to time, when the new phase is totally decomposed and replaced by hydroxyoxide of iron. Sometimes, the high-nickel metallic phases are also noted as the products of the weathering. All described mineral phases, that are resistant for secondary alternation might be indicators for high evolved meteoritic material in the Earth’s weathered rocks.
PL
Wietrzenie poszczególnych faz mineralnych, obecnych we fragmentach meteorytu Morasko, przebiega w różnym tempie. Za najbardziej odporne uznaje się fosforki (schreibersyt, rhabdyt, nickielphosphide) oraz węgliki (cohenit). Jednak po pewnym czasie również i te fazy ulegają rozpadowi. Z fosforków wyraźnie ubywa fosforu i przekształcają się one stopniowo w fazy metaliczne, zbliżone do taenitu lub awaruitu. Towarzyszy temu zmiana morfologii kryształów. Uwolniony fosfor wchodzi w skład wtórnych fosforanów typu wiwianit (vivianit). Węgliki zachowują się nieco odmiennie. Węgiel zostaje stopniowo uwalniany do środowiska a w dalszym etapie faza ta ulega całkowitemu rozpadowi przechodząc w wodorotlenki żelaza. Jednymi z ostatnich faz, które można dostrzec wśród wodorotlenków żelaza są wtórne fazy wysokoniklowe. Powyższe odporne na wietrzenie fazy, jako nieobecne na powierzchni Ziemi (z wyjątkiem krzemianów), mogą służyć identyfikacji meteorytowego pochodzenia silnie zwietrzałych skał.
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