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Evolution of the Dislocation Structure of Iron Meteorite

Osuch W., Błoniarz R., Michta G., Suliga I.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

485--492

EN

The state of the dislocation substructure of meteorite in which the history of phenomena accompanying the meteorite during its passage through the Earth’s atmosphere is recorded remains unused. The main goal of the presented work is a comprehensive analysis of the dislocation structure of the iron meteorite from the Morasko reserve (Poland, Wielkopolska Voivodeship) by TEM methods to determine the conditions and mechanism of its formation. The work is cognitive in the field of phenomena related to the destruction and deformation of the material in extreme conditions: space and terrestrial space. It can also be useful in the research on the creation of the material with specific mechanical properties, as well as a unique reference material for earth experiments with low-temperature deformation, high-speed deformation, recrystallization processes with short thermal pulses and structure relaxation in conditions of very long time periods.

2

Geochemistry and growth morphology of alkali feldspar crystals from an IAB iron meteorite : insight into possible hypotheses of their crystallization

Słaby E., Karwowski Ł., Majzner K., Wirth R., Muszyński A., Birski Ł., Simon K., Domonik A., Moszumańska I., Orłowski R.

Annales Societatis Geologorum Poloniae

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2017

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Vol. 87, No. 2

121--140

EN

Alkali feldspar crystals have been recognized in the troilite-graphite nodules of the Morasko IAB iron meteorite. Their chemical, microtextural and structural properties were studied using electron microprobe analysis (EMPA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), transmission electron microscopy (TEM) and Raman spectroscopy. The feldspars occur as perthitic or antiperthitic intergrowths, whereas the albite lamellae are perfectly twinned. The structural properties reveal intergrown phases with fairly disordered patterns. The electron microprobe analyses demonstrate that the intergrown phases are mainly rich in sodium or potassium, resulting in compositions that are close to those of albite or orthoclase. The compositions, calculated on the basis of a segmented perthite-antiperthite image, showed that the Or-to-Ab proportions in the homogenized crystals were almost 0.3:0.7, thus indicating that the anorthoclase crystallized under high-temperature conditions. Two hypotheses of crystal formation could account for these characteristics: crystallization from a melt or from a metasomatic solution. Relics with evidence of metasomatic replacement of former minerals were not found. Accordingly, this work focuses on arguments that support the other hypothesis. Large ion lithophile elements (LILEs, e.g., Ba, Sr, Rb, LREE, Pb, and Ga) were used to track the origin of the crystals. Their concentrations indicate crystallization from a parent melt strongly depleted in LILEs. Alkali feldspar is commonly a product of a highly differentiated melt. However, highly differentiated melts are typically enriched in LILEs, which here is not the case. The melt that crystallized the feldspar cannot be related to impact-induced partial melting of the chondritic material alone. The derived melt probably was contaminated by silica-rich target material during interaction between the IAB projectile and the target material and was accompanied by metal and sulphide melts that were both immiscible with a silicate melt.

3

Dating the Morasko meteorite fall by natural thermoluminescence of the fusion crust

Fedorowicz S., Stankowski W. T. J.

Geologos

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2016

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Vol. 22, No. 3

251--258

EN

The date of fall of the Morasko iron meteorite was determined by means of thermoluminescence measurements of the fusion crust and related local materials. Three small pieces, commonly referred to as ‘shrapnel’, were used. The results obtained are 4.5–5.0 ka, which is in good agreement with previous estimates of 4–6 ka on the basis of radiometric, dosimetric and palynological methods.

4

A Preliminary Study On the Electrical Signatures of Some Iron and Stony Meteorites and Their Dependence On Nickel Content

Nabawy B. S., Rochette P.

Acta Geophysica

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2016

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Vol. 64, no. 5

1942--1969

EN

The present study is considered as an exploratory study of electrical properties of meteorites at variable current frequencies, called the electrical signature. The electric resistivity has been measured at different frequencies, varying between 1 and 100 KHz for some iron meteorites (Mundrabilla and Gibeon meteorites), stony meteorite samples (NWA 869, NWA 7629 and Ghubara) and Fe-Ni alloys, of known Ni concentration, which have been prepared and used as standards to be compared with the studied meteorites. In addition, SEM studies supported by EDX technique have been applied. The SEM and EDX displays enabled us to obtain the chemical composition and internal structural fabrics of the studied samples. Porosity and density (bulk and grain densities) have also been measured for both types of meteorites. Porosity values of the studied meteorites are very low (∅ ≤ 3%) and correspond to micro vugs and cracks. The grain density of non-weathered samples varies from 3.48 g/cm3 for the stony meteorites to 7.91 g/cm3 for the iron meteorites. The obtained electrical signatures are diagnostic for each type and can be used to detect quantitatively the concentration of Ni. The electrical signature of stony meteorites is much simpler than that of iron meteorites, and simpler signatures have been obtained at higher Ni concentrations.

5

Meteoryt żelazny z krateru Kamil. Pustynia Zachodnia. Egipt

Pawlikowski M., Wróbel M.

Auxiliary Sciences in Archaeology, Preservation of Relics and Environmental Engineering

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2014

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nr 17

1--8

PL

Wykonano badania mineralogiczne i chemiczne meteorytu z krateru Kamil zlokalizowanego na pustyni Zachodniej Egiptu przy granicy z Sudanem. Badania prowadzono z wykorzystaniem metod: XRD,SEM i EDS.

EN

Mineralogical investigation of iron meteorite from West Desert (Sahara) were performed using XRD, SEM and EDS methods.