Wyniki wyszukiwania - BazTech

1

Chondryt Antonin – pierwszy polski meteoryt ze zrekonstruowaną orbitą wokółsłoneczną. Raport z klasyfikacji i rejestracji oraz propozycje działań mogących wzbogacić kolekcję polskich meteorytów

Krzesińska Agata, Tymiński Zbnigniew, Maćkowska Roksana

Przegląd Geologiczny

|

2023

|

Vol. 71, nr 7

372--385

EN

On July 15, 2021, a bright fireball was registered over Poland and it led to a meteorite fall near the towns of Antonin and Mikstat, on the border of the Greater Poland and Lower Silesia voivodeships. Soon after registration of the bolide, a meteorite fragment was found. Observation of the fireball's trajectory helped to reconstruct the pre-atmospheric parameters of the meteoroid, such as the orbit inclination or eccentricity (Shrbený et al., 2022). Additionally, finding of the meteorite fragment enabled petrographic research and reconstruction of the thermal and collisional history of meteorite'sparent body. The Antonin meteorite is the first Polish meteorite with the reconstructed pre-atmospheric orbit and, atthe moment, one of only fifty in theworld. It is an L5 ordinary chondrite (Shrbený et al., 2022; Krzesińska, 2023). Here we present a report on the classification and registration process of the Antonin meteorite. Registration included measurements of cosmogenic isotope, necessary to prove the connection of the meteorite with the observed bolide. The specimen was found during the private expedition, so no direct proof existed for find in the predicted fall area. Cosmogenic isotope study allowed to assessing the time of meteorite fall, which matched the fireball event. Classification included petrographic and mineralogical analysis of the rock. The fall and find circumstances of Antonin allowed us to reflect on the lack of awareness of the Polish society regarding meteorites. Such unawareness is also seen when the whole collection of Polish meteorites is statistically analysed. We present such analysis at the end of the paper, and conclude that many meteorite falls in Poland must be unnoticed. Additionally, inability of citizens to recognize a meteorite, especially a chondrite, causes that many of these rocks remain unrecovered. The aim of this paper is to inspire the reader to pay attention to falls of meteorites, and to look for potential meteorite rocks. In final, we encourage the readers to get involved in activities of fireball networks and to take part in meteorite recovery trips.

2

Chondryt węglisty NWA 4446

Przylibski Tadeusz A., Blutstein Konrad, Łuszczek Katarzyna, Gruchot Joanna

Przegląd Geologiczny

|

2022

|

Vol. 70, nr 7

513--526

EN

The authors carried out petrographic, mineralogical, and chemical analyses (bulk chemical composition and microanalyses of mineral chemical composition) of NWA 4446 carbonaceous chondrite. NWA 4446 chondrite is classified as CV3, S2, W2. This meteorite is a rock fragment most likely from one of the C-type asteroids orbiting the Sun in the outer part of the asteroid belt. It represents the matter formed at the earliest stages of the formation of extrasola bodies in the solar system. As a result of the research, the authors documented a wider range of variation in the chemical composition of olivine crystals (Fa: 0.67-46.57 mol%) in the matrix and chondrules, and a much narrower range of variation in the chemical com- position of pyroxene crystals (Fs: 0.90–3.35 mol%) against the data used for the classification of the meteorite. The characteristics of the chondrules, ranging in size from 0.5 to more than 1 mm, allowed concluding that they constitute about 60% of the meteorite’s vol- ume, in which they form many structural and mineral varieties PO, POP, BO, PP and RP chondrules were observed. The remaining 40% of the chondrite volume is a matrix consisting of small crystals of pyroxenes, olivines, glass, as well as opaque minerals: sulphides, FeNi alloy, native copper and gold grains, carbonaceous substance, and compact CAIs. The mineral and chemical composi- tion of CAIs shows that their dominant mineral is melilite, accompanied by diopside and spinel. The chemical composition of spinel and diopside is very similar to their total chemical formulas, while the composition of melilite shows a significant sodium deficiency. Among the opaque minerals, one phase of the FeNi dominates - awaruite (Ni 3 Fe), and sulphides are represented by troilite (FeS) and mackinawite ((Fe,Ni) 9 S 8 ). Moreover, grains of native copper with an admixture of gold and grains of native gold with an admixture of platinum, nickel and copper with a size of several μm were identified. Taking into account the admixtures contained in the above-mentioned opaque minerals (mainly Co and Cu), the parent rock of the carbonaceous chondrite NWA 4446 can be considered to have been mineralized with Fe, Ni, Co and Cu ore minerals with the content of Au and Pt. This means that, we can expect deposits of native forms of the above-mentioned metals and sulphides on the parent bodies of carbonaceous chondrites of the CV group - C-type asteroids.

3

Potential extraterrestrial sources of lithium

Blutstein Konrad

Geological Quarterly

|

2021

|

Vol. 65, No. 4

195--203

EN

Extracting raw materials from extraterrestrial sources is a prerequisite for the expansion of our civilization into space. It will be necessary to acquire there practically all commonly used elements – including lithium. The most valuable source of this element currently appears to be lunar soil and rocks, especially K-rich rocks and breccias (>10 ppm of Li). Among the meteorites, the highest content of lithium is characterized by lunar mare basalts and gabbro, eucrites, Martian polymict breccia, nakhlites, howardites (>5 ppm), shergottites, chassignites, lunar anorthosites breccias, mesosiderites, ureilites (>2.5 ppm), diogenites, LL, angrites, H (>2 ppm), L, CM, CO, CV, EH, CI (>1.5 ppm), brachinites, aubrites, EL, CR (>1 ppm), CK and main-group pallasites (<1 ppm). This means that a potential extraterrestrial source of lithium can be the Moon, Mars, and the 4 Vesta minor planet considered as the probable parent body of HED meteorites.

4

Meteoryty, kratery uderzeniowe i inne ślady kosmicznej katastrofy w rejonie Moraska pod Poznaniem

Szczuciński Witold, Muszyński Andrzej

Przegląd Geologiczny

|

2020

|

Vol. 68, Nr 8

637--644

EN

About 5,000 years ago near Morasko (the district of the present-day city of Poznań, western Poland) the largest known iron meteorite shower in Central Europe took place. The evidence of that impact, documented so far, comprises numerous iron meteorite fragments distributed over an area of approximately 3 km2 and at least six meteorite impact craters with a maximum diameter of about 100 m. The present paper reviews the most recent findings related to the meteorite, craters, processes of their formation, as well as the environmental effects of the impact in the Morasko area. The most important findings, reported in this review cover: 1) the recognition of two new minerals in the meteorite: moraskoite and czochralskiite; 2) the identification and detailed analysis of the ejecta layer around the craters and underlying paleosoil providing evidence for the mid-Holocene age of the impact; 3) the numerical modelling constraining the range of likely physical properties of the impactor, e.g. the diameter of the projectile forming the largest crater and its landing velocity (c. 1.5 m and 10km/s, respectively);4) the studies of the nearby lake and peat deposits revealing restricted environmental effects of the impact. The Morasko craters field is currently one of the best-studied examples of small/moderate-sized meteorite impact in unconsolidated sediments.

5

Zawartość minerałów FeNi w chondrytach H jako wskaźnik zasobności pozaziemskich skał rudonośnych w wybrane metale

Blutstein K., Przylibski T. A., Łuszczek K.

Przegląd Geologiczny

|

2018

|

Vol. 66, nr 12

776--784

EN

Extraterrestrial resources should be the basic sources of materials for the development of humankind civilization in space as well as they could replace the Earth’s resources when they would be exhausted. They can be obtained from the planets, their moons or asteroids, primarily NEOs but also from the asteroid belt. This article presents the results of petrographic research on the content of FeNi minerals whose may be a source of iron and nickel, in H type ordinary chondrites: Pułtusk, Cher- gach, Tamdakht, Gao-Guenie andNWA 4555, which parent body is probably the 6Hebe. The results confirm that the volumetric abundance of FeNi minerals in H type chondrites is ca. 8%. Moreover, this study shows the reliability of the reflected-light optical microscopy for determination of ore mineral concentrations in extraterrestrial rocks with weathering grade W0. Taking into account the homogenous spatial distribution of metallic grains (proved by author’s microscopic observations) and knowing the amount of FeNi minerals in rocks with Hchondrite composition, the amount of potential FeNi resources on Hparent bodies can be calculated. It was estimated that the iron resources from Hebe’s FeNi minerals would cover 1.3 million years of terrestrial mining production whereas nickel resources would last for approx. 100 milion years. A small NEO asteroid like (143624) 2003 HM16 (2 km in diameter) has resources comparable with 15 months of mining iron production and over 100 years of nickel production at present rate.

6

Wyniki badań mineralogicznych i petrologicznych nowych okazów meteorytu Pułtusk w 150 rocznicę spadku

Przylibski T. A., Łuszczek K.

Przegląd Geologiczny

|

2018

|

Vol. 66, nr 6

368--378

EN

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.

7

Shock heterogeneity and shock history of the recently found ordinary Csátalja chondrite in Hungary

Kereszturi A., Fintor K, Gyollai I., Kereszty Z., Szabo M., Szalai Z., Walter H.

Geological Quarterly

|

2018

|

Vol. 62, No. 2

433--446

EN

Shock impact-produced mineral alterations in two thin sections of the recently found Csátalja H4 ordinary chondrite meteorite are compared. Peak positions of Raman and infrared spectra of mineral clasts show peaks shifted in wavenumber relative to unshocked reference minerals, and both peak shifts and FWHM values seem to correlate to each other. In the less shocked thin section (Csátalja-1) a more monomineralic and homogeneous composition indicate shock pressures of <15 GPa, while the more shocked Csátalja-2 indicates shock pressure in the 15–17 GPa range. The highest identified infrared peak position shifts range between –48 and +28 cm–1 with peak broadening between 60–84 cm–1 in the case of the feldspars, which, together with sulphide globules, were produced by the shock itself. Feldspar spectra could be detected only by FTIR spectroscopy, but in most cases (above the S3 shock level) the mixed type of the pyroxene-feldspar spectra (both peaks in the same spectra) is in agreement with the shock-produced secondary feldspars. These grains are located around crystalline borders, and probably formed by selective melting, due to shock annealing. In reconstruction of the shock history, an early fragmentation by a lower shock effect and a later increased shock level-related vein and melt pocket formation occurred, with subsequent shock annealing; temporal reconstruction of the shock event is possible only in part. The joint usage of Raman and infrared spectroscopy provided useful insights into the shock-produced changes and their spatial inhomogeneity, while shocked feldspar could be better detected by infrared than by the Raman method.

8

Thermal metamorphic evolution of the Pułtusk H chondrite breccia – compositional and textural properties not included in petrological classification

Krzesinska A. M.

Geological Quarterly

|

2016

|

Vol. 60, No. 1

211--224

EN

The thermal history that chondrites experienced on their parent body is an aspect of their petrological classification. However, in the classification scheme, metamorphic conditions are generally limited to the peak metamorphic temperature attained, while it is known that reconstruction of the genuine thermal evolution of any rock requires identification of various metamorphic factors, definition of the temperature-time path during metamorphism and characterization of the processes responsible for heating. Study of the brecciated Pułtusk H chondrite shows that the meteorite comprises both low and high petrologic type material and should be classified as a H3.8–6 chondrite. Based on the textures and mineral and chemical composition, the thermal metamorphic history of the breccia is reconstructed and it is shown to be inconsistent with the petrologic classification; the textural maturation and degree of compositional equilibrium in the meteorite do not correspond to the temperatures attained. The metamorphic conditions are shown to be a function of the primary composition of the accreted minerals and of two metamorphic phases, progressive and retrogressive. First, a prograde phase led to textural maturation and equilibration of the chemical composition of silicates and oxides. The peak metamorphic temperatures were at least ~700ºC for the type 3.8. and 4 material, and up to ~1000ºC in H6 clasts i.e., sufficient to locally give rise to partial melting. The following retrograde metamorphism led to compositional re-equilibration of minerals and textural re-equilibration of minerals with partial melts. The cooling rate during retrograde metamorphism down to at least ~700ºC was low, which allowed potassium feldspar to form patches in Na-plagioclase and pseudobrookite-armalcolite breakdown to form an association of ilmenite and rutile. The two-phase metamorphic evolution of the Pułtusk breccia was the most likely the result of impact heating, which affected the parent body in its very early history.

9

Lithological variations of sedimentary succession within a meteorite impact crater: Jwaneng South Structure, Botswana

Wendorff M., Master S.

Geology, Geophysics and Environment

|

2015

|

Vol. 41, no. 4

381--390

EN

The Jwaneng South Structure is a meteorite impact crater located in the Kalahari region of Botswana. The structure has the shape of a bowl 1.3 km in diameter and a maximum depth of 275 m in the centre. It was discovered by an airship-mounted full tensor gravity gradiometer and penetrated by nine vertical diamond drillholes. The crater is underlain by the Gaborone Granite (2785 Ma) and basalts of the Karoo Supergroup (182 Ma). The covering aeolian sediments of the Kalahari Group (Late Cretaceous-Recent) completely obscure the structure. A succession of the following lithofacies overlying authigenic in situ brecciated granite was intersected in the boreholes (from base to top): (i) allogenic heterolithic/oligomictic “fallback” and resedimented breccia (ii) sedimentary breccia and conglomerate with sand matrix; (iii) six intervals of carbonate sediments, with traces of evaporites and mudstone interbeds, which are interlayered with (iv) five intervals of sandstone and sedimentary breccia composed of granules, pebbles and cobbles, mostly of granite, embedded in a matrix of well-sorted medium-grained sand; (v) bioturbated, mostly massive sandstone rich in mud matrix (wacke), with locally preserved interbeds of mudstone and cross-bedded sandstone, and abundant root traces; (v) silcrete and calcrete that occur at the top of the succession. This lithological association suggests that deposition within the Jwaneng South meteorite impact crater took place in a playa lake surrounded by steeply-dipping talus piedmont fans. The depositional cycles were controlled by pronounced climatic oscillations. Wet periods are recorded by lithofacies (iii), which reflects intense supply of sand eroded from the Kalahari dune field surrounding the crater and coarse detritus derived from its rim and steep talus below. Dry intervals of high evaporation and fall of the lake level are reflected by lithofacies (iv). During the youngest wet period (v) the lake filled up with alluvia sands interbedded with muds, abundantly vegetated and homogenised by bioturbation. The silcrete and calcrete layer at the top of the succession is the product of pedogenic processes that affected the Kalahari Desert environment. An asymmetry of lateral distribution of the lithofacies (ii)–(iv) and the presence of sedimentary breccia redeposited into the marginal E (and NE) parts of the crater suggest an asymmetry of the crater depression and its coarse clastic rim, which may imply an oblique trajectory of the impactor approaching from the SW.

10

Charakterystyka petrograficzna skał pochodzących ze struktury impaktowej Gardnos, Norwegia

Jarmołowicz-Szulc K., Ilcewicz-Stefaniuk D., Stefaniuk M.

Biuletyn Państwowego Instytutu Geologicznego

|

2015

|

nr 464

43--48

PL

Krater meteorytu Gardnos znajduje się w Norwegii, ok. 125 km na północny zachód od Oslo. Cała struktura jest dobrze widoczna w terenie dzięki licznym odkrywkom brekcji impaktowych i utworów poimpaktowych występujących w okręgu o promieniu ok. 5 km. Główne typy skał impaktowych w rejonie krateru Gardnos to autochtoniczna brekcja z Gardnos oraz przykrywająca ją allochtoniczna brekcja impaktowa (suevit). W artykule omówiono petrografię tych skał. Brekcja z Gardnos jest brekcją lityczną, złożoną ze spękanych fragmentów skał, ale nie zawiera fragmentów stopu. Suevit jest brekcją polimiktyczną, zawierającą małe fragmenty zrekrystalizowanego stopu z klastami skał i minerałów.

EN

The crater of the Gardnos meteorite is located in Norway, about 125 km north-west of Oslo. The structure is well seen due to the outcrops of impact breccias and post-impact deposits that form a circle with a radius of about 5 km. Main types of the impact rocks in the Gardnos area are the autochthonous Gardnos breccia and its cover – allochthonous suevite breccia. The petrological characteristics of these rocks are presented. The Gardnos breccia is a lithic breccia, composed of fissured rock fragments, without melt components. The suevite is a polymictic breccia, built of small fragments composed of recrystallized melt and clasts of rocks and minerals.

11

The energy - based theory explaining dinosaur extinction and selectivity of Cretaceous - Tertiary extinction event coincided with a large meteorite impact

Gawle R., Czech Z.

International Letters of Chemistry, Physics and Astronomy

|

2013

|

Vol. 3

12-20

EN

This is our concise interdisciplinary energy theory explaining dinosaur extinction and the energy-based interpretation of the natural world. The theory proposes ideas which build on Luis Alvarez's impact theory by adding the energy-based mechanism underlying the mass extinction event-the final missing element to make the famous theory complete. Dinosaurs and other creatures of the Mesozoic Era differ from the commonly accepted image to which we are used.

12

Meteors and meteorite falls in Morocco

Ibhi A.

International Letters of Chemistry, Physics and Astronomy

|

2013

|

Vol. 12

28--35

EN

During the last eighty years, thirteen meteorite falls were recorded in Morocco, which ten are well documented and named Douar Mghila, Oued el Hadjar, Itqiy, Zag, Bensour, Oum Dreyga, Benguerir, Tamdakht, Tissint and Aoussred. It represent only 0.011 % of the Moroccan declared meteorites.The authenticated observed falls represent three types of different meteorites, eight ordinary chondrites (Four of type LL, three of type H and one of type EH), one carbonaceous chondrite and one Shergottite basaltic achondrites. The Morocco meteorite fall recovery rate, during the past eighty years, is low 0.11 falls per year on average per 2.11 km2 (or approximately one fall recovery per 10 year time interval).

13

Sołtmany meteorite

Karwowski Ł.

Meteorites

|

2012

|

Vol. 2, No. 1-2

15--30

EN

This paper presents the results of a mineralogical and petrological study of the Sołtmany meteorite, which fell on April 30, 2011 in northern Poland. The meteorite was found almost immediately after it fell and has been little altered by weathering. Sołtmany is not the only observed fall of an L6 chondrite over Europe in the past few years. The preceding fall of this type, Jesenice (Slovenia), was also witnessed in April of 2009. However, it was not until several weeks after the fall that the first specimen of Jesenice was found, whereas Sołtmany was collected after a few minutes and submitted for analysis within a couple of days. The author presents mineral and petrographic features and chemical characteristics of mineral phases in Sołtmany. The mineral components are represented by metallic phases (kamacite, taenite, tetrataenite, native copper), as well as chromite, olivine, low and high-calcium pyroxene, feldspar, chlorine-bearing apatite, and merrillite. This study also describes the texture of the meteorite and takes notice of a low number of preserved chondrules and the presence of oval chondrule like areas, which exhibit a metamorphosed, recrystallized texture. Sołtmany was classified as an L6 ordinary chondrite with a weathering grade of W0. A shock stage S2 was determined on the basis of undulose extinction and lack of planar fractures in olivine crystals.

14

Cosmogenic radionuclides in the Sołtmany (L6) meteorite

Laubenstein M., Giampaoli A., Janowski P., Mietelski J. W.

Meteorites

|

2012

|

Vol. 2, No. 1-2

45--51

EN

Cosmogenic radionuclides were measured in two specimens of the Sołtmany chondrite (L6) that fell on April 30, 2011. The first fragment (154.9 g) was measured 12 days after the fall and the second piece (120 g), 53 days after the fall. Both fragments were measured by means of non-destructive gamma ray spectroscopy. The first specimen was examined with an ultra-low background high purity germanium (HPGe) detector in a deep underground laboratory. A standard low-background HPGe detector was used to examine the second fragment in a ground level laboratory. Twelve cosmogenic nuclides were detected in the activity range of 0.030 m・Bq g–1 until 1.5 m・Bq g–1 Their activities place constraints on the exposure history of the meteorite and reflect the effect of solar modulation of galactic cosmic rays during the solar maximum. On the activities of expected radionuclides 60 Co (< 0.0075 m・Bq g–1) and 44 Ti (< 0.023 m・Bq g–1) only upper limits could be given. Sołtmany is part of a group of only 14 meteorites where 52 Mn (5.591 d half life) could be determined.

15

Chemical footprint of the solvent soluble extraterrestrial organic matter occluded in Sołtmany ordinary chondrite

Schmitt-Kopplin P., Harir M., Kanawati B., Tziozis D., Hertkorn N., Gabelica Z.

Meteorites

|

2012

|

Vol. 2, No. 1-2

79--92

EN

By characterizing organic molecules of extra-terrestrial origin included in the Sołtmany meteorite, we also present the first results of the non-targeted chemical analysis of the methanol soluble organic matter present in an L6 ordinary chondrite. The structural characterization by means of ultrahigh resolution Fourier transform ion cyclotron mass spectrometry (FT-ICR-MS) with electrospray ionization (ESI) in negative and positive modes demonstrated an unexpected and astonishing chemical diversity with several thousand mass peaks that could be converted into C, H, N, O, S, and P elemental compositions. Molecular signatures were typically those of considerably oxygenated CHO and CHOS molecular series of primarily aliphatic character. 1H nuclear magnetic resonance (NMR) spectroscopy confirmed the prevalent existence of pure and functionalized aliphatic spin systems of intermediate chain length (C3-4 units), oxygenated aliphatics and a considerable diversity of oxygenated aromatics in the proton-based abundance ratio near 24 : 2 : 1. Although only residual organic matter allegedly survives in highly thermally altered L6 chondrites, the physical protection of organic matter in microcavities and traps between mineral surfaces might have supported and governed the chemistry with an apparent recalcitrance of extraterrestrial organic matter (EOM). Future studies of the organic matter in ordinary chondrites and its composition and structure in various regimes of (e.g.) temperature, radiation, pressure, and water content could shed light on these meteorites’ formation and evolution.

16

Bulk chemical composition of Sołtmany chondrite

Przylibski T. A., Łuszczek K.

Meteorites

|

2012

|

Vol. 2, No. 1-2

31--37

EN

The authors examined the bulk chemical composition of the Sołtmany chondrite which fell on April 30th, 2011 in Northern Poland. Based on the analysis of 47 elements, it was concluded that Sołtmany is representative of L-type of ordinary chondrites. However, compared to the average values observed in other L-type ordinary chondrites, Sołtmany displays higher content of Ni, P, Cd, Pb, and As. The Ni and P content closely resembles typical values for H-type ordinary chondrites. Furthermore, Sołtmany displays other distinct properties including very low Zn content and lower contents of Mo and Zr than the average values found in other L-type ordinary chondrites. Consistent with other L-type ordinary chondrites, the absolute content of REE in Sołtmany is higher than that of CI-type carbonaceous chondrites while the REE trend lines for both Sołtmany and CI-chondrites are similar. Due to similar times of year of when both falls took place and the proximity of their strewn fields, the chemical composition of Sołtmany was compared with that of Jesenice, an L6 ordinary chondrite which fell on April 9th, 2009 in Europe. The analysis led to a conclusion that Sołtmany and Jesenice are not launch-paired. Nevertheless, even though they do not represent fragments of the same meteoroid, their origin on a common parent body (an asteroid – planetesimal) cannot be conclusively ruled out on the sole basis of their bulk chemical composition.

17

Microscopic studies of Al Haggounia 001 meteorite

Szurgot M., Polański K., Kosiński J. W.

Scientific Bulletin. Physics / Lodz University of Technology

|

2011

|

Vol. 32

65-74

EN

Elemental composition, mineral composition and microstructure of Al Haggounia 001 meteorite found in 2006 were studied by analytical electron microscopy. It was established that orthopyroxene dominated by enstatite (En89-S2Fs16-10Wo1-2), sodic plagioclase (Ab81-84An10-12Or4-5), graphite, and oxidized kamacite identified in the sample represent extraterrestrial minerals typical of enstatite meteorites. Chemical and mineral composition, and texture confirm that Al Haggounia is EL chondrite rather than aubrite, and terrestrial weathering significantly changed primary meteorite minerals.

PL

Badano skład pierwiastkowy, skład mineralny i mikrostrukturę meteorytu pustynnego Al Haggounia 001 znalezionego w Maroku w 2006 roku. Do badań wykorzystywano analityczną mikroskopię eiektronową. Ustalono, że zarówno skład pierwiastkowy, jak i skład mineralny, a także mikrostruktura tego nowego materiału pozaziemskiego potwierdzają jego przynależność do chondrytów enstatytowych klasy EL. Al Haggounia 001 uległ silnemu utlenieniu podczas długiego wietrzenia na Ziemi.

18

Nanometer-sized mineral grains and their genetic types in meteorites

Semenenko V. P., Girich A. L., Shkurenko K. O., Kychan N. V., Shyrinbekova S. N., Gorovenko T. M.

Meteorites

|

2011

|

Vol. 1, No. 1

13-19

EN

Three genetically different types of nanometer-sized mineral grains in meteorites can be distinguished based on literature and original data: (a) primitive condensates, (b) metamorphic grains, and (c) weathering products. The first of these groups were formed by condensation in a gas-dust nebula in either a presolar or solar environment. Metamorphic grains were formed as a result of thermal, shock or aqueous metamorphism on the meteorite parent bodies. The third type can clearly be characterized as terrestrial weathering products, which are generally found in meteorite finds and are rare or absent within meteorites recovered shortly after having fallen. Nanometric components are found predominantly within the fine-grained silicate material of primitive meteorites. It is suggested that enhanced accretional properties of nanometer-sized grains could be responsible for the primary accretion of condensed nanoglobules within a protoplanetary nebula. The nature of nanometer-sized inclusions of native W and native Ag originally discovered in the Krymka chondrite is preliminarily discussed.

19

Investigations of HaH 286 eucrite by analytical electron microscopy

Szurgot M., Polański K.

Meteorites

|

2011

|

Vol. 1, No. 1

29-38

EN

The elemental composition, mineral composition and microstructure of the HaH 286 eucrite found in Lybia in 2000 were studied by analytical electron microscopy. It was established that the mean elemental composition of HaH 286 and atomic and molar ratios: Fe/Mn = 34, Mg/Mg+Fe = 36, Na/Al = 0.066, and Ca/Al = 0.73 are typical of eucrites, and two main meteorite minerals have the mean composition: clinopyroxene En34Fs59Wo7 and plagioclase feldspar An88Ab12. Variations in the composition of pyroxenes and plagioclases are as follows: pyroxene En34-36Fs53-62Wo3-13 and plagioclase: An86-100Ab14-0. Pyroxene is represented by pigeonite and by orthopyroxene. Chromite, ilmenite and silica are minor minerals. The composition, atomic ratios and microstructure indicate that the HaH 286 meteorite is a pyroxene-plagioclase basaltic achondrite, a non-cumulate eucrite with the composition of plagioclase changing between anorthite and bytownite.

20

Diamonds in ureilites

Jakubowski T., Karczemska A., Kozanecki M.

Meteorites

|

2011

|

Vol. 0, No. 0

3-8

EN

The presence of diamonds in meteorites was confirmed for the first time in the Novo-Ureiureilite in 1888. Ureilites are a rare class of achondrites, often referred to as primitive achondrites. They are composed of olivine and pyroxene (pygeonite), as well as graphite inclusions often coexisting with diamonds. The following three main hypotheses of diamond origin in ureilites have been proposed: the HPHT process, graphite-to-diamond conversion under shock compression due to impact on the parent body (the most popular theory, as of the time of publication), and the CVD process in the solar nebula. The samples of all types of ureilites, from less shocked up to highly shocked, were examined using Raman Spectroscopy and Scanning Electron Microscopy. The results show the presence of diamonds in all of our samples. Of particular significance is the comparison of Raman spectra of diamonds and graphite phases of different ureilites.