Leoncin – nowy polski chondryt LL4-6

• Authors: Łukasz Karwowski , Krzysztof Szopa

Title variants

EN

Leoncin – the new LL4-6 ordinary chondrite from Poland

• Languages of publication: PL

Abstracts

EN

In this study, the new ordinary chondrite LL4-6 from the Leoncin Community, Poland is reported. This meteorite was sold on Allegro, a Polish online e-commerce platform, to a person, who is member of the Meteoritic Society of Poland. The meteorite was sold in 2017, but originally the fall was in 2012. Finder of the meteorite from the Nowe Gniewniewice Village (Leoncin Community) claimed that the meteorite was still warm (the higher temperature was result after hit in the roof) after fall and made a whole in metal roof (which was repaired soon after the fall). For five years after fall of the meteorite, it stayed in the finder hands. The total known weight of the meteorite is 111.3 g. The main mass is in the M. Burski’s collection (~70 g). Two plates with the total mass 20 g are stored at the Earth Science Museum, Faculty of Natural Sciences, University of Silesia in Katowice, Poland. The meteorite is strongly brecciated. All clasts are rounded, reaching up to 1 cm in size. The matrix is very fine grained. The biggest as well as clasts are represented by complex olivine-feldspar chondrule. Numerous clasts do not have any chondrules or their fragments as well. The fusion crust of the Leoncin meteorite is typical, having porous and glassy (isotropic) the most external part. The glassy zone is rich in Cr-rich spinels, where relicts of unmolten olivines and pyroxenes are present. The next zone is so-called the black vein zone. The veins are represented my metallic phases or Fe sulphide. The most common mineral in the fresh meteorite is olivine, having Fo and Fa up to 69 and 31, respectively. Pyroxenes are characterised by a general chemical formulae as follow: Fs9.78–9.7 Wo44.77–44.2 En46.02–45.53. Almost all feldspars are represented by plagioclases (Ab83.5–86.76Or2.54–5.53An9.42–12.5). Metallic phases are mostly represented by kamacite, taenite and rare tetrataenite (the richest in Ni phase; 55.92–49.21 wt.%). Troilite, spinel, ilmenite, apatite and merrillite are also noted. Based on chemical composition of investigated minerals, the Leoncin meteorite can by classified as a LL ordinary chondrite. It has been confirmed by fayalite content (avg. 30.33%) as well as the forsterite content in pyroxenes (avg. 25.32%). Brecciating of the meteorite, the same mineral content of the chondrules and their matrix shows that the meteorite is an example of monomictic breccia. Metamorphic changes of the clasts, their quality, size and mineral content, together with the chemical composition of selected minerals, indicate the LL4-6 type of the meteorites. The Leoncin meteorite seems to be a regolith, that formed far from the collision place on the asteroid. This situation is confirmed by the limitation of gassy material only to the fusion crust and lack of shock changes in the minerals. The parent body might be similar to the 25143 Itokawa asteroid or has connection with the Flora family.

Keywords

EN

brecciated meteorite; monomictic breccia; new meteorite from Poland; ordinary chondrite LL4-6

Discipline

• GENETICS: GENETICS

• Publisher: Polskie Towarzystwo Meteorytowe
• Journal: Acta Societatis Metheoriticae Polonorum
• Year: 2020
• Volume: 11
• Pages: 31-44

Contributors

author

Łukasz Karwowski

• Instytut Nauk o Ziemi, Wydział Nauk Przyrodniczych, Uniwersytet Śląski w Katowicach

author

Krzysztof Szopa

• Instytut Nauk o Ziemi, Wydział Nauk Przyrodniczych, Uniwersytet Śląski w Katowicach

References

• Dunn T.L., Burbine T.H., Bottke W.F. Jr, Clark J.P., 2013, Mineralogies and source regions of near-Earth asteroids, Icarus, 222, s. 273–282.
• Fredriksson K., Nelen J.,Fredriksson B.J., 1968, The LL-Group Chondrites, w: L.H. Ahrens (ed.), Origin and Distribution of the Elements, International Series of Monographs in Earth Sciences, s. 457–466.
• Grady M.M., Pratesi G., Cecchi V.M., 2014, Atlas of Meteorites, Cambridge University Press, Cambridge.
• Hutchison R., 2006, Cambridge Planetary Science. Meteorites: A Petrologic, Chemical and Isotopic Synthesis, Cambrigde University Press, Cambridge.
• Norton O.N., 2002, The Cambridge Encyklopedia of Meteorites, Cambridge University Press, UK.
• de Pater I., Lissauer J.J., 2010, Planetary Science, Second edition, Cambridge University Press, Cambridge, 646 p.
• Rubin A.E., 1990, Kamacite and olivine in ordinary chondrites: Intergroup and intragroup relationships, Geochimica et Kosmochimica Acta., 54, s. 1217–1232.
• Stöffler D., Keil K., Scott E.R.D., 1991, Shock metamorphism of ordinary chondrites, Geochimica et Cosmochimica Acta, 55, s. 3845–3867.
• Tsuchiyama A., 2014, Asteroid Itokawa – A source of ordinary chondrites and a laboratory for surface processes, Elements, 10, s. 45–50.
• Van Schmus W.R., Wood J.A., 1967, A chemical-petrologic classification for the chondritic meteorites, Geochimica et Cosmochimica Acta, 31, s. 747–765.
• Wlotzka F., 1993, A weathering scale for the ordinary chondrites, Meteoritics, 28, s. 460.
• Woźniak M., Gałązka-Friedman J., Duda P., Jakubowska M., Rzepecka P., Karwowski Ł., 2019, Application of Mössbauer spectroscopy, multidimensional discriminant analysis, and Mahalanobis distance for classification of equilibrated ordinary chondrites, Meteoritics & Planetary Science, 54(8), s. 1828–1839.
• Woźniak M., Karwowski Ł., Gałązka-Friedman J., Duda P., Jakubowska M., Bogusz P., 2020, Metoda 4M – nowe zastosowanie spektroskopii mössbauerowskiej w klasyfikacji zrównoważonych chondrytów zwyczajnych, Acta Soc. Metheor. Polon., 11, s. 125–140.

• Document Type: article