Meteorite from Ybbsitz

The Ybbsitz meteorite is a meteorite discovered during geological mapping work near Ybbsitz in western Lower Austria (location: 14 ° 54 ′ 25 ″ E, 47 ° 56 ′ 13 ″ N ). The 14.6 kilogram H4 chondrite was located on the northern slope of the Prochenberg at 650 m above sea level. A. The main piece of the meteorite weighing 11.9 kilograms is now in the Natural History Museum in Vienna . 47.936944444444 14.906944444444 650

Find history

For the geological revision of the Austrian map 1: 50,000 by the Federal Geological Institute (GBA), mapping work was carried out on the Prochenberg near Ybbsitz in the western Lower Austrian Alpine foothills on September 17, 1977 . In order to delimit various geological units in this area, a more detailed inventory of the local rock was carried out . A piece of rock that was not standing stood out because of its color and weight. The dark color suggested an ultrabasic rock , which, however , was incompatible with the geological conditions at the site, which is located in the outcrop of the Frankenfels and Lunzer nappes of the Northern Limestone Alps . In order to be able to carry out a closer determination in the laboratory, a sample was knocked out of the piece and a thin section was made from it.

The subsequent examination of the thin section at the University of Salzburg in 1979 quickly revealed its extraterrestrial origin. The fracture surfaces of the piece found in Ybbsitz suggested that the find was only a fragment of a formerly larger body that must have disintegrated into at least three larger pieces before the impact . A search in the vicinity of the point of impact for the other parts of the meteorite was unsuccessful. The find made headlines in newspapers.

On June 2, 1980, the ORF broadcast a report about the Ybbsitz meteorite in the program “ Wissen aktuell” . The main piece of the Ybbsitzer meteorite was given as a gift by the Federal Geological Institute to the Natural History Museum in Vienna in January 1981 , where it has since been publicly accessible in its meteorite collection . Lifelike casts can be found in the Federal Geological Institute and in the market town of Ybbsitz. At the time of the discovery, it was the sixth meteorite found in what is now Austria, and only the second without a case observation.

Fall time and age

There are no reliable witness reports about the time of the case. Based on the extent of the weathering condition of the meteorite surface, a fall event a few decades ago before the discovery was originally estimated. Vague indications from the population reporting bright appearances suggest a fall time in the 1950s. By surface exposure dating and analysis of cosmogenic radionuclides was derived that the meteorite fell at least before the 1970th The Ybbsitzer meteorite probably broke out of the mother body in a single collision in the asteroid belt . This event took place around 1.5–1.7 million years ago.

Mineral chemistry and petrology

The Ybbsitzer meteorite is classified as H-chondrite due to its mineral composition consisting mainly of olivine and pyroxene . The content of kamacite contained in the meteorite corresponds to this allocation . The chondritic structure with a clear distinction between matrix and chondren in connection with the relatively uniform chemistry of olivines and pyroxenes enables the meteorite to be assigned to petrological class 4. The Ybbsitzer meteorite is therefore classified in the specialist literature as H4 chondrite .

Web links

Photo of the largest fragment of the meteorite in the exhibition of the Natural History Museum Vienna

literature

Erich Dolezal: The meteorite find from Ybbsitz. Universum, Austrian monthly magazine for nature, technology and business. Volume 35 (1980), pp. 284-288.
Wolfgang Schnabel: The Ybbsitz meteorite. Waidhofner Heimatblätter. 7th year (1981), pp. 25-31, DNB 012932833 , OCLC 2659124 .

Individual evidence

↑ ^a ^b Wolfgang Schnabel: History of discovery and discovery of the Ybbsitz meteorite. Annals of the Natural History Museum. 87th Volume (1985), pp. 1-9 ( PDF ).
^ Gerd Heusser: Cosmogenic radionuclides in the chondrite Ybbsitz. Annals of the Natural History Museum. 87th Volume (1985), pp. 61-64 ( PDF ).
↑ Peter Signer, Rolf Sarafin, Ludolf Schultz, Hartwig Weber, Rainer Wieler: rare gases and ¹⁰ Be in Ybbsitz; Notes on the history of the meteorite. Annals of the Natural History Museum. 87th Volume (1985), pp. 53-60 ( PDF ).
^ F. Brandstätter, E. Kirchner, A. Kracher, G. Kurat: Der Meteorit von Ybbsitz: Petrologie und Mineralchemie. Annals of the Natural History Museum. 87th Volume (1985), pp. 11-20 ( PDF ).

[Schnabel1985-1] Wolfgang Schnabel: History of discovery and discovery of the Ybbsitz meteorite. Annals of the Natural History Museum. 87th Volume (1985), pp. 1-9 ( PDF ).

[2] Gerd Heusser: Cosmogenic radionuclides in the chondrite Ybbsitz. Annals of the Natural History Museum. 87th Volume (1985), pp. 61-64 ( PDF ).

[3] Peter Signer, Rolf Sarafin, Ludolf Schultz, Hartwig Weber, Rainer Wieler: rare gases and ¹⁰ Be in Ybbsitz; Notes on the history of the meteorite. Annals of the Natural History Museum. 87th Volume (1985), pp. 53-60 ( PDF ).

[4] F. Brandstätter, E. Kirchner, A. Kracher, G. Kurat: Der Meteorit von Ybbsitz: Petrologie und Mineralchemie. Annals of the Natural History Museum. 87th Volume (1985), pp. 11-20 ( PDF ).