Annama H chondrite—Mineralogy, physical properties, cosmic ray exposure, and parent body history. (11th April 2017)

• Record Type: Journal Article
• Authors: Kohout, Tomáš; Haloda, Jakub; Halodová, Patricie; Meier, Matthias M. M.; Maden, Colin; Busemann, Henner; Laubenstein, Matthias; Caffee, Marc. W.; Welten, Kees C.; Hopp, Jens; Trieloff, Mario; Mahajan, Ramakant R.; Naik, Sekhar; Trigo‐Rodriguez, Josep M.; Moyano‐Cambero, Carles E.; Oshtrakh, Michael I.; Maksimova, Alevtina A.; Chukin, Andrey V.; Semionkin, Vladimir A.; Karabanalov, Maksim S.; Felner, Israel; Petrova, Evgeniya V.; Brusnitsyna, Evgeniia V.; Grokhovsky, Victor I.; Yakovlev, Grigoriy A.; Gritsevich, Maria; Lyytinen, Esko; Moilanen, Jarmo; Kruglikov, Nikolai A.; Ishchenko, Aleksey V.
• Is Part Of: Meteoritics & planetary science. Volume 52:Number 8(2017)
• Page Start: 1525
• Page End: 1541
• Publication Date: 2017-04-11
• Subjects: Meteorites -- Periodicals; Planetology -- Periodicals; 523.4
• DOI: 10.1111/maps.12871
• Languages: English
• ISSNs: 1086-9379

Abstract

Abstract: The fall of the Annama meteorite occurred early morning (local time) on April 19, 2014 on the Kola Peninsula (Russia). Based on mineralogy and physical properties, Annama is a typical H chondrite. It has a high Ar‐Ar age of 4.4 Ga. Its cosmic ray exposure history is atypical as it is not part of the large group of H chondrites with a prominent 7–8 Ma peak in the exposure age histograms. Instead, its exposure age is within uncertainty of a smaller peak at 30 ± 4 Ma. The results from short‐lived radionuclides are compatible with an atmospheric pre‐entry radius of 30–40 cm. However, based on noble gas and cosmogenic radionuclide data, Annama must have been part of a larger body (radius >65 cm) for a large part of its cosmic ray exposure history. The 10 Be concentration indicates a recent (3–5 Ma) breakup which may be responsible for the Annama parent body size reduction to 30–35 cm pre‐entry radius.