Meteorite terrestrial ages in Oman based on gamma spectrometry and sediment dating, focusing on the Ramlat Fasad dense collection area

Rosén, Åke V.; Hofmann, Beda A.; Preusser, Frank; Gnos, Edwin; Eggenberger, Urs; Schumann, Marc; Szidat, Sönke (2021). Meteorite terrestrial ages in Oman based on gamma spectrometry and sediment dating, focusing on the Ramlat Fasad dense collection area. Meteoritics & planetary science, 56(11), pp. 2017-2034. Meteoritical Society at the University of Arkansas, Dept. of Chemistry and Biochemistry 10.1111/maps.13758

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We combine the search for young meteorites in the Omani-Swiss collection (~1140 fall events collected 2001–2018) using 22Na and 44Ti with luminescence and 14C sediment ages from the Ramlat Fasad (RaF) dense collection area (DCA) of Oman to obtain combined terrestrial ages and maximum accumulation times, and test whether the proportion of young meteorites is consistent with the models of meteorite flux and weathering. Gamma-ray spectrometry data for 22Na show that two (0.17%) of the meteorites in the collection fell during the 20 yr preceding this study, consistent with the rates of meteorite accumulation. In the RaF DCA, meteorites are found on Quaternary to Neogene sediments, providing constraints for their maximum terrestrial ages. 44Ti activities of the RaF 032 L6 strewn field found on deflated parts of active dunes indicate an age of 0.2–0.3 ka while dune sand optically stimulated luminescence ages constrain an upper age of 1.6 ka. Extensive sediment dating using luminescence methods in the RaF DCA area showed that all other meteorite finds were made on significantly older sediments (>10 ka). Dense accumulations of meteorites in RaF are found on blowouts of the Pliocene Marsawdad formation. Our combined results show that the proportion of meteorites with low terrestrial ages is low compared to other find areas, consistent with the previously determined high average terrestrial age Oman meteorites and significantly older than suggested by models of exponential decay. Oman meteorites may commonly have been buried within dunes and soils over extended periods, acting as a temporary protection against erosion.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP)
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Rosén, Åke Viktor; Hofmann, Beda Anton; Eggenberger, Urs and Szidat, Sönke

Subjects:

500 Science > 540 Chemistry
500 Science > 550 Earth sciences & geology

ISSN:

1086-9379

Publisher:

Meteoritical Society at the University of Arkansas, Dept. of Chemistry and Biochemistry

Language:

English

Submitter:

Sönke Szidat

Date Deposited:

12 Jan 2022 11:47

Last Modified:

12 Jan 2022 11:47

Publisher DOI:

10.1111/maps.13758

BORIS DOI:

10.48350/162247

URI:

https://boris.unibe.ch/id/eprint/162247

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