The 410,000 year terrestrial age of eucrite Río Cuarto 001 |
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| Authors: | Jonathan LEVINE Andrés ARAZI Thomas FAESTERMANN Jorge O FERNáNDEZ NIELLO Gunther KORSCHINEK Ana María LA GAMMA Agustín NEGRI Georg RUGEL Peter STEIER Anton WALLNER |
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| Institution: | 1. Chicago Center for Cosmochemistry and Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637, USA;2. Laboratorio TANDAR, Comisión Nacional de Energía Atómica, 1429 Buenos Aires, Argentina;3. Fakult?t für Physik, Technische Universit?t München, 85747 Garching, Germany;4. Unidad de Actividad Química, Comisión Nacional de Energía Atómica, 1429 Buenos Aires, Argentina;5. VERA Laboratory, Faculty of Physics, Universit?t Wien, W?hringer Str. 17, A‐1090 Vienna, Austria |
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| Abstract: | Abstract— We have measured a surprisingly long terrestrial age of 410,000 ±45,0020,000 yr (410 ±2045ka) for basaltic eucrite Río Cuarto 001 using accelerator mass spectrometry of 26Al, 36Cl, and 41Ca. Though many meteorites are known to have survived for tens or hundreds of ka in Antarctica or hot deserts, the mean annual precipitation of 815 mm in Río Cuarto, Cordoba Province, Argentina, makes the long survival of this meteorite remarkable. We propose two explanations for the exceptional preservation of Río Cuarto 001. First, the meteorite contains only trace amounts of metal, so the weathering and oxidation of metallic Fe, which commonly destroys chondrites, is ineffective in this case. Second, the meteorite was found in a relatively young deflation basin, and may have been exhumed only recently from beneath a protective layer of soil. Insofar as the survival on Earth of Río Cuarto 001 is due to environmental factors, there may be other meteorites with comparably long terrestrial ages still to be discovered in the vicinity. |
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