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The Flux of Meteorites to the Earth: Determinations by Terrestrial Techniques |
NSF Arizona Accelerator Mass Spectrometry Facility, The University of Arizona, 1118 East Fourth Street, Tucson, AZ 85721, USA
The results of 14C measurements of 95 meteorites from the Allan Hills region in Antarctica are reported, and terrestrial residence ages calculated. This includes meteorites from the different icefields at Allan Hills and the adjacent Elephant Moraine meteorite stranding area. We determined that terrestrial ages of these Antarctic meteorites can range from recent falls to >40 ka, which is the practical limit for these 14C measurements. The terrestrial age determinations on meteorites from these sites can vary dramatically; the differences between the ages observed from these sites and some of the factors influencing them are discussed. Weathering products found on these meteorites show 14C ages younger than the terrestrial age of the meteorites studied. Calculation of infall rates based on meteorites recovered and their age distributions suggests a minimum infall rate of 40–60 meteorites (>10 g) per 106 km2 per year, in reasonable agreement with the infall rates estimated by Hallidays group based on meteoroid fluxes.