On the fluxes and fates of 3He accreted by the Earth with extraterrestrial particles

One observes appreciable concentrations of 3He in marine sediments. Extensive observational data are available for sediments in the Atlantic and Pacific oceans. We show that besides IDPs, there is an important source which is an important contributor to the flux of 3He in marine sediments. This is the GCR produced 3He in meteoroids of sizes up to ∼1 m. We compare the measured 3He fluxes in marine sediments with those predicted from solar 3He in IDPs, and from GCR produced 3He in secondary fragments of meteoroids of sizes up to ∼1 m, produced during their transit through the atmosphere. Our studies allow us to reach plausible conclusions regarding the predominant source of 3He in marine sediments.