Implantation in Interplanetary Dust of Rare-Gas Ions from Solar Flares

Science  26 Aug 1966:
Vol. 153, Issue 3739, pp. 981-984
DOI: 10.1126/science.153.3739.981


Measurements of excess Ar36 + Ar38 ( released mainly at 1200°C) in magnetic concentrates of Pacific sediments and in a dense concentrate of Greenland dust agree within an order of magnitude with expected concentrations implanted by solar-flare ion streams of energy less than 10 Mev per atomic-mass unit. The agreement implies that more than 10 percent of each concentrate may be extraterrestrial, depending on size distribution and flare spectra. Rare-gas measurements on fine-grained dust can provide data on: solar-flare "paleo-ion" fluxes, energy spectra, and isotopic abundances; identification, mineralogy, and chemistry of interplanetary dust; influx rates to Earth and sedimentation rates of oceanic cores; and lunar-surface residence and mixing times.