Ion beam study of a possible extraterrestrial body signature in Libyan desert glass

Ion beams have been employed to get micro-PIXE measurements and ionolumines cence analyses on a natural silica glass, known as Libyan desert glass (LDG ), representing a probable fusion product of desert sandstone due to the im pact of an extraterrestrial body. In particular some brown streaks, which a re present in a few specimens and considered as traces of the impactor, hav e been characterized. The presence of discrete bands with different lumines cence intensity has been revealed by both ionoluminescence and cathodolumin escence. Several hypotheses have been proposed in order to explain the lumi nescence properties of this material. Finally, the usefulness of the synerg ic combination of ionoluminescence and micro-PIXE, to characterize LDG, has been showed. (C) 2000 Elsevier Science B.V. All rights reserved.