Determination of trace elements in meteorites

Abstract

For some years, the meteorites, being aggregations of extra-terrestrial matter, have stimulated world-wide interest. This is connected with continuously expanding space research, especially because, until now, no space probes have transferred any interplanetary or interstellar matter to Earth, except minute amounts of micrometeorites. Furthermore, the determination of certain radionuclides produced by cosmic rays in meteorites allows derivation of their “ages”, i.e. of the time since their impact on Earth, or of the time, respectively, during which they have been exposed to cosmic rays.Much interest is caused by the trace elements, especially because from their contents conclusions can be drawn concerning the cosmic abundance of the rarer elements. Many elements of the periodic system, being trace constituents in meteorites, are determinable by neutron activation analysis.In Vienna a research project has been developed by some academic institutions, concerning the determination of main, minor, and trace constituents of the various types of meteorites, using modern separation and determination methods.We have begun to investigate an iron meteorite from Magura (Czechoslovakia) and a hypersthene-olivine chondrite from Mocs (Rumania). The iron meteorite was investigated by gamma-spectrometry and the stone meteorite by gamma-spectrometry as well as spectrochemically.The preliminary results are the following: Magura iron: Main and minor constituents: Fe, Ni (6, 35%), Co (0, 80%), C (0, 38%)Trace constituents: Mn, Cr, Cu, Ga, V, Ag, Sb, Sn, Hf, Ir, Au; not yet made sure: Sm, Eu, Tb, Dy, Ho, Cp, Re, Os, Ru Mocs chondrite: Main constituents Si (38, 2%), Mg, Fe, CaMinor and trace constituents: Ni, Al, Na, Mn, Cr, Ga, Sc, Sb, Cu, Co, Ti, V, Au, Tr, not yet made sure: Sm, Dy, Ho, Yb, Cp, Re.