Radioactive halos as possible indicators for geochemical processes

Geochemical Journal, Vol. 10, pp. 185 to 195, 1976
185
Radioactive halos as possible indicators for
geochemical processes in magmatites
H. MEIER and W. HECKER
Staatliches Forschungsinstitut für Geochemie, Bamberg, Federal Republic of Germany
(Received August 9, 1976)
In systematic microscopic measurements completed by fission track studies the occurrence of
polonium halos and polonium bands could be confirmed in biotites of different areas. The abundance of
the different types of polonium halos is given by the order 210Po ) 218Po ) 214Po. As magmatic and often
also hydrothermal mechanisms are contrary to geological evidences a supergene hypothesis has been
supposed for the genesis of the polonium halos. According to this mechanism polonium isotopes are
accumulated out of uranium- or radium-bearing solutions which are liberated from rocks by leaching
processes of percolating weathering waters. The concept of the given origin of polonium halos may be
significant in discussing problems of dating, uranium prospection and the origin of secondary uranium
deposits.