TRACE-ELEMENT CONCENTRATION AND DISTRIBUTION IN IVORY

The trace element content and distribution in ivory from elephants and hippopotami were measured for both natural elements and elements present due to pollution. The National Accelerator Centre Nuclear Microprobe was used to investigate trace elements heavier than Ca, and distributions of these trace elements were measured over small areas (ca. 1 mm(2)), using the Dynamic Analysis imaging method in the GeoPIXE software package. Quantitativity of elemental maps was checked by complementary point analyses in the same area as where the elemental maps were taken from and found to be accurate to within around 10%. The possibility of locating ivory on the basis of the trace element concentrations, determined by the environment in which these animals live, was demonstrated by using correspondence analysis.