Elemental composition studied by electron microprobe. (a)
Energy-dispersive x-ray analysis (EDXA) spectrum recorded in a region with low
levels of Zn. The halogens Br and I are present in considerable quantities;
there is also some Cl. (b) EDXA spectrum from a region rich in Zn.
With increasing Zn concentration, the Cl concentration considerably increases,
whereas the Br and I concentrations tend to decrease. (c) Local Cl
concentration plotted against local Zn concentration. The occurrence of the
two elements is highly correlated, and the data appear to lie on a straight
line. •, Data from the jaw tip; ○, data from the middle part of the
jaw, containing less Zn.