Fig. 8: The XRF spectra collected from the blue areas.

a XRF spectrum collected from points of B1, B8, E2, E5, F2, G3 and (b) XRF spectrum collected from points of A6, A10.
a XRF spectrum collected from points of B1, B8, E2, E5, F2, G3 and (b) XRF spectrum collected from points of A6, A10.