T. Ossaka et al., MAJOR-ELEMENT ANALYSIS OF SELECTED ROCK AND VOLCANIC ASH SAMPLES IN THE UNZEN AREA, JAPAN, BY X-RAY-FLUORESCENCE SPECTROSCOPY, Journal of radioanalytical and nuclear chemistry, 183(2), 1994, pp. 235-244
Determination of major elements in natural solid samples by X-ray fluo
rescence spectroscopy (XRF) with a fusion disc technique is described.
Data obtained by the present XRF analytical system were found to have
satisfactorily high reliability. Five rock samples and a volcanic ash
sample with varying ages ranging from the present to 180 000 years, d
erived by the current and past volcanic activities in the Unzen area,
Nagasaki, Japan were analyzed for their major elements' compositions u
sing the above mentioned system. The chemical composition of the magma
under this area has changed very little at least over the last 180 00
0 years.