Heavy Metal Concentrations in Futatsudake and Hassaki Pumices of Haruna Volcano

Abstract

This paper describes Cd, Pb, Cu, Ni, Zn, Cr and Mn concentrations in the two well-known pumices (Futatsudake Pumice: FP and Hassaki Pumice: HP) originating from Haruna volcano. Those pumices being the famous Quatenary, Tephras in the Northern Kanto district were collected systematically zone by zone at the outcrops of Mizusawa as FP samples (25)and of Yokomuro as HP samples (10).
The samples were decomposed b y acid digestion and analyzed by atomic absorption spectrometry with diethyldithiocarbamate-isobutyl methyl ketone extraction for Cd, Pb, Cu, Ni and Zn, and directly with no extraction for Cr and Mn.
The average concentrations of these elements in FP and HP samples were 0.56+0.18 ppm for Cd, 24.2±6.3 ppm for Pb, 16.3±7.3 ppm for Cu, 37.7±20.6 ppm for Ni, 81.0±12.6 ppm for Zn, 67.0±17.9 ppm for Cr and 978 ±269 ppm for Mn.
FP was compared with HP in average concentrations and the former showed considerably lower values than HP for Cu, Cr and Mn. The relative values on the average concentrations of FP and HP proved significantly small for Cu, and considerably large for Cd and Zn in comparison with the 35 tephras in the Northern Kanto district. Haruna and Akagi volcanos in contrast to Asama one had smaller relative values for Cu and Ni.