Cadmium, Lead, Copper, Nickel and Zinc Concentrations in the Quaternary Tephras in the Northern Kanto District

Abstract

This paper describes. Cd, Pb, Cu, Ni and Zn concentrations in the noted Quaternary Tephras in the Northern Kanto District. Thirty-five samples (including nine ones collected. from different zones at Minasawa) were well-known pumice-fall or pumice-flow deposits originated from Asama, Akagi, Haruna and Nantai volcano (Table 1). These were taken from some localities in Gunma (10 localities), Nagano (3 locs. ) and Tochigi Prefecture (4 locs. ). The samples were decomposed by acid digestion and analyzed by diethyldithiocarbamateisobutyl methyl ketone extraction-atomic absorption spectrometry.
Data show considerable concentration ranges of 0.28 to 0.77 ppm for Cd, 9.3 to 51.1 ppm for Pb, 2.0 to 60.8 ppm for Cu, 8.1 to 103 ppm for Ni and 17.3 to 124 ppm for Zn. The average concentrations of thirty-five samples were O.46 ppm for Cd, 22.8 ppm for Pb, 22.2 ppm for Cu, 41.2 ppm for Ni and 67.4 ppm for Znthe samples had some correlation between eiements. The Kanuma pumices from Akagi had noticeable low Cu, Ni and Zn concentrations as compared with another one from Akagi volcano and those from other volcanoes.