Volcanism and geochemistry of soil and vegetation cover of Kamchatka. Communication 1. Geochemical features of volcanic surface ashes

Common geochemical features of volcanic near-surface ashes of Kamchatka (ashes located under the surface organogenic soil horizons) are their depletion by most chemical elements in comparison with average indicators for volcanic rocks of corresponding composition and relative enrichment of a limited range of elements, mainly typomorphic for main rocks (P, Mg V, Cr, Cu, Zn, Zr, Sb). Against the background of small variations in the contents of chemical elements in the ashes of different areas of the peninsula, the range of their priority elements is determined by their petrochemical composition. The active activity of the Northern group of volcanoes of Kamchatka causes a relatively high content of mobile forms of elements in the near-surface ashes of the Northern province in comparison with the ashes of the southern part of the peninsula.