Sheveluch Volcano is one of the most productive volcanoes in Kamchatka, characterized during the Holocene by alternating periods of predominantly extrusive and explosive activity. New data on the volumetric parameters of fine ash emissions have been obtained, indicating that the mass of erupted material of dacitic composition during a single moderate-strength eruption can exceed 2 million tons. In those years when gas and ash cloud eruptions were particularly frequent (sometimes more than twenty per month), the total mass of fine dacitic ash can be comparable to the annual discharge of andesitic material (extrusive lavas and tephra), providing a new perspective on the genesis of andesites.

The eruptive history of the Shiveluch andesite volcano included two Holocene events, during which
the volcano erupted unusual rocks: medium-potassium, amphibole-bearing magnesian basalts (7600 years ago)
and high-potassium magnesian basalts with phlogopite and amphibole (3600 years ago). The volumes of tephra
were approximately 0.1 and 0.3 km3, respectively. Some of the mineralogical and geochemical features of the
Holocene basalts were inherited by the subsequent basaltic andesites and andesites. These are similar in Mg
variation ranges of olivine, clinopyroxene, and amphibole phenocrysts, high Mg contents, and high Cr and Ni
concentrations. This and the results of mass-balance calculations do not contradict the view that the Shiveluch
volcanic rocks originated during the crystal fractionation of Holocene basalt melts. However, the other
geochemical features of the Shiveluch rocks, e.g., their similar REE contents, cast doubt on the formation of
the magnesian basaltic andesites through fractional crystallization of magnesian basalt magma and suggest that
they originated as a result of interaction between magnesian basalt magma and a depleted mantle material at a
shallow depth. At the same time, the different mineral compositions of the Holocene medium- and high-potassium
basalts and the results of mass-balance calculations indicate that their parental magmas might be produced
by the melting of different rocks.