Рассматриваются геологическая история и петрология крупного полигенного вулканического сооружения верхнеплейстоцен-голоценового времени. Этот долгоживущий вулканический центр знаменателен совместным проявлением магм базальтового и трахибазальтового составов, представленных базальт-андезитовой и трахибазальт-трахиандезитовой сериями. Делается вывод о генетической автономности сосуществующих родительских магм, генерированных в разных глубинных источниках области верхней мантии. Разнообразие составов вулканитов обязано многостадийной пространственно-временной кристаллизационной дифференциации магм и смешению последних в промежуточных очагах.

The Ziminy Sopki Volcanic Massif is remarkable for its co-formation from magmas of different potassium alkalinity manifested by three rocks associations (series) with individual evolutional trends: I — andesite-basalts — andesites — dacites; II — andesite-basalts — the intermediate composition andesites; III — high potassium andesite-basalts. Variations of rocks from the revealed series manifest themselves in the above mentioned mineral associations, and the discreteness of rocks regression lines evidence on quite autonomous parental magmas. Orthogonal trends of minerals composition alterations in andesite-basalts with the vector correlating with the potassium alkalinity increase in rocks of associations evidence on existence of the process leading to the enrichment of these magmas with potassium. Thus, we can conclude that, within the single penetrated magmatic system, there are deep intermediate chambers with different conditions for formation of the initial andesite-basalt magmas, which during volcanic activity directly associated with the deeper parental basaltic magma.

The paper describes petrophysical changes of Neogene-Quaternary volcanic rocks from Mutnovsky volcanic region under the action of hydrothermal processes. It was concluded that hydrothermal alterations lead to remarkable changes of physical and mechanical properties of rocks however the tendency of properties variation is different depending from a number of factors. Propylitization causes rocks consolidation, hardening, an increase of elastic properties, a decrease of porosity and disappearing of hygroscopic moisture. The influence of low-temperature fluids on the rocks is not so unequivocally. There can be a decrease as well as an increase of petrophysical properties. The sharp difference by properties, the structure of pore-space and the character and speed of hydrothermal alterations is observed between lavas and volcaniclastic rocks. However the primary differences between these rocks can disappear due to an intensive hydrothermal activity.