Рассмотрены влияние микрогетерогенной структуры магматических расплавов на характер вулканических извержений и процессы преобразования первичных минералов. Исследованы особенности кристаллизации вулканических стекол и их искусственных аналогов. Исходя из определяющей роли степени полимеризации алюмосиликатной составляющей, введен новый структурно-чувствительный параметр (р) , который для всех химических составов магматических пород оказался равным 1+/-0,1. Выявлен физический смысл границы при Р =1+/-0,1, делящей природные расплавы на две группы, отличающиеся по физическим свойствам (электропроводность, вязкость), в частности по поведению при вулканической деятельности (разный характер извержения) и интенсивности взаимодействия первичных кристаллических фаз с расплавом при изменении физико-химических условий в процессе извержения. Проведен сравнительный анализ эволюции минералов в ходе извержения базальтовой (Р=0,7) и андезито-дацитовой (Р=0,95) магм от наиболее закаленных пирокластических продуктов до материала лавовых потоков. Для базальтового извержения сопоставление шлака и лавы дало возможность авторам показать на эволюции хром-пикотитов большую роль обмена кристалл-остаточный расплав и тем самым высокую подвижность элементов в кристаллах при магматических температурах.
Для вулканологов, минералогов

Bezymianny is one of the most active volcanoes in Kamchatka and in the world. In December 2016, activity of the volcano began to intensify after four years of silence during 2012–2016. In 2017, three, and in 2019, two paroxysmal explosive eruptions of the volcano occurred. The work describes the eruption that occurred on March 15, 2019, as well as the events preceding it, based on the study of video and various satellite data. The volcano was monitored using the information system (IS) “Remote monitoring of the activity of Kamchatka and Kurile volcanoes” (VolSatView). The eruption had been predicted by KVERT (Kamchatkan Volcanic Eruption Response Team) staff 6.5 hours before it began. Explosions raised ash up to 15 km above sea level, the eruptive cloud moved northeast and east of the volcano, the main area of the territory where ashfalls were observed was about 210,410 km2 , including 15,000 km2 on land. An animated image of the ash cloud movement from the volcano is shown, made according to a series of images of Himawari-8 in the IS VolSatView (http://kamchatka.volcanoes.smislab.ru/animation/1584509687.gif). After the eruption, aerosol clouds were recorded in the atmosphere at a distance of up to 4000 km in the northeast of the volcano until March 18, 2019. As a result of the eruption, deposits of pyroclastic flows and pyroclastic surges formed on all slopes of the volcano
(mainly on the eastern and southeastern), the area of which reached about 30 km2.

Most of the Kharchinskii and Zarechnyi products, as well as those of the Kharchinskii cinder cones, are magnesian rocks. Mineralogical data suggest that both the basaltic and the andesitic magma were rich in water (≥3-4 and >6-7 wt.%, respectively) and crystallized at high oxygen fugacity (2.0-2.5 orders of magnitude higher than the NNO buffer). These features, coupled with the geochemical characteristics of these basalts and andesites, indicate that they are similar to the rocks of Shiveluch, a volcano also located on the northern flank of the Northern volcanic group, but differ from the rocks of the other volcanoes of this group which are located further south. The Kharchinskii, Zarechnyi, and Shiveluch magnesian basalts differ from the rocks of the Klyuchevskoi volcano and Tolbachik lava field by their higher K, Ba, Sr and lower Ca, Sc, Yb contents at higher La/Yb, Ni/Sc, and La/Ta ratios, while their initial magmas were more hydrous and more oxidized.

This paper presents the results of studying the spatial distribution and structural setting of magnesian basalts and andesites in the Northern group of Kamchatkan volcanoes and in the junction zone of the Kuril-Kamchatka and Aleutian island arcs. The morphology and geologic structure of unique Kamchatkan magnesian basalt stratovolcanoes are described: Kharchinsky, Zarechnyi, and the Kharchinsky regional zone of cinder cones. The reported evidence includes the ages and eruptive histories, and productivities of the volcanoes and the volumes and weights of their edifices. The magnesian basalts were erupted 40-50 thousand years ago, for the first time during the Holocene.