The paper provides data characterizing the volcanic activity in the Kurile Islands in 2017. The authors studied eruptions of Ebeko Volcano (Paramushir Island), Chirinkotan (Chirinkotan Island) and intensification of activity of Sarychev Peak (Matua Island) and Kudryavy (Iturup Island) volcanoes.

Обсуждается активизация сейсмичности под Удинскими вулканами, свидетельствующая о возможном возобновлении их вулканической активности. Значимость активизации проанализирована по методике статистической оценки уровня сейсмичности СОУС’09, применяющейся для мониторинга сейсмичности Камчатки.

В конце 2016 г. начался очередной эпизод эруптивной активности вулкана Безымянный на Камчатке. Рассматриваются предвестниковые ситуации, выявленные по возрастанию уровня сейсмичности и проанализированные в реальном времени перед тремя извержениями вулкана в ноябре 2016 г. – марте 2017 г.
Применение формализованной методики вероятностного прогноза, разработанной для вулкана Безымянный В.А. Салтыковым по сейсмическим данным 1999–2014 гг., позволило сформулировать вероятностные прогнозы извержений в режиме реального времени, которые были переданы Камчатскому филиалу Российского экспертного совета по прогнозу землетрясений, оценке сейсмической опасности и риска (КФ РЭС) и признаны оправдавшимися.

Development history and character of activity of the active volcanoes of south-Kamchatka group Mutnovsky and Gorely volcanoes which are the closest to the city of Petropavlovsk-Kamchatsky are described. They are popular objects of cognitive and sporting tourism. Geological map, schemes and descriptions of the excursion routes are given. They let us to acquaint with the brightest manifestations of volcanism, structure formation and gas-hydrothermal activity connected with it, with a nature of Mutnovsko-Gorelovsky region.
Edition is directed to the wide range of readers who has an interest in volcanic geology and nature of Kamchatka students of local lore, naturalists and tourists.

This is the final article that describes various for petro- and oreogenesis consequences of the contamination of nickel-bearing magma with siliceous material (quartzites), which led to the replacement of ultrabasic ore-hosting rocks (cortlandites) with ultramafic (amphibole orthopyroxenites). Besides, the paper describes the products of metamagmatic variations of pyroxene ore cumulates in biotite-amphibole rocks inported by water-potassium fluid. The author shows the unconventional results of fluid influence on similar cumulates with relics of quartzite xenoliths accompanied by the formation of ore granophyric autobreccies, as well as ore-bearing derivatives from the process of magma mixing (auto-contamination). We introduce an intraformational classification of copper-nickel ores by their associations with host rocks of different composition and origin — from juvenile magmatic ultrabasites, contaminated and ultramafites and melanodiorites to hybrid granitoids. The dynamics of the formation of intrusive ore-magmatic systems and the plausible reason of differences in the ore content of large and small intrusions are discussed.

The article presents a discussion of contaminants in nickeliferous magmas of various composition and phase as metamorphic rocks and fluids. It describes distribution of different solid-phase contaminants (xenoliths) in intrusions and compositionally different accumulative rocks. Xenogenic material is represented both by host rocks with intrusions and deeper rocks with no surface outcropping. In order to estimate contamination effect on the variety of accumulative rock series and location of sulphide ores as a benchmark standard we use similar data on a ore-bearing intrusive rocks formed by nearly non-contaminated high-magnesian (parental) magma. Besides, the article describes contamination of magma by high-alumina coal slates as well as variety of forming series of its cumulative rocks and exotic floatation graphite-sulphide ores in aluminous granodiorites in one of the intrusive bodies.

On March 24, 2017 Kambalniy Volcano started to erupt after a 500-year-long period of rest. The eruption continued till April 10, 2017. The paper provides the analysis of atmospheric wave disturbances as wavetrains of quasi-sinusoidal oscillations with a frequency of 8 Hz ("acoustic tremor" or AT), which occurred at certain moments during the eruption. Besides, the paper describes 3 strongest seismic signals registered at the initial stages of the eruptions simultaneously with AT, which was registered using an infrasound station IS44 installed 208 km NW far from the volcano. The nearest "Pauzhetka" seismic station installed 19 far from the volcano allowed monitoring the seismic build-up, which was short (2 days) and weak (Кmax = 8.6). Lack of definite discrete infrasound signals, which are usually caused by non-stationary process during explosive eruptions, gives evidence for peculiar pattern of formation and effusion of ash-and-gas emissions. Such uncommon acoustic radiations and seismic build-up prove the presumption that this eruption should be classified as a hydrothermal event.

Numerous summit and parasitic eruptions of moderate potassium magnesian and high-alumina basalts and basaltic andesites, their mineralogic and geochemical features, and the composition of in situ chilled melt inclusions in the olivine of cinder lapilli discharged by Klyuchevskoi Volcano all provide evidence of the presence of magma chambers beneath the volcano. This is also supported by a dualism in the variation of CaO and A1203 concentrations in olivine and clinopyroxene during crystallization. The mineralogic features in the high-alumina basalts that were discharged by all parasitic eruptions of Klyuchevskoi provide evidence of magnesian magma being emplaced from a deeper chamber into a shallow high-alumina chamber. The distribution of incoherent elements in the volcano's magnesian and aluminiferous rocks shows that they came from a single mantle source. The geochemical and mineralogic data are in good agreement with the results of geophysical surveys that concern the structure and properties of the lithosphere beneath Klyuchevskoi.