The paper presents data on specified northern boundary of the Holocene volcanic activity in Kamchatka. This boundary is located 80 km to the north for the frontal volcanic zone and 180 km to the northwest from Sheveluch Volcano for the zone of the Sredinny Range. For the first time numerous evidence for the Holocene volcanic activity within the Kamchatkan zones with no deep seismicity and located to the north from the Aleutian transform fault were detected, studied and dated using geologic methods and isotope geochemistry. Radiocarbon age for the eruptions was estimated.

Numerous Holocene volcanic centres (5 stratovolcanoes, including 4 active and potentially dangerous, and 12 monogenetic centres) are discovered within Sredinny Range of Kamchatka. Their exact ages are determined. Spatial and temporal characteristics, as well as composition of Holocene volcanic rocks witness against direct connection of magma genesis with contemporary Pacific plate subduction. Sub-meridional chronological trends and elements of grouping, identified for Holocene volcanic activity of Sredinny Range of Kamchatka, may indicate seismo-geodynamical nature of young volcanic activity and associated with it advection in the extinct island arc system.

Изучены два вулканических центра в пределах Срединного хребта Камчатки - Южный и Северный Черттук. Рассмотрены морфология и строение шлаковых конусов и лавовых потоков, особенности состава их пород. Подсчитаны объемы изверженного материала для обоих центров (>2 км3 каждый). Впервые получены С-датировки (-3550 л.н.) для Южного Черпука и приведены данные о предполагаемом возрасте (-1740 г. н.э.) Северного Черпука. Обсуждается проблема генезиса указанных вулканических центров.

Tephrochronological and radiocarbon investigations of soil-pyroclastic depositsalong the line Shiveluch Volcano - Chernyi Yar - Bering I. have detected and identified the ashes oflargest (for the past 6500 years) eruptions on Shiveluch Volcano in the southeastern sector of the ashabundance area, as well as the ashes of Bezymyannyi, Ksudach, Klyuchevskoi, Avacha and Khangarvolcanoes. A detailed radiocarbon dating of peat deposits in Chernyi Yar has not only improved the agedeterminations of the eruptions themselves but also helped in the determination of ash fall rate for thelower Kamchatka R. valley, namely, once in 191 years. Apart from the 1964 tephra, we suggest for useas regional geochronological markers the ash horizons of Shiveluch Volcano having the followingrounded radiocarbon dates: 265 (SH1), 965 (SH2), 1450, 2800, 3600 (SP), 4105 (SHDV), 4800, as well asthe ashes from Ksudach 1806 (KS1) and Avacha 5489 (AV2) volcanoes.

For the first time ever among the Russian papers, this article presents description of material composition of rocks from submarine Minami-Hiyoshi Volcano, which is a part the Hiyoshi Volcanic Complex located in the northern area of the Mariana Island Arc. The investigation provided new data on structure, chemical and mineral composition of rock composing it, as well as genesis of the Minami-Hiyoshi lavas. The investigation revealed genetic affinity of all studied rocks and showed that they originate from one basaltic magma, while structural and petrographic differences are caused by various processes of differentiation and dynamics of melt on its way to the surface.

A lineament analysis of the relief was made using a detailed bathymetry map of the region drawn according to the results of multi-beam echo-sounding. The authors separated linear objects of the relief, measured their course azimuths, plotted the rose diagram of the lineament directivities of the region, and built the models of the surface and subsurface deformation field of the region at separating the blocks of dominant stress and strain. The blocks travel along the lines of alternation of stress sign (block borders). The directivities
of the block borders were compared with the lineaments directivities resulting in conclusion that they both have spatial and generic relations. The systems of linear forms directivities of the relief and the borders of surface and subsurface blocks partially correspond to the four main systems of the global disjunctive network (planetary fracturing), which suggests a considerable influence of the latter on the structural plan of the region.Redistribution of stresses is associated with the modern geological processes leading to the formation of new
configurations of seabed relief and partial destruction of the old surfaces of guyots.