В сообщении приведено краткое описание химического состава и петрографии первых порций экструзивных лав и пирокластического материала, изверженных в апреле – начале мая и в августе 2024 г. в пределах нового эруптивного центра им. 300-летия РАН на западном склоне вулканического массива Шивелуч.

В сообщении приведены первые краткие данные о составе пород палеовулкана г. Шиш в хребте Кумроч. Показано, что по содержаниям главных элементов, хрома, никеля, а также по степени обогащения легкими PЗЭ и обеднения тяжелыми РЗЭ и иттрием породы г. Шиш близки к магнезиальным андезитам северного фланга Центрально-Камчатской депрессии.

The 2020–2022 field works gave results that were used as a basis for describing the geological structure and whole-rock compositions for Kronotsky Volcano, one of the least known eruption centers in the East Volcanic Belt (EVB), Kamchatka. The stratovolcano edifice was estimated to be 350 km3 in volume, which is much above the respective figures for the other stratovolcanoes in the EVB frontal zone. The rocks are low-K and high-Fe tholeiitic basalts and basaltic andesites (SiO2 = 47.04‒53.15 wt %; K2O = 0.24‒0.65 wt %; FeO*/MgO = 1.2‒2.89). The basalts have extremely low concentrations of silica, potassium, titanium, and phosphorus compared with the rocks of the other frontal volcanoes in Kamchatka. The petrochemical differences thus identified were used to more accurately classify structures situated at the junction between the nearby Kronotsky and Krasheninnikov volcanoes. The acquired data will make the basis for further petrologic and geo-
chemical characterization of the volcano, as well as being possibly used for reconstructing the sequence of volcanic events in the area of study, including a more accurate history of the formation of Lake Kronotsky.

In July-August 2023, field work was carried out on the northern slopes of Kronotsky volcano in the territory of the Kronotsky State Reserve, which is rarely visited by researchers. The aim of our work was to sample lavasthat build the volcanic edifice in this sector, and also to search for traces of the volcano’s explosive activity in the Holocene. This report lists and illustrates interesting findings and the main results of the work. In particular, lava flows, dikes and pyroclastic horizons were sampled at altitudes ranging from 780 to 2200 m; several cinder and lava cones were discovered; samples of cognate inclusions and xenoliths were found. Inaddition, Holocene soil-pyroclastic sections, presumably containing tephra horizons from Kronotsky volcano, were documented in detail and sampled.