© E. N. Grib1, A. G. Manevich1, O. V. Sobolevskaya1,2

1 Institute of Volcanology and Seismology FED RAS, Petropavlovsk-Kamchatsky, 683006
2 Kamchatka State University, Petropavlovsk-Kamchatsky, 683032
Institute of Volcanology and Seismology, Piip boulevard, 9, Petropavlovsk-Kamchatsky, 683006, Russia
Phone: (41522) 5-94-05, fax: (41522) 5-94-05, e-mail: gen@kscnet.ru

The paper presents mineral phases compositions of the pumice bombs from the Academiya nauk caldera. The results were obtained by means of microprobe study. In our investigation we compare mineral compositions of the pumice bombs with pyroclastic sediments formed in the area of this caldera in quaternary, we define the reasons for K content increase in some pumice bombs. Besides, in this study we estimate thermal profiles in transition (from dike to wall rock) zone for different moments of time and under different initial conditions.