Kronotsky volcano looking northeast, from the outer slopes of Krasheninnikov pre-caldera edifice. A huge edifice of the volcano is dissected by deep gullies (barrancos). Most of the volcano was formed in Late Pleistocene. However, there are several Holocene cinder cones on its slopes and the last weak phreatic eruption was reported to have occurred in 1922-23, with still later fumarolic activity.
The two cones of the Holocene edifice are embraced by Old Kikhpinych (Mt.Peak) mid-Pleistocene eroded volcano. Older Zapadnyi ("Western") cone is closer to us, younger Savich cone is the highest one. A large cinder cone named Duga ("Arc") is at the foreground. The cone and its several 5-10 km long lava flows formed about 3200 14C years BP. It is composed of tholeitic basaltic andesite very similar to that of Krasheninnikov volcano.
Late Pleistocene-Holocene cinder cones of the southern part of Tolmachev Dol ("Plateau") looking southwest. Opala volcano is at the background. Baranii Amphitheater crater, filled with extrusive domes, is at the left, just over the rim of the plateau.
Bolshoi ("Big") Semiachik is a group of Late Pleistocene-Holocene stratovolcanoes and extrusive domes located within a large caldera. Here we see the massif from the western rim of the caldera (Bort ridge). Bolshoi Semiachik (or Zubchatyi) volcano per se is the large Late Pleistocene edifice at the background. Several Holocene extrusive domes and thermal fields are located west and southwest from the volcano.
Gamchen volcanic massif, comprising three Late Pleistocene and one Holocene cones, looking northwest. Reddish Holocene cone is named Baranii ("Sheep's"). It started to form about 3600 14C years BP as evidenced by stratigraphic position of its cinders immediately below AV1 marker ash (3500 14C years BP) from Avachinsky volcano. The cone has been formed in several spurts of activity during an interval of 3600-3000 14C years BP. Kizimen volcano is seen at the background left of the Gamchen summit.