|Holocene Kamchatka volcanoes||
Institute of Volcanology and Seismology
Global Volcanism Program number
53°55' N, 158°05' E, summit elevation 2278 m
Bakening volcano (Figs.1-3) is located in the upper streams of Srednyaya ("Middle") Avacha river. Along with this stratovolcano, Srednyaya and Levaya ("Left") Avacha basins host a suite of monogenetic vents. Immediately to the north of Bakening there is a huge Early Holocene monogenetic silicic lava volcano named Novo-Bakening (Figs. 3-4). To the south of Bakening, a number of Holocene monogenetic cinder cones and maars form a group named Kostakan (Fig. 5). Several large monogenetic cones of Holocene age are also scattered at a distance of 25-30 km east of Bakening: Veer (Fig. 6), Peschany or Zavaritsky, Volcanic Mt. etc). This region is a popular destination for backpacking trips from Petropavlovsk.
Bakening volcano started to form in the late Pleistocene and ceased its activity in the early Holocene (Melekestsev et al., 1999). There have been repetitive collapses of the southeastern sector of the volcano. The oldest took place in the late Pleistocene and created a large collapse crater. After that the volcano was active and produced lava flows, which partly filled the crater. In the early Holocene (8500-8000 14C yrs BP) a new collapse occurred (Melekestev et al., 1999; Ponomareva et al., 2006). The debris avalanche dammed the river to form two beautiful lakes. Further destruction of the cone continued with at least five smaller landslides, producing a sequence of debris avalanche and smaller debris flow deposits along Srednyaya Avacha River and its tributaries. The resulting collapse crater exposes an internal structure of the volcano (Fig. 2). Holocene erupted products are mid-potassic calc-alkaline andesites and dacites (Dorendorf et al., 2000).
Novo-Bakening volcano (Fig. 4) is an Early Holocene monogenetic lava volcano composed of hornblende-bearing mid-potassic dacite (Dorendorf et al., 2000). Its western lava flow is about 5 km long at a maximum width of about 1.5 km. Eastern lava flow is 2-2.5 km long and its frontal part forms a shore of Medvezhie lake (Fig. 3). Total volume of the Novo-Bakening volcanic products is about 1.4-1.6 km3 (Braitseva and Pevzner, 2001).
Holocene cinder cones in Sr. and L.Avacha basins are dominantly basaltic, some of them being notable for high MgO content. The most recent cones (Kostakan, Fig. 5) formed about 600 years BP (Dirksen and Melekestsev, 1999).
Braitseva OA and Pevzner MM (2001) Novo-Bakening volcano of Kamchatka: Its age and tephra stratigraphy. Volcanol Seismol 22 (6): 581-594
Dirksen OV and Melekestsev IV (1999) Chronology, evolution and morphology of plateau basalt eruptive centers in Avacha River area, Kamchatka, Russia. Volcanol Seismol 21 (1): 1-28
Dorendorf F, Churikova T, Koloskov A, Wörner G. (2000) Late Pleistocene to Holocene activity at Bakening volcano and surrounding monogenetic centers (Kamchatka): volcanic geology and geochemical evolution. J Volcanol Geotherm Res 104: 131-151
Melekestsev IV, Dirksen OV, Girina OA (1999) A giant landslide-explosion cirque and a debris avalanche at Bakening volcano, Kamchatka. Volcanol Seismol 20 (3): 265-280
Ponomareva VV, Melekestsev IV and Dirksen OV (2006) Sector collapses and large landslides on Late Pleistocene-Holocene volcanoes in Kamchatka, Russia. J Volcanol Geotherm Res. In press.