Holocene Kamchatka volcanoes
Institute of Volcanology and Seismology
Kamchatka, Russia
Global Volcanism Program number 1000-17
Uzon-Geysernaia caldera







Fig. 10
News on the Valley of Geysers

Uzon-Geysernaia twin calderas form a 9 x 18 km depression (Fig. 1), which originated as a result of large explosive eruptions in the late Pleistocene time. Associated ignimbrite sheet (Fig. 2) covers an area of 1700 km3. A single 14C date on a paleosol, underlying the Uzon-Geysernaia pyroclastic deposits, suggests an age of this eruption of 39 600±1000 BP (Florensky, 1984; Braitseva et al., 1995).

The northwestern part of the caldera (or Uzon caldera) hosts a large geothermal field and numerous hot and cold lakes (Figs. 3 and 4). Present geothermal activity is concentrated in a 0.2-0.3 x 5 km zone filled with boiling springs, gas-steam jets, mudpots, small mud volcanoes, hot lakes and springs with colonies of blue-green algae and thiobacteria (Piip, 1937; Pilipenko, 1976; Karpov, 1992; Leonov et al., 1991). Some of the lakes are located in the craters of phreatic eruptions. The most recent phreatic eruption took place in 1989 and created a 14 m wide crater. The southeastern part of the Uzon-Geysernaia caldera (or Geysernaia caldera) is filled with dominantly late Pleistocene lava domes (Fig. 1). A 4-km-long canyon of the Valley of Geysers (Figs. 1, 5 and 6) is located near the eastern rim of the Geysernaia caldera and hosts nearly 30 geysers, boiling springs, and mudpots. Each of the geysers has its own regime: some erupt strong fountains of steam every few minutes while others "work" once in 0.5-2 hours. The Valley of Geysers was first discovered and described in 1941 by T.I.Ustinova (Ustinova, 1955).

The Uzon caldera hosts a few Holocene volcanic vents. The only definitely Holocene magmatic feature is a tuff ring filled with Dalnee Lake (Fig. 7). The eruption took place 7.6-7.7 ka BP (Braitseva et al., 1995). It produced dark-gray cinder of medium-K tholeiitic andesite composition. Lava dome of Mt. Belaia and its pumice tuff overlie glacial deposits, and are overlain by the Holocene soil-pyroclastic cover, so Mt. Belaia likely formed in the very end of late Pleistocene.

A number of phreatic eruptions took place within the Uzon caldera during the Holocene time. Some of those have been dated: a crater enclosing Khloridnoe Lake formed 1.5-2 ka BP; Bannoe Lake (Figs. 4 and 8) ~3.5 ka BP. Deposits from a phreatic eruption with an age of 7.7 ka BP have been also identified but their source is unknown (Egorova, 1993).

Uzon caldera displays a large variety of thermal waters (Pilipenko, 1976). Boiling waters in the axial part of the thermal field are commonly rich in boron, silicon, and ammonium chloride and have high concentrations of alkali metals (Li, Rb, and Cs) and ore elements (As, Sb and Hg). The rest of the hydrotherms are sulfate-chloride-sodium, hydrocarbonate-sulfate-calcium-sodium and hydrocarbonate ("narzans"). They are produced due to subsurface differentiation and mixing of chloride-sodium and surface waters (Karpov, 1988, 1992; Leonov et al., 1991). Spontaneous gases include CO2, N2, H2, H2S and CH4. These gases contain high concentrations of radon. Oil of methane-naphthene-aromatic type was found in the thermal fields of the Uzon caldera. Extraordinary high optical activity of the oil suggests its biogenic nature (Volcanism..., 1974).

Two types of ore mineralization can be distinguished within the Uzon caldera: sulfurous and mercury-antimony-arsenic. Sulfurous type is represented by relics, lenses and beach deposits of almost monomineral sulphur of a crater-lake genesis contaminated by opal and clay minerals.  Mercury-antimony-arsenic type is represented by realgar-orpiment facies (Leonov et al., 1991).

In spring, non-freezing lakes and rivers of the Uzon caldera are visited by white swans (Figs. 9 and 10).


Braitseva O.A., Melekestsev I.V., Ponomareva V.V., and Sulerzhitsky L.D. (1995) The ages of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region, Russia. Bull Volcanol 57/6: 383-402

Egorova I. A. (1993) Age and paleogeography of the formation of volcano-sedimentary deposits in the Uzon-Geizernaya caldera depression, Kamchatka (according to palynological data). Volcanol Seismol 15/2: 157-177

Florensky I.V. (1984) On the age of Uzon and Krasheninnikov calderas, Volcanol Seismol, 1, 102-105 (In Russian)

Karpov G.A. (1988) Recent hydrothermal springs and Hg-Sb-As mineralization. Moscow, Nauka Publishers, 183 pp (In Russian)

Karpov G.A. (1992) Subsurface hydrothermal genesis of ores and minerals in recent hydrothermal system of Uzon caldera in Kamchatka, Russia. In: Water-Rock Interaction, Kharaka, Y.F. and Maest, A.S., eds., Balkema, Rotterdam, v. 2, p. 1593-1596

Leonov V.L., Grib Ye.N., Karpov G.A., Sugrobov V.M., Sugrobova N.G., and Zubin M.I. (1991) Uzon caldera and Valley of Geysers. In: Active Volcanoes of Kamchatka. Moscow, Nauka Publishers, v. 2: 94-141

Piip B.I. (1937) Thermas of Kamchatka. Trudy SOPS AN SSSR, ser. Kamchatskaya, iss.2, 268 pp. (In Russian)

Pilipenko G.F. (1976) Steam-hydrothermas of Uzon caldera. In: Hydrothermal Systems and Thermal Fields of Kamchatka. Vladivostok, pp.237-266 (In Russian)

Ustinova T.I. (1955) Geysers of Kamchatka. Gosizdat Geographicheskaia Literatura, Moscow, 120 pp. (In Russian)

Volcanism, Hydrothermal Process and Ore Formation (1974) Moscow, Nauka Publishers, 264 pp.