Fumaroles on active dangerous stratovolcano near Tohya lake in southwestern Hokkaido.
A new parasitic cone, Showa-shinzan, erupted dacite lava from the southeast flank of Usu-zan in 1944-1945, emitting very high-temperature steam (over 800° C) consisting of water vapor, hydrogen, HF, HCl and boric acid. Fumarole gases here have the highest concentration of tin vapour (7 ppm) of any volcano (Giggenbach & Matsuo, 1991).

It has erupted four times since 1900: in 1910 (which created Meiji-shinzan, 1944–45 (which created Shōwa-shinzan), August 7, 1977, and on March 31, 2000. To the north lies Lake Tōya. Mount Usu formed on the southern rim of the caldera containing the lake.
The volcano is a major tourist attraction.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List

19 valid minerals.

Detailed Mineral List:

ⓘ Alunite

Formula: KAl₃(SO₄)₂(OH)₆

References:

Africano, F, Bernard, A (2000) Acid alteration in the fumarolic environment of Usu volcano, Hokkaido, Japan. Journal of Volcanology and Geothermal Research, 97 (1) 475-495 doi:10.1016/s0377-0273(99)00162-6

ⓘ Anhydrite

Formula: CaSO₄

References:

ⓘ Baryte

Formula: BaSO₄

References:

ⓘ Bismuthinite

Formula: Bi₂S₃

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Cristobalite

Formula: SiO₂

References:

ⓘ Galeite

Formula: Na₁₅(SO₄)₅F₄Cl

References:

Oskarsson (1981), Jour. Volcanology & Geothermal Research: 10: 93-111.

ⓘ Galena

Formula: PbS

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Greenockite

Formula: CdS

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Gypsum

Formula: CaSO₄ · 2H₂O

References:

ⓘ Halite

Formula: NaCl

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Hematite

Formula: Fe₂O₃

References:

ⓘ Hydrokenoralstonite

Formula: Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O

References:

ⓘ 'Hypersthene'

Formula: (Mg,Fe)SiO₃

ⓘ Native Tellurium

Formula: Te

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Pickeringite

Formula: MgAl₂(SO₄)₄ · 22H₂O

References:

Matsubara, S. et al (2002) Sublimates of Usu Volcano, Hokkaido, Japan (2002 annual meeting of Japanese Association of Mineralogists, Petrologists and Economic Geologists)

ⓘ Powellite

Formula: Ca(MoO₄)

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Pyrite

Formula: FeS₂

References:

Bernard, A. (1985), Thèse de doctorat, University Libre de Bruxelles

ⓘ Quartz

Formula: SiO₂

References:

ⓘ Rheniite

Formula: ReS₂

References:

Bernard & Dumortier (1986): Proceedings 11th International Conference Electron Microscopy, 1691-1692

ⓘ 'Silica'

References:

ⓘ Tamarugite

Formula: NaAl(SO₄)₂ · 6H₂O

References:

Matsubara, S. et al (2002) Sublimates of Usu Volcano, Hokkaido, Japan (2002 annual meeting of Japanese Association of Mineralogists, Petrologists and Economic Geologists)

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Native Tellurium	1.CC.10	Te
Group 2 - Sulphides and Sulfosalts
ⓘ	Greenockite	2.CB.45	CdS
ⓘ	Galena	2.CD.10	PbS
ⓘ	Bismuthinite	2.DB.05	Bi₂S₃
ⓘ	Pyrite	2.EB.05a	FeS₂
ⓘ	Rheniite	2.EB.35	ReS₂
Group 3 - Halides
ⓘ	Halite	3.AA.20	NaCl
ⓘ	Hydrokenoralstonite	3.CF.05	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
Group 4 - Oxides and Hydroxides
ⓘ	Hematite	4.CB.05	Fe₂O₃
ⓘ	Quartz	4.DA.05	SiO₂
ⓘ	Cristobalite	4.DA.15	SiO₂
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘ	Anhydrite	7.AD.30	CaSO₄
ⓘ	Baryte	7.AD.35	BaSO₄
ⓘ	Alunite	7.BC.10	KAl₃(SO₄)₂(OH)₆
ⓘ	Galeite	7.BD.10	Na₁₅(SO₄)₅F₄Cl
ⓘ	Pickeringite	7.CB.85	MgAl₂(SO₄)₄ · 22H₂O
ⓘ	Tamarugite	7.CC.10	NaAl(SO₄)₂ · 6H₂O
ⓘ	Gypsum	7.CD.40	CaSO₄ · 2H₂O
ⓘ	Powellite	7.GA.05	Ca(MoO₄)
Unclassified
ⓘ	'Hypersthene'	-	(Mg,Fe)SiO₃
ⓘ	'Silica'	-

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Alunite	KAl₃(SO₄)₂(OH)₆
H	ⓘ Gypsum	CaSO₄ · 2H₂O
H	ⓘ Pickeringite	MgAl₂(SO₄)₄ · 22H₂O
H	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
H	ⓘ Tamarugite	NaAl(SO₄)₂ · 6H₂O
O	Oxygen
O	ⓘ Alunite	KAl₃(SO₄)₂(OH)₆
O	ⓘ Anhydrite	CaSO₄
O	ⓘ Baryte	BaSO₄
O	ⓘ Cristobalite	SiO₂
O	ⓘ Galeite	Na₁₅(SO₄)₅F₄Cl
O	ⓘ Gypsum	CaSO₄ · 2H₂O
O	ⓘ Hematite	Fe₂O₃
O	ⓘ Hypersthene	(Mg,Fe)SiO₃
O	ⓘ Pickeringite	MgAl₂(SO₄)₄ · 22H₂O
O	ⓘ Powellite	Ca(MoO₄)
O	ⓘ Quartz	SiO₂
O	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
O	ⓘ Tamarugite	NaAl(SO₄)₂ · 6H₂O
F	Fluorine
F	ⓘ Galeite	Na₁₅(SO₄)₅F₄Cl
F	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
Na	Sodium
Na	ⓘ Galeite	Na₁₅(SO₄)₅F₄Cl
Na	ⓘ Halite	NaCl
Na	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
Na	ⓘ Tamarugite	NaAl(SO₄)₂ · 6H₂O
Mg	Magnesium
Mg	ⓘ Hypersthene	(Mg,Fe)SiO₃
Mg	ⓘ Pickeringite	MgAl₂(SO₄)₄ · 22H₂O
Mg	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
Al	Aluminium
Al	ⓘ Alunite	KAl₃(SO₄)₂(OH)₆
Al	ⓘ Pickeringite	MgAl₂(SO₄)₄ · 22H₂O
Al	ⓘ Hydrokenoralstonite	Na_0.5(Al,Mg)₂(F,OH)₆ · H₂O
Al	ⓘ Tamarugite	NaAl(SO₄)₂ · 6H₂O
Si	Silicon
Si	ⓘ Cristobalite	SiO₂
Si	ⓘ Hypersthene	(Mg,Fe)SiO₃
Si	ⓘ Quartz	SiO₂
S	Sulfur
S	ⓘ Alunite	KAl₃(SO₄)₂(OH)₆
S	ⓘ Anhydrite	CaSO₄
S	ⓘ Baryte	BaSO₄
S	ⓘ Bismuthinite	Bi₂S₃
S	ⓘ Galeite	Na₁₅(SO₄)₅F₄Cl
S	ⓘ Galena	PbS
S	ⓘ Greenockite	CdS
S	ⓘ Gypsum	CaSO₄ · 2H₂O
S	ⓘ Pickeringite	MgAl₂(SO₄)₄ · 22H₂O
S	ⓘ Pyrite	FeS₂
S	ⓘ Tamarugite	NaAl(SO₄)₂ · 6H₂O
S	ⓘ Rheniite	ReS₂
Cl	Chlorine
Cl	ⓘ Galeite	Na₁₅(SO₄)₅F₄Cl
Cl	ⓘ Halite	NaCl
K	Potassium
K	ⓘ Alunite	KAl₃(SO₄)₂(OH)₆
Ca	Calcium
Ca	ⓘ Anhydrite	CaSO₄
Ca	ⓘ Gypsum	CaSO₄ · 2H₂O
Ca	ⓘ Powellite	Ca(MoO₄)
Fe	Iron
Fe	ⓘ Hematite	Fe₂O₃
Fe	ⓘ Hypersthene	(Mg,Fe)SiO₃
Fe	ⓘ Pyrite	FeS₂
Mo	Molybdenum
Mo	ⓘ Powellite	Ca(MoO₄)
Cd	Cadmium
Cd	ⓘ Greenockite	CdS
Te	Tellurium
Te	ⓘ Native Tellurium	Te
Ba	Barium
Ba	ⓘ Baryte	BaSO₄
Re	Rhenium
Re	ⓘ Rheniite	ReS₂
Pb	Lead
Pb	ⓘ Galena	PbS
Bi	Bismuth
Bi	ⓘ Bismuthinite	Bi₂S₃

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Mount_Usu

Other Regions, Features and Areas containing this locality

AsiaContinent

Eurasian Plate

North Japan ArcVolcanic Arc

Okhotsk PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Katsui, Y., Oba, Y., Onuma, K., Suzuki, T., Kondo, Y., Watanabe, T., Niida, K., Uda, T., Hagiwara, S., Nagao, T., Nishikawa, J., Yamamoto, M., Ykeda, Y., Katagawa, H., Tsuchiya, N., Shirahase, M., Nemoto, S., Yokoyama, S., Soya, T., Fujita, T., Inaba, K., Koide, K. (1978a) Preliminary report of the ruption of the Usu volcano. Journal of the Facultyof Science, Hokkaido University, series IV: 18(3): 385-408.

Niida, K., Katsui, Y., Suzuki, T., Kondo, Y. (1980) The 1977-1978 erption of Usu volcano. Journal of the Faculty of Science, Hokkaido University: 19(3): 357-394.

Matsuo, S., Ossaka, J., Hirabayashi, J., Ozawa, T., and Kimishima, K. (1982) Chemical nature of volcanic gases of Usu volcano in Japan. Bulletin Volcanology: 45(3): 261-264.

Oba, Y., Katsui, Y., Kurasawa, H., Ikeda, Y., and Uda, T. (1983) Petrology of historic rhyolite and dacite from Usu volcano, North Japan. Journal of the Faculty of Science, Hokkaido University, series IV: 20: 275-290.

Fujimaki, Hirokazu (1986) Fractional crystallization of the basaltic suite of Usu volcano, southwest Hokkaido, Japan, and its relationships with the associated felsic suite. Lithos, 19 (2) 129-140 doi:10.1016/0024-4937(86)90004-6

Bernard, A. and Symonds, R.B. (1988) The specification of trace metals in high temperature gases from Usu volcano Japan. EOS, Transactions of the American Geophysical Unon: 69: 514.

Giggenbach, W.F., Matsuo, S. (1991) Evaluation of results from Second and Third IAVCEI Field Workshops on Volcanic Gases, Mt Usu, Japan, and White Island, New Zealand. Applied Geochemistry, 6 (2) 125-141 doi:10.1016/0883-2927(91)90024-j

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