Shiroyama Lavas

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Shiroyama Lavas Oikawa and Ishizuka, 2011

Invalid synonym: Tenshozan Basalt

Type locality: Mount Tenshozan - Mount Shiroyama, Yugawara city, Ashigarashimo county, Kanagawa prefecture
Volcanic rocks
Middle Pleistocene (ca. 0.4 - 0.3 Ma, K-Ar)
Intruded by: Dykes

Sedimentary facies: Terrestrial
Lithofacies (Upper): Orthopyroxene clinopyroxene andesite lava
Lithofacies (Upper, Minor): Pyroclastic breccia, Tuff breccia, Hornblende dacite
Lithofacies (Lower): Orthopyroxene clinopyroxene basaltic andesite - andesite lava
Lithofacies (Lower, Minor): Pyroclastic breccia, Tuff breccia, Hornblende rhyolite

Thickness: 10 m or thicker
Upper limit: Unconformity (Shiroyama Lavas)

Yugawara volcano
[ Upper ]
+__+__+__+__+_
Shiroyama Lavas
~~~~~~~~~~~~~~
Fudotaki Lavas
~~~~~~~~~~~~~~
[ Lower ]

Hakone volcanoes
[ Upper ]
+__+__+__+__+_
Hakone volcano
~~~~~~~~~~~~~~
Yugawara volcano
~~~~~~~~~~~~~~
[ Lower ]

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

Distribution: Shinzakigawa river - Mount Tenshozan - Mount Shiroyama, Yugawara city, Ashigarashimo county, Kanagawa pref.; Mount Izusan - Izumi, Atami city, Shizuoka pref.; Kuwahara, Kannami city, Tagata county, Shizuoka pref.

Oikawa and Ishizuka (2011) Geology of the Atami District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 61p. (in Japanese with English abstract 3p.)