Seppikosan Formation

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Seppikosan Formation Yamamoto et al., 2002

Type locality: Seppikosan-Mineyama forest road, Kamikawa city, Kanzaki county - Yumesaki town, Himeji city, Hyogo prefecture
Volcanic rocks
Large scale caldera-fill deposit
Late Cretaceous
Intruded by: Rhyolite sills, Biotite hornblende quartz diorite dikes, Biotite granite, Orthopyroxene clinopyroxene andesite body

Sedimentary facies (Upper): Lacustrine
Sedimentary facies (Lower): Rhyolite pyroclastic flow deposits
Sedimentary facies (Lower, Minor): Debris avalanche deposits
Lithofacies (Upper): Conglomerate, Sandstone, Interbedded sandstone and siltstone
Lithofacies (Lower): Lapilli tuff
Lithofacies (Lower, Minor): Breccia

Thickness: ca. 700 m
Thickness (Sills): ca. 300 m
Upper limit: Unconformity (Kurooyama Formation)
Lower limit: Unconformity (Maizuru Belt, Yamasaki Formation)

(Invalid name) Ikuno Group (Yamasaki, Hyogo pref.)
[ Upper ]
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Mineyama Formation
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Nagusayama Formation
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Fukadanigawa Formation
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Kurooyama Formation
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Okawachi Formation
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Seppikosan Formation
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[ Lower ]

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

Distribution: Mount Seppikosan, Yumesaki town, Himeji city, Hyogo pref.; Mount Chozuisan, Shiso city, Hyogo pref.; Sakanotsujitoge pass, Kamikawa city, Kanzaki county, Hyogo pref.

Yamamoto et al. (2002) Geology of the Yamasaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 48p. (in Japanese with English abstract 4p.)