Ok4 Tephra

Abbr.: Ok4

Tephra
Pliocene

Lithofacies: Crystalline volcanic ash

Host: Zushi Formation, Hatsuse Formation, Misaki Formation
Thickness: 37 cm

Ok Tephra
[ Upper ]
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Ok4
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Oksco
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Ok3
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Ok2
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Ok1
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[ Lower ]

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

Distribution: Mount Ogusuyama - Kurihama - Abekura - Nagase, Yokosuka city, Kanagawa pref.; Kannonhana seashore - Cape Tenjinnzaki, Sajima, Yokosuka city, Kanagawa pref.

Eto et al. (1998) Geology of the Yokosuka District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 128p. (in Japanese with English abstract 3p.)