Towa Granodiorite

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Towa Granodiorite Okamura, 1957

Plutonic rocks
Late Cretaceus (95.5, 76.8 Ma, Rb-Sr)
Intruded by: Hashirajima Granite
Intruded in: Kuga Group, Gamano Granodiorite

Lithofacies: Hornblende biotite granodiorite, Biotite granodiorite
Lithofacies (Minor): Biotite hornblende tonalite
Structures (Minor): Foliated

Upper limit: Abut unconformity (Takahama Group)

Younger Ryoke Granitoids (Suooshima island, Yamaguchi pref.)
[ Young ]
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Towa Granodiorite
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[ Old ]

Ryoke Belt
[ Young ]
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Ryoke Metamorphic Rocks
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Younger Ryoke Granitoids
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Older Ryoke Granitoids
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[ Old ]

------ Transitional, ~~~~~~ Intrusive, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

Distribution: Hashirajima island - Hashima island - Teshima island - Hodakajima island, Iwakuni city, Yamaguchi pref.; Towa - Tachibana - Nasakejima island - Ukajima island, Suooshima city, Oshima county, Yamaguchi pref.

Matsuura (1997) Geology of the Kurahashi Jima and Hashira Jima District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 53p. (in Japanese with English abstract 4p.)