Y1

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Y1

Accretionary complex
middle - late Eocene

Sedimentary facies: Marine
Lithofacies (Upper): Sandstone, Mudstone
Lithofacies (Upper, Minor): Conglomerate, Interbedded sandstone and mudstone
Lithofacies (Middle): Mudstone
Lithofacies (Middle, Minor): Sandstone, Conglomerate, Gravel-bearing mudstone, Interbedded sandstone and mudstone
Lithofacies (Lower): Sandstone
Lithofacies (Lower, Minor): Mudstone, Interbedded sandstone and mudstone, Conglomerate
Sedimentary structures: Parallel stratification

Thickness: 150 m or thicker

Yasukawa Formation
[ Upper ]
--------------
Y2
--------------
Y1
/--/--/--/--/-
[ Lower ]

Muro Group (North)
[ Upper ]
/--/--/--/--/-
Kogawa Formation
--------------
Uchikoshi Formation
--------------
Yasukawa Formation
/--/--/--/--/-
[ Lower ]

Muro Group (South)
[ Upper ]
/--/--/--/--/-
Shimotsuyu Formation
--------------
Mitogawa Formation
--------------
Wabuka Formation
/--/--/--/--/-
[ Lower ]

Shimanto Belt (Wakayama pref.)
[ Upper ]
/--/--/--/--/-
Koyasan Group = North Shimanto
/--/--/--/--/-
Hidakagawa Group = North Shimanto
/--/--/--/--/-
Nyunokawa Formation
/--/--/--/--/-
Otonashigawa Group
/--/--/--/--/-
Muro Group
/--/--/--/--/-
[ Lower ]

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

Distribution: Otodani valley - Mount Otosan - Sokoya - Kosamedani valley, Tanabe city, Wakayama pref.; Taiko, Kozagawa city, Higashimuro county, Wakayama pref.

Suzuki et al (1979) Geology of the Kurisugawa District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 54p. (in Japanese with English abstract 5p.)