Hirobatake Formation

Type locality: Hirobtake, Ayabe city - Narahara, Oe town, Fukuchiyama city, Kyoto prefecture
Coherent formation
early - middle Triassic, Olenekian
Contemporaneous heterotopic facies: Narahara Formation

Sedimentary facies: Marine
Lithofacies (Upper): Shale
Lithofacies (Upper, Minor): Sandstone
Lithofacies (Lower): Sandstone
Lithofacies (Lower, Minor): Shale

Thickness: 420 m or thicker

Yakuno Group (Kawahigashi, Kyoto pref.)
[ Upper ]
/--/--/--/--/-
Narahara Formation
/--/--/--/--/-
Hirobatake Formation
/--/--/--/--/-
[ Lower ]

Central zone (Kyoto - Hyogo)
[ Upper ]
/--/--/--/--/-
Nabae Group
?--?--?--?--?-
Yakuno Group
~~~~~~~~~~~~~~
Maizuru Group
/--/--/--/--/-
[ Lower ]

Maizuru Belt
[ North ]
/--/--/--/--/-
North zone
/--/--/--/--/-
Central zone
/--/--/--/--/-
South zone
/--/--/--/--/-
[ South ]

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

Distribution: Hirobtake, Ayabe city, Kyoto pref.; Narahara, Oe town, Fukuchiyama city, Kyoto pref.
Fossils (Upper): Michelinoceras sp.
Fossils (Lower): Ammonoids, Retzia sp., Isocrinus (Stem)
Fossils (Upper, Shellfishes): Nuculana nogamii, Sisenna? japonica
Fossils (Lower, Shellfishes): Bakevellia okuyamensis, Claraia okuyamensis, Neoschizodus cf. laevigatus, Neoschizodus shikii, Palaeoneilo cf. ellipltica, Pecten cf. ussuricus, Selenimyalina? sp.
Fossils (Lower, Brachiopods): Lingula cf. borealis, Sisena? japonica, Spiriferina sp.

Igi and Kuroda (1965) Oeyama, Explanatory Text of the Geological Map of Japan, Scale 1:50,000, Geological Survey of Japan, 81p. (in Japanese with English abstract 12p.)