Toyonishi Group

Toyonishi Group
Stratigraphic range: Tithonian to Lower Hauterivian
TypeGroup
Sub-unitsKiyosue Formation, Yoshimo Formation
UnderliesToyora Group
OverliesKanmon Group
Thickness300–900 metres (980–2,950 ft)
Lithology
PrimaryMudstone, Sandstone
OtherSiltstone, conglomerate, limestone
Location
RegionShimonoseki City, Yamaguchi
CountryJapan
Type section
Named forToyonishi-son (Village)
Named byMatsumoto, 1949

The Toyonishi Group is a group of Mesozoic rock strata in Japan, and was originally named by Tatsuro Matsumoto in 1949. It distributes in the southern half of Shimonoseki City, Yamaguchi Prefecture, southwest Japan, and deposited during the Uppermost Jurassic-Lower Cretaceous along the East Asian continental margin.