Hosoya Sand Member

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Hosoya Sand Member (Kuroda, 1958)

Invalid synonym: Kamihosoya Sand

Type locality: Hosoya town, Toyohashi city, Aichi prefecture
Coherent formation
middle Pleistocene

Sedimentary facies: Marine
Sedimentary facies (Top): Backshore
Sedimentary facies (Upper): Foreshore
Sedimentary facies (Middle): Shoreface
Sedimentary facies (Lower): Offshore
Lithofacies: Sands
Lithofacies (Minor): Gravels
Sedimentary structures: Parallel stratification Wave ripples, Trough cross-stratification, Swaley cross-stratification

Thickness: 20 - 30 m
Upper limit: Conformity (Arai Mud Member), Unconformity (Toshima Sand and Gravel Member, Kanbe Gravel Member)
Lower limit: Transitional (Nanane Sandy Mud Member)

Futagawa Formation
[ Upper ]
~~~~~~~~~~~~~~
Arai Mud Member
--------------
Hosoya Sand Member
--------------
Nanane Sandy Mud Member
?--?--?--?--?-
[ Lower ]

Atsumi Group
[ Upper ]
~~~~~~~~~~~~~~
Gumihara Formation
~~~~~~~~~~~~~~
Toyohashi Formation
~~~~~~~~~~~~~~
Tahara Formation
~~~~~~~~~~~~~~
Futagawa Formation
?--?--?--?--?-
[ Lower ]

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

Distribution: Hosoya town - Nishinanane town - Shiroshita town - Kojima town, Toyohashi city, Aichi pref.; Nishihamada - Gumihara, Mutsure town, Tahara city, Aichi pref.; west coast of Lake Hamana - Shirasuka, Kosai city, Shizuoka pref.
Fossils (Plants): Fagus crenata, Zanthoxylum sp.
Fossils (Trace fossils): Macaronichnus segregatis
Tephra: At-1

Nakashima et al. (2008) Geology of the Toyohashi and Tahara District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 113p. (in Japanese with English abstract 3p.)
Nakashima et al. (2008) Jour. Geol. Soc. Japan, vol.114, no.2, pp.70-79 DOI