On-Yn Tephra

[ Top ] [ Japanese ]

On-Yn Tephra

Abbr.: On-Yn, Yn-1

Invalid synonym: Ub, S-2 (Kisodani valley, Lower)

Tephra
Pleistocene

Lithofacies: Volcanic ash, Pumice

Source: Ichinoike volcano
Lower limit: Unconformity (Kisogawa Mudflow Deposit)

Marishiten volcano group (Yonger Ontake Tephra Group)
[ Upper ]
~~~~~~~~~~~~~~
On-Sk
~~~~~~~~~~~~~~
On-Ki
~~~~~~~~~~~~~~
On-Yn
~~~~~~~~~~~~~~
On-Og
~~~~~~~~~~~~~~
On-Ss
~~~~~~~~~~~~~~
On-Ys
~~~~~~~~~~~~~~
On-Mt
~~~~~~~~~~~~~~
On-Sn
~~~~~~~~~~~~~~
On-Kn
~~~~~~~~~~~~~~
On-Kr
~~~~~~~~~~~~~~
[ Lower ]

Younger Ontake Volcanic Rocks
[ Upper ]
~~~~~~~~~~~~~~
Marishiten volcano group
~~~~~~~~~~~~~~
Takigoshi Formation
~~~~~~~~~~~~~~
Mamahahadake volcano group
~~~~~~~~~~~~~~
[ Lower ]

Ontake volcano
[ Upper ]
~~~~~~~~~~~~~~
Younger Ontake Volcanic Rocks
~~~~~~~~~~~~~~
Older Ontake Volcanic Rocks
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Nagano pref.

Yamada and Kobayashi (1988) Geology of the Ontakesan District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 136p. (in Japanese with English abstract 9p.)