Unit III

[ Top ] [ Japanese ]

Unit III

Volcanic rocks
Holocene

Lithofacies: Clinopyroxene-bearing orthopyroxene hornblende dacite, Clinopyroxene orthopyroxene hornblende andesite
Lithofacies: Pyroclastic surge deposit, Pyroclastic fall deposit
Lithofacies: Pumiceous lapilli, Volcanic ash
Sedimentary structures (Unit III): Parallel stratification, Sandwave stratification, Slump structures

Mode of eruption: Phreatomagmatic
Eruptive volume: ca. 0.09 km³ DRE
Thickness (Unit III): ca. 2 m
Thickness (Unit III, A unit): 2 mm - 15 cm

Numazawako Pyroclastic Deposit
[ Upper ]
--------------
Unit IV
--------------
Unit III
--------------
Unit II
--------------
Unit I = Numazawa-Numazawako Pyroclastic Flow Deposit
--------------
[ Lower ]

Numazawa volcano
[ Upper ]
--------------
Numazawako Pyroclastic Deposit / Numazawako Lahar Deposit
--------------
Numagozen Pyroclastic Deposit
--------------
Maeyama Lava
--------------
Sozan Lava
--------------
Mizunuma Pyroclastic Deposit
--------------
Mukurezawa Lava
--------------
Shirifukitoge Pyroclastic Deposit / Nm-SB Tephra
~~~~~~~~~~~~~~
[ Lower ]

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

Distribution: Lake Numazawa - Tadami river, Aizu basin, Fukushima pref.

Masubuchi and Ishizaki (2011) Jour. Geol. Soc. Japan, vol.117, no.6, pp.357-376 DOI
Yamamoto et al. (2006) Geology of the Kitakata District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 63p. (in Japanese with English abstract 5p.)
Yamamoto and Komazawa (2004) Geology of the Miyashita District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, AIST, 71p. (in Japanese with English abstract 5p.)