mountain range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...
in the
Tōhoku region
The , Northeast region, or consists of the northeastern portion of Honshu, the largest island of Japan. This traditional region consists of six prefectures (''ken''): Akita, Aomori, Fukushima, Iwate, Miyagi, and Yamagata.
Tōhoku reta ...
of Honshū, Japan. The range is the longest range in Japan and stretches south from the
Natsudomari Peninsula
is a peninsula on the northern end of the Japanese island, Honshū, that stretches north into Mutsu Bay.
Administratively the area is a part of Aomori Prefecture, and the bulk of the area falls within the jurisdiction of the town of Hiranai, w ...
of
Aomori Prefecture
is a prefecture of Japan in the Tōhoku region. The prefecture's capital, largest city, and namesake is the city of Aomori. Aomori is the northernmost prefecture on Japan's main island, Honshu, and is bordered by the Pacific Ocean to the eas ...
to the Nasu volcanoes at the northern boundary of the Kantō region. Though long, the range is only about wide. The highest point in the range is
Mount Iwate
is a stratovolcano complex in the Ōu Mountains of western Iwate Prefecture, in the Tōhoku region of northern Honshū, Japan. With an elevation of , it is the highest in Iwate Prefecture. It is included as one of the 100 famous mountai ...
, .
The range includes several widely known mountains: Hakkōda Mountains, Mount Iwate,
Mount Zaō
The , commonly called Mount Zaō, are a complex cluster of stratovolcanoes on the border between Yamagata Prefecture and Miyagi Prefecture in Japan. The central volcano of the group includes several lava domes and a tuff cone, Goshiki-dake, which ...
,
Mount Azuma
is an active stratovolcano in Fukushima prefecture, Japan.
It has a conical-shaped crater and as the name "Kofuji" (small Mount Fuji) suggests, the shape of Mount Azuma is like that of Mount Fuji. Mount Azuma's appealing symmetrical crater and ...
Mount Adatara
is a stratovolcano in Fukushima Prefecture, Japan.
It is located about 15 kilometres southwest of the city of Fukushima, Fukushima, Fukushima and east of Mount Bandai. Its last known eruption was in 1996. An eruption in 1900 killed 72 workers a ...
.
Naming
These mountains previously formed the boundary between historical provinces of Mutsu (陸奥国) and Dewa (出羽国). The ''
kanji
are the logographic Chinese characters taken from the Chinese family of scripts, Chinese script and used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese ...
'' for the name of the mountain range was created from one ''
kanji
are the logographic Chinese characters taken from the Chinese family of scripts, Chinese script and used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese ...
'' of the two provinces, 奥 and 羽, respectively.
Geology
The Ōu Mountains began to form in the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Northeastern Japan Arc. This is the result of the Pacific Plate subducting under the
Okhotsk Plate
The Okhotsk Plate is a minor tectonic plate covering the Kamchatka Peninsula, Magadan Oblast, and Sakhalin Island of Russia; Hokkaido, Kantō and Tōhoku regions of Japan; the Sea of Okhotsk, as well as the disputed Kuril Islands. It was ...
. A chain of Quaternary volcanoes along the range forms the volcanic front.