くじゅう連山 - Kuju - 10/28/2023

About: Mount Kujū (九重山, Kujū-san), located on the border of Kokonoe and Taketa in Ōita Prefecture, Japan, is a stratovolcano in Kyushu Island, Japan, with a summit elevation of 1,791 metres (5,876 ft). It is one of the 100 Famous Japanese Mountains. It is part of the Aso-Kujū National Park. (Source: Wikipedia)

The Kujū range consists of a dozen or so volcanic bodies gathered in a region of 13km east-west and 10km north-south. The mountains in the range include:

Kujū Mountains

     Mount Kujū (1,787 m) - The main peak (久住山) - Also pictured above

     Mount Nakadake (1,791 m) - The highest peak in Kyushu

     Mount Inahoshi (1,774 m)

     Mount Hōsshō (1,762 m)

     Mount Mimata (1,745 m)

Taisen Mountains

     Mount Taisen (1,786 m)

     Mount North (Kita) Taisen (1,706 m)

     Mount Heiji (1,642 m)

The Kujū volcanic group is mainly composed of andesite and dacite, which is defined as the volcanic activity above the Miyagi pyroclastic flow deposit which formed about 200,000 years ago. The north and south areas of Mt. Kujū are plateau grasslands whose main industry is dairy farming.

Geological Summary: Kujusan is a complex of stratovolcanoes and lava domes lying NE of Aso caldera in north-central Kyushu. The group consists of 16 andesitic lava domes, five andesitic stratovolcanoes, and one basaltic cone. Activity dates back about 150,000 years. Six major andesitic-to-dacitic tephra deposits, many associated with the growth of lava domes, have been recorded during the Holocene. Eruptive activity has migrated systematically eastward during the past 5000 years. The latest magmatic activity occurred about 1600 years ago, when Kurodake lava dome at the E end of the complex was formed. The first reports of historical eruptions were in the 17th and 18th centuries, when phreatic or hydrothermal activity occurred. There are also many hot springs and hydrothermal fields. A fumarole on Hosho lava dome was the site of a sulfur mine for at least 500 years. Two geothermal power plants are in operation at Kuju. (Source: Global Volcanism Program)