Omanago Group (Japan)

Status Unknown Eruption -3050 2341m
Lava dome(s) (Subduction zone / Continental crust (> 25 km))

The Omanago volcano group consists of a series of five closely spaced lava domes that were constructed north and NW of Nantai volcano in Nikko National Park. The highest of the dacitic domes is Omanago, which later erupted andesitic lavas. The Mitsudake dome, which overlooks the hot spring resort of Lake Yunoko, was radiocarbon dated at about 5000 years ago. Mitsudake was constructed on a southerly dipping slope, so that the southern of its two flat-topped domes is lower, and is overlapped by sediments of the Senjogahara plain.

The Omanago volcano group (upper left) consists of a series of five closely spaced lava domes in Nikko National Park. The highest of the dacitic domes is Omanago, located at the SE end of the complex. Mitsu-dake, the NW-most dome, is a complex lava dome. The higher northern peak of the Mitsu-dake complex is out of view to the left, and the lower southern dome forms the low ridge behind the hot spring resort of Yunoko lake in the center of the photo. The prominent peak on the right horizon is Nantai volcano.

Photo by Lee Siebert, 1964 (Smithsonian Institution).

Last updated 2019-08-04 00:28:02