Abstract
“Okama” is a crater lake at Mt. Goshiki-dake (1, 674m), which is a central cone in the Uma-no-se caldera, at the top of Mt. Zao, Miyagi Prefecture.
There is a shallow depression in contact with the east side of the Okama crater. A disturbance of the alternation of volcanic ash and sand is seen on the eastern wall of its crater as is shown in the sketch.
Thus it is confirmed that the depression is an older crater.