|In the amphitheater of a partially preserved caldera with a diameter of about 2 km, a steep extrusive dome with an explosive crater with a diameter of about 300 m and a depth of 100 m at the top rises to 1017 m above sea level (about 400 m above the bottom of the caldera). The crater crest is very uneven; the southeastern part of it is severely destroyed. On the edge of the ridge there are three characteristic large teeth, on which the volcano was named. The slopes of the agglomerate mantle of the dome are quite flat. On the eastern slope, at an altitude of 700-800 m, there is an explosive crater measuring 150 x 250 m and a depth of 50 m. It is assumed that it was formed after 1915 (Nemoto, 1937). The lavas of the Trezubets volcano belong to two-pyroxene andesite [Горшков, 1967].
Nemoto T. Geologic and petrologic study of the Central Kurile Islands, VI - Dzigoku Volcano, Urup Island // Bulletin of the Volcanological Society of Japan. 1937. V. 3. № 2.
Горшков Г.С. Вулканизм Курильской островной дуги / Отв. ред. Рудич К.Н. 1967. 288 с.