Nemrut (volcano) of the earliest trade routes. Two eruptions of Nemrut were probably witnessed by people of Urartu, an ancient state located in the eastern Turkey. These eruptions occurred c. 787 BC (period of King Menua) and c. 657 BC (period of King Rusa II), and the latter eruption might cause the sudden disappearance of the city Uaiais located 30 km east of Süphan. In the 1980s, Japanese volcanologists studied the evolution of gases inside the caldera of Nemrut. They found that the ratio of helium isotopes He/He is 1.06, which indicates volcanic activity (most of the measured helium evolved from the
Nemrut (volcano) as pyroclastic emissions and slag. Eruption of different periods were either effused or explosive. Nemrut is located on a fault that crosses the volcano from the north to the south and contains the main crater and a number of small craters, maars, hot springs and fumaroles. The volcanic activity of Nemrut occurred in three stages: the formation of a cone (pre-caldera stage), the post-caldera stage, and the late stage. Further, divisions are debatable and are based on different interpretations of the stratigraphic data. The formation of Nemrut and the first stage of eruptions began about 1 million years ago with