information:filtering, structural:expansion
Geology

The Caucasus is formed by the northward collision of the Arabian Plate against the Eurasian Plate that causes numerous earthquakes in the region. The fault zone is complex and the large lateral displacement at the level of Anatolia and Iran prevents the creation of a subduction phenomenon and explains the rarity of volcanoes in the mountain range.

Elbrus started to form there 10 million years ago. The ejecta from the volcano covers an area of 260 km. Fragments of rhyolite and rhyodacite as well as tuff and ignimbrite formations have been found and have been allowed by uranium-lead dating to situate the formation of the main caldera around −700,000 years, probably corresponding to the end of a major eruptive cycle. Geochronological dating has revealed subsequent synchronous eruptive cycles in different focimagmatic deposits of the Greater Caucasus, demonstrating the common geological origin of this volcanic activity. It happens that modest fumaroles still sometimes escape from the eastern flank of Elbrus, at the level of the ancient lava flow of 24 kilometers long oriented from the crater to the north-northeast, and hot springs originate on the slopes of the mountain.