|Age||Between 200,000 and 100,000 years old|
The Caucasus has been affected by volcanic activity during the Late Cenozoic in three areas. One of these is the Kazbek area with the Kazbek, Keli Highland and Dzau systems which were active during the Quaternary.
It contains three volcanoes, Tsru (42°22′52″N 44°01′19″E / 42.381026°N 44.021899°E) also known as Chvriva at 1,500 metres (4,900 ft) altitude, Sazeleti (42°24′16″N 44°00′14″E / 42.404431°N 44.003830°E) at 1,904 metres (6,247 ft) altitude and Bordzhnis or Borgnisi (42°25′46″N 43°58′09″E / 42.429351°N 43.969033°E) at 1,300 metres (4,300 ft) altitude. Sazeleti is a lava cone, the other two volcanoes are fissure vents. Remnants of lava flows have also been found.