ark h ok h ▁vol cano ▁and ▁several ▁la va ▁dom es ▁( Er man i , ▁F id ark ok h ▁and ▁others ). ▁ ▁N . I . ▁Sk h irt lad ze ▁first ▁studied ▁the ▁vol cano es ▁and ▁divided ▁the ▁vol can ism ▁into ▁gla cial ▁and ▁post g la cial ▁stages . ▁Later ▁research ▁indicated ▁three ▁phases ▁of ▁vol can ism : ▁A ▁first ▁phase ▁ 2 4 5 – 1 7 0 ka ▁involved ▁la va ▁d ome ▁formation ▁including ▁K ord ier it ovy i ▁d ome , ▁Pat ara - N ep isk alo ▁vol cano ▁and ▁Kab ard z hin – S ak ok he ▁centre ▁and ▁its ▁associated ▁a ▁la val ▁flow ▁in ▁the ▁Arag vi ▁valley . ▁A ▁second ▁phase ▁ 1 3 7 – 7 0 ka ▁with ▁large ▁scale ▁eff us ive ▁activity ▁included ▁the ▁" Py ram idal ▁Pe ak " ▁Vol cano ▁which ▁dam med ▁local ▁rivers ▁with ▁la va ▁flows . ▁From ▁ 9 0 ka ▁on ▁activity ▁formed ▁Did i - N ep isk alo ▁and ▁the ▁Ek is om ▁and ▁K hor is ar ▁dom es . ▁The ▁third ▁phase ▁less ▁than ▁ 3 0 ka ▁with ▁evidence ▁that ▁it ▁continued ▁into ▁the ▁Hol oc ene ▁formed ▁Eastern ▁K hor isa ▁and ▁Pl os k aya ▁Vers h ina . ▁Activity ▁of ▁East ▁K hor is ar ▁Vol cano ▁sp ans ▁both ▁stages ▁and ▁created ▁la va ▁flows ▁in ▁the ▁T erek ▁river ▁valley ,