▁with ▁Boliv ia ▁and ▁within ▁the ▁Al to ▁Lo a ▁National ▁Reserve . ▁Part ▁of ▁the ▁Central ▁Vol can ic ▁Zone ▁of ▁the ▁And es , ▁the ▁strat ov ol cano ▁has ▁the ▁form ▁of ▁a ▁r idge ▁with ▁a ▁maximum ▁height ▁of ▁. ▁The ▁vol cano ▁is ▁embedded ▁in ▁a ▁larger ▁cluster ▁of ▁vol cano es ▁known ▁as ▁the ▁A uc an qu il cha ▁cluster . ▁This ▁cluster ▁of ▁vol cano es ▁was ▁formed ▁in ▁stages ▁over ▁eleven ▁million ▁years ▁of ▁activity ▁with ▁varying ▁mag ma ▁output , ▁including ▁la va ▁dom es ▁and ▁la va ▁flows . ▁A uc an qu il cha ▁vol cano ▁proper ▁is ▁formed ▁from ▁four ▁units ▁that ▁er upt ed ▁between ▁ 1 . 0 4 – 0 . 2 3 ▁million ▁years ▁ago . ▁During ▁the ▁ice ▁ages , ▁both ▁the ▁principal ▁A uc an qu il cha ▁complex ▁and ▁the ▁other ▁vol cano es ▁of ▁the ▁cluster ▁were ▁subject ▁to ▁gla ci ation , ▁resulting ▁in ▁the ▁formation ▁of ▁mor aines ▁and ▁cir ques . ▁ ▁The ▁cluster ▁has ▁generated ▁la va ▁r anging ▁in ▁composition ▁from ▁and es ite ▁to ▁d ac ite , ▁with ▁the ▁main ▁vol cano ▁being ▁exclus ively ▁of ▁d ac it ic ▁composition . ▁System atic ▁variations ▁in ▁temperature , ▁cry stal ▁and ▁bi ot ite ▁content ▁have ▁been ▁recorded ▁during ▁the ▁evolution ▁of ▁the ▁cluster . ▁ ▁At ▁A uc an qu il cha ▁vol cano ▁there ▁is ▁some ▁f umar ol ic ▁activity , ▁and