▁cr ust , ▁and ▁ar id ▁conditions ▁since ▁the ▁Mi oc ene ▁have ▁preserved ▁its ▁structures . ▁Its ▁vol cano es ▁are ▁arranged ▁in ▁north - s outh ▁and ▁north western ▁align ments , ▁which ▁may ▁indicate ▁a ▁ru pt ure ▁of ▁the ▁cr ust ▁above ▁shall ow ▁mag ma ▁res er voir s . ▁ ▁A uc an qu il cha ▁under w ent ▁a ▁north west ward ▁fl ank ▁collapse , ▁generating ▁a ▁de br is ▁a val anche ▁depos it . ▁The ▁de br is ▁a val anche ▁desc ended ▁ ▁and ▁ran ▁for ▁ ▁with ▁an ▁az im uth ▁of ▁ 2 1 1 ° , ▁eventually ▁covering ▁an ▁area ▁of ▁. ▁The ▁flow ▁was ▁ch anne led ▁between ▁Mi ño ▁Vol cano ▁and ▁Cer ro ▁C um bre ▁Neg ra ▁( an ▁er oded ▁la va ▁mass if ) ▁towards ▁the ▁dry ▁Rio ▁Lo a ▁valley , ▁favour ing ▁the ▁pres ervation ▁of ▁the ▁slide ▁depos it . ▁The ▁proxim al ▁parts ▁of ▁the ▁slide ▁are ▁covered ▁by ▁younger ▁er upt ive ▁products ▁and ▁also ▁by ▁mor aines , ▁indicating ▁that ▁the ▁slide ▁was ▁followed ▁by ▁at ▁least ▁one ▁gla cial ▁episode . ▁The ▁slide ▁la cks ▁the ▁hum mock y ▁top ography ▁usually ▁found ▁on ▁de br is ▁a val an ches ▁but ▁has ▁radial ▁rid ges ▁and ▁gro ov es . ▁Another ▁lands lide ▁occurred ▁during ▁the ▁Red ondo ▁stage ▁on ▁the ▁eastern ▁side ▁of ▁the ▁main ▁vol cano ▁into ▁the ▁Sal ar ▁de ▁Car c