alis , ▁and ▁Sit on ▁Und ae , ▁by ▁cat ast roph ic ▁flo ods ▁origin ating ▁from ▁Ch ry se ▁Plan it ia , ▁Vall es ▁Mar iner is , ▁Ju vent ae ▁Ch asma , ▁and ▁the ▁southern ▁Ac id alia ▁region ▁of ▁Mars . ▁ ▁The ▁d unes ▁of ▁Sit on ▁Und ae ▁contain ▁am orph ous ▁sil ica - co ated ▁glass - rich ▁sand . ▁The ▁lack ▁of ▁evidence ▁for ▁the ▁presence ▁of ▁vol cano es ▁in ▁the ▁region ▁of ▁Plan um ▁B ore um , ▁as ▁well ▁as ▁the ▁absence ▁of ▁evidence ▁of ▁any ▁large - scale ▁m elt ▁depos its ▁due ▁to ▁cr ater ▁impact , ▁suggests ▁that ▁these ▁sil ica - co ated ▁depos its ▁may ▁have ▁formed ▁by ▁alter ation ▁of ▁the ▁bas alt ic ▁s ands ▁through ▁acid ic ▁action . ▁Further , ▁it ▁is ▁the or ised ▁that ▁acid ic ▁alter ation ▁of ▁glass y ▁depos its ▁may ▁have ▁been ▁a ▁common ▁conversion ▁mechanism ▁on ▁Mars , ▁especially ▁at ▁high ▁lat itudes . ▁ ▁Im ages ▁from ▁THE M IS ▁ ▁See ▁also ▁▁ ▁H ag al ▁d une ▁field ▁▁ ▁N ili ▁P ater a ▁d une ▁field ▁ ▁O gy g is ▁Und ae ▁ ▁References ▁▁ ▁Category : D unes ▁on ▁Mars ▁Category : M are ▁B ore um ▁quad rangle <0x0A> </s> ▁In to ▁the ▁Blood stream ▁is ▁the ▁sixth ▁studio ▁album ▁by ▁Australian ▁singer ▁song writer ▁Arch ie ▁Ro ach . ▁The ▁album ▁was ▁released ▁in ▁