alt ▁that ▁er u pts ▁under ▁open ▁air ▁( that ▁is , ▁sub a er ial ly ) ▁forms ▁three ▁distinct ▁types ▁of ▁la va ▁or ▁vol can ic ▁depos its : ▁sc oria ; ▁ash ▁or ▁c inder ▁( bre cc ia ); ▁and ▁la va ▁flows . ▁ ▁Bas alt ▁in ▁the ▁to ps ▁of ▁sub a er ial ▁la va ▁flows ▁and ▁c inder ▁con es ▁will ▁often ▁be ▁highly ▁ves ic ulated , ▁im part ing ▁a ▁light weight ▁" f ro thy " ▁texture ▁to ▁the ▁rock . ▁Bas alt ic ▁c ind ers ▁are ▁often ▁red , ▁col oured ▁by ▁ox id ized ▁iron ▁from ▁weather ed ▁iron - rich ▁min er als ▁such ▁as ▁py ro x ene . ▁▁ ʻ A ʻ ā ▁types ▁of ▁block y , ▁c inder ▁and ▁bre cc ia ▁flows ▁of ▁thick , ▁vis c ous ▁bas alt ic ▁la va ▁are ▁common ▁in ▁Hawai ʻ i . ▁P ā ho e ho e ▁is ▁a ▁highly ▁fluid , ▁hot ▁form ▁of ▁bas alt ▁which ▁tends ▁to ▁form ▁thin ▁apr ons ▁of ▁mol ten ▁la va ▁which ▁fill ▁up ▁h ollow s ▁and ▁sometimes ▁forms ▁la va ▁la kes . ▁L ava ▁tub es ▁are ▁common ▁features ▁of ▁p ā ho e ho e ▁er u ptions . ▁ ▁Bas alt ic ▁t uff ▁or ▁py ro cl astic ▁rocks ▁are ▁rare ▁but ▁not ▁unknown . ▁Usually ▁bas alt ▁is ▁too ▁hot ▁and ▁fluid ▁to ▁build ▁up ▁sufficient ▁pressure ▁to