am orphism ▁within ▁the ▁bel t . ▁ ▁Met am orph osed ▁bas al ts ▁are ▁important ▁hosts ▁for ▁a ▁variety ▁of ▁hydro ther mal ▁ore ▁depos its , ▁including ▁gold ▁depos its , ▁co pper ▁depos its , ▁vol can ogen ic ▁massive ▁sul f ide ▁ore ▁depos its ▁and ▁others . ▁ ▁We ather ing ▁▁ ▁Comp ared ▁to ▁other ▁rocks ▁found ▁on ▁Earth ' s ▁surface , ▁bas al ts ▁weather ▁relatively ▁fast . ▁The ▁typically ▁iron - rich ▁min er als ▁ox id ise ▁rapidly ▁in ▁water ▁and ▁air , ▁st aining ▁the ▁rock ▁a ▁brown ▁to ▁red ▁colour ▁due ▁to ▁iron ▁ox ide ▁( rust ). ▁Chem ical ▁weather ing ▁also ▁releases ▁readily ▁water - sol ub le ▁c ations ▁such ▁as ▁calci um , ▁sod ium ▁and ▁mag nes ium , ▁which ▁give ▁bas alt ic ▁areas ▁a ▁strong ▁buffer ▁capacity ▁against ▁acid ification . ▁Cal ci um ▁released ▁by ▁bas al ts ▁bind s ▁up ▁CO 2 ▁from ▁the ▁atmosphere ▁forming ▁Ca CO 3 ▁acting ▁thus ▁as ▁a ▁CO 2 ▁trap . ▁To ▁this ▁it ▁must ▁be ▁added ▁that ▁the ▁er u ption ▁of ▁bas alt ▁itself ▁is ▁often ▁associated ▁with ▁the ▁release ▁of ▁large ▁quantities ▁of ▁CO 2 ▁into ▁the ▁atmosphere ▁from ▁vol can ic ▁g ases . ▁ ▁Us es ▁▁ ▁Bas alt ▁is ▁used ▁in ▁construction ▁( e . g . ▁as ▁building ▁blocks ▁or ▁in ▁the ▁ground work ), ▁making ▁c ob bl est ones ▁( from ▁column ar ▁bas alt )