Kuni qoqqodama tectonic plate adunya kana agarsisa. Tectonic plateiin kuta planeta kenya kana crust fi gubba mantle dha (kuni laman walii galatti lithosphere jedhamu. Plate kuni furdina hanga 100km (60 miles) kan qabu yoo ta'u, waan gossa lama ofii kessa qaba: tokko, oceanic crust (akkasumas sima kan jedhamu) kan silicon fi magnesium ofii kessa qabu fi continental crust (sial kan jedhamu) kan silicon fi almunium ofii kessa qabu dha. Qabenyii gossa crust laman gargari jirra, Oceanic crust (crustiin bishaan jalla) bayyinan cabbi (dhaka) basalt (""mafic"") kan ofii kessa qabu yoo ta'u, continental crust (crust lafa jalla) immo cabbi (dhaka) granite (""felsic"") kan walit-qabama (density) diqa qaban ofii kessa qaba.