sustain (sustains 3rd person present) (sustaining present participle) (sustained past tense & past participle) 1 verb If you sustain something, you continue it or maintain it for a period of time. But he has sustained his fierce social conscience from young adulthood through old age... V n. ...a period of sustained economic growth throughout 1995.
If oceanic and continental crust collides the denser one which is the oceanic crust will be subducted, go underneath, the continental crust. The high heat of the mantle causes the oceanic crust to melt into magma. If the crust gets cracked this allows magma to rise and come out of the crust as lava which will form Volcanoes. When two continental crusts collide, the crust is forced to go upwards which forms mountains.
The slow decay of radioactive particles such as uranium, thorium and potassium produces heat deep within the earthâs core.The heat is transferred or conducted to surrounding rocks (called the mantle) causing a proportion of these to melt and become magma.Convection within the mantle enables magma to move upwards to the earthâs surface.he heat is transferred or conducted to surrounding rocks (called the mantle) causing a proportion of these to melt and become magma. Convection within the mantle enables magma to move upwards to the earthâs surface.