Answer:
The oceanic lithosphere consists of about 50 km of crust and 100 km or more of the uppermost mantle. It consists mainly of mafic crust and ultramafic mantle and is denser than the continental lithosphere, for which the mantle is associated with a crust made of felsic rocks. The continental lithosphere is thicker than its oceanic lithosphere and does not subduct. Its crust is also richer in radioactive elements. Moreover, heat flow beneath continents is significantly lower than under oceans, which tends to show that continents are more insulating.
Explanation:
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