Are ocean floors and continental masses in upper mantle layer?

Continents are on the crust of the earth. The crust itself is made of continents and ocean floors. The mantle lies below this. The upper mantle is called the asthenosphere. The continents are made of silica and aluminium (sial) and ocean floors of silica and magnesium (sima). read more

The upper mantle is called the asthenosphere. The continents are made of silica and aluminium (sial) and ocean floors of silica and magnesium (sima). The sial and sima together with the asthenosphere make up the lithosphere. read more

hypothesis, introduced by Alfred Wegener and others early in the 1900s, of the breakup of a parent continent, Pangaea, starting near the close of the Mesozoic era, and resulting in the present arrangement of continental shields and intervening ocean-basin floors. read more