Which layer of the Earth is thicker under continents?

Answer 1

The crust under the ocean is thinner than continental crust. Ocean crust is also, on average, richer in minerals containing iron and magnesium, giving it a greater density than continental crust. Imagine placing two slabs of wood next to each other in a swimming pool. The first slab will be thin piece of oak and the second will be thicker piece of pine. The pine, being less dense than the oak, will stick up higher in the water and at the same time will also ride lower in the water than the oak. Similarly, both ocean crust and continental crust float on the mantle (more specifically the asthenosphere which is a layer in the upper mantle). Ocean crust is like the oak and continental crust is like the pine. Ocean crust is composed largely of the igneous rocks basalt, gabbro, and peridotite. Continental crust is much more diverse in its composition, but on average is similar in density to granite.

Answer 2

Ocean-floor crust: Basalt. Dense, iron rich, lower silica

Continental crust: Granite. Less dense, little or no iron, higher silica.

There is no crust under the continents - apart from subducted sea-floor fragments here and there.

Answer 3

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Answer 4

Earth's crust is far thicker under the continents.

Answer 5

The continental crust is thickest beneath mountains.

Answer 6

The Oceans.

Answer 7

The crust.