Question

Choose the correct description of the conveyor-like action of plate tectonics on Earth

A - Earth's mantle is broken up into plates that float beneath the overlying lithosphere. The bottoms of the mantle's convection cells drag the tops of the plates, making them move. This movement causes spreading in some places and subduction in others.
B - Earth's lithosphere is broken up into plates that float beneath the overlying mantle. The bottoms of the mantle's convection cells drag the tops of the plates, making them move. This movement causes spreading in some places and subduction in others.
C - Earth's lithosphere is broken up into plates that float on the underlying mantle. The tops of the mantle's convection cells drag the bottoms of the plates, making them move. This movement causes spreading in some places and subduction in others.
D - Earth's mantle is broken up into plates that float on the underlying lithosphere. The tops of the mantle's convection cells drag the bottoms of the plates, making them move. This movement causes spreading in some places and subduction in others.

Answer 1

The correct description of plate tectonics is that Earth's lithosphere, consisting of the crust and upper mantle, floats on the underlying mantle and is moved by convection cells, causing spreading and subduction zones. So the correct option is C.

Step-by-step explanation:

The description of the conveyor-like action of plate tectonics on Earth that is correct is: that Earth's lithosphere is broken up into plates that float on the underlying mantle. The tops of the mantle's convection cells drag the bottoms of the plates, making them move. This movement causes spreading in some places and subduction in others. Hence, the correct answer is C - Earth's lithosphere is broken up into plates that float on the underlying mantle. The tops of the mantle's convection cells drag the bottoms of the plates, making them move. This movement causes spreading in some places and subduction in others.

Tectonic plates are composed of Earth's crust and the uppermost, rigid portion of the mantle, together called the lithosphere. They move at a rate of millimeters to a few centimeters per year due to the slow convection of the mantle. At divergent boundaries, plates are moving away from each other, causing the formation of new crusts and ridges like those in the Atlantic Ocean. At convergent boundaries, one plate can be forced beneath another in a subduction zone, which is often associated with ocean trenches and volcanic activity, such as that off the western coast of South America.

Answer 2

Option C

Step-by-step explanation:

• The procedure includes tectonic plates being hauled into the mantle at specific focuses and moving ceaselessly from one another at others, in what has been named 'the transport line'.

• Plate tectonics relies upon the reverse connection between thickness of rocks and temperature.

• At mid-maritime edges, rocks are hot and their thickness is low, making them light or progressively ready to glide. As they move away from those edges they chill off and their thickness increments until, where they become denser than the hidden hot mantle, they sink and are 'hauled' under.