Seafloor Spreading Concepts

The thin, solid, outermost layer of Earth; is either continental (landmasses) or oceanic (ocean floors).

The boundary between two tectonic plates moving away from each other; if on land, it creates rift valleys; if on the sea floor, it creates new ocean crust and mountainous ridges.

Melted or molten rock material beneath Earth's surface; cools slowly to form rocks with larger crystals.

<p>An underwater mountain system formed by plate tectonics; the largest single volcanic feature on Earth.</p> Signup and view all the answers

<p>The formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges.</p> Signup and view all the answers

<p>The process in which a denser plate is pushed downward beneath a less dense plate when plates converge.</p> Signup and view all the answers

<p>Huge pieces of crust that slowly move on the upper part of the mantle by convection.</p> Signup and view all the answers

<p>Deep and narrow depressions in the seafloor; form where the subducted plate moves into the mantle.</p> Signup and view all the answers

<p>Occurs when two tectonic plates move toward each other and collide.</p> Signup and view all the answers

<p>A depression of Earth's surface in which an ocean lies.</p> Signup and view all the answers

<p>Where new seafloor is made and a plate 'grows'.</p> Signup and view all the answers

<p>Where plates collide.</p> Signup and view all the answers

<p>Earth's crust below the seafloor.</p> Signup and view all the answers

<p>Crust below the continents.</p> Signup and view all the answers