U1L1: Plate Tectonics and the Rock Cycle

What is the theory of plate tectonics?

It is the scientific theory that the Earth's lithosphere is composed of a number of large, rigid plates which move over the asthenosphere.

What are the three types of plate boundaries?

Divergent boundaries, convergent boundaries, and transform boundaries.

What happens at divergent boundaries?

Plates move apart, magma rises to the surface creating new crust.

Give an example of a divergent boundary.

The Mid-Atlantic Ridge.

What occurs at convergent boundaries?

Plates move towards each other, resulting in subduction or continental collision.

What is an example of oceanic-continental convergence?

The Andes mountain range.

What characterizes transform boundaries?

Plates slide past each other horizontally with no creation or destruction of crust.

Give an example of a transform boundary.

The San Andreas Fault.

What are igneous rocks?

Rocks formed from the cooling and solidification of molten rock (magma or lava).

What is the difference between intrusive and extrusive igneous rocks?

Intrusive rocks cool slowly beneath the surface; extrusive rocks cool quickly on the surface.

What defines sedimentary rocks?

They are formed from the accumulation, compaction, and cementation of sediments, often in layers.

Provide an example of a sedimentary rock.

Sandstone.

What are metamorphic rocks?

Rocks that have changed from one form to another due to heat, pressure, or chemical reactions.

Name a key characteristic of foliated metamorphic rocks.

They have a layered or banded appearance.

How is the rock cycle driven by plate tectonics?

Plate tectonics facilitates the melting of rocks into magma, the uplift of mountains, and the transformation of rocks through pressure and heat.

What happens to rocks at divergent boundaries and subduction zones during the rock cycle?

Melting rock forms magma, which cools to become igneous rock.

How does weathering and erosion relate to sedimentary rock formation?

Uplift of mountains exposes rocks to weathering and erosion, creating sediments that form sedimentary rock.