Plate Boundaries

Where do metamorphic rocks form?

Under the surface of the earth

What happens at divergent boundaries that are located along two continental plates?

a valley like rift develops

What happens when lava cools quickly?

no crystals form and rocks look glasslike

How hot must a rock get to melt?

600 and 1300 C or 1000 and 2400 F

What is a convergent boundary?

A convergent boundary occurs where two plates are pushing toward each other

What is a divergent boundary

A divergent boundary marks two plates that are moving apart from each other.

What is a transform boundary

A transform boundary is when two plates slide past each other.

What do sediments do gradually over long periods of time

Accumulate in layers

How does a transform boundary produce an earthquake?

As the plates grind past each other, the jagged edges strike each other, catch, and stick, "locking" the plates in place for a time. Because the plates are locked together without moving, a lot of stress builds up at the fault line. This stress is released in quick bursts when the plates suddenly slip into new positions. The sudden movement is what we feel as the shaking and trembling of an earthquake

Why do we call the changes in the rocks a rock cycle?

Because it is never ending

How is extrusive rock different than intrusive igneous rock?

Cools quickly on the surface (extensive) magma cooled at a slower rate (Intrusive)

What is oceanic crust?

Crust that is found under the ocean.

List the six characteristics used ti identify rocks within these main classes.

Crystals, Gas bubbles, Ribbon Like layers, Fossil, Glassy surface, Sand and pebbles

Name two tectonic plates that form a boundary

Example: South American plate and Scotia Plate.

Name 2 examples of metamorphic rocks

Gneiss & marble

Give an example of a trench

Mariana Trench and Islands.

What is the difference between magma and lava?

Molten rock deep within earth (magma) magma that erupts onto the surface of a volcano (lava)

What happens at convergent boundaries, where an oceanic plate and a continental plate collide?

Oceanic crust tends to be denser and thinner than continental crust, so the denser oceanic crust gets bent and pulled under, or subducted, beneath the lighter and thicker continental crust.

What are 2 general characteristics of metamorphic rocks?

Ribbon Like layers & many have shiny chrystals

What happens at divergent boundaries that are located in the middle of the ocean?

Seafloor spreading

What are the three main types of rocks?

Sedimentary, metamorphic, and igneous

What forms where the oceanic plate and continental plate collide?

Subduction zone

What is a boundary?

The border between two tectonic plates is called a boundary.

What is continental crust?

The crust that underlies the continents.

What causes pressure on rocks?

Tons of other rocks pressing down creating pressure.

How do sediments get cemented together?

Water passing through the spaces in particles

Name 4 factors that wear down and break objects like rocks apart over time.

Wind, water, sun and temperature changes

Are the earth's continents constantly moving? Why?

Yes, they are constantly moving due to the motions of the tectonic plates.

What happens at convergent boundaries where two continental plates collide?

a collision between two continental plates crunches and folds the rock at the boundary, lifting it up and leading to the formation of mountains and mountain ranges.

Describe how rocks are heated

due to movement of the crust, rocks are pulled under the surface of the earth where temperatures are very high

What are three general characteristics of sedimentary rocks

fairly soft, crumble easy, sand, pebbles, or stones.

Name the 2 forces that cause metamorphic rocks to form?

heat & pressure

Give four examples of sediments

sand, shells, pebbles, other

What happens at convergent boundaries, where two oceanic plates collide?

the older plate is forced under the younger one — and it leads to the formation of chains of volcanic islands known as island arcs.

Give examples of geological phenomena we experience on Earth that are caused by the slipping, sliding, and colliding of tectonic plates.

volcanic eruption, earthquakes, tsunamis

Draw two arrows representing a convergent boundary:

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Draw two arrows representing a divergent boundary

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Draw two arrows representing a transform boundary

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