THE ROCK CYCLE

A REVIEW: THE PROCESSES THAT CHANGE

ROCKS• Weathering: breaks down rocks into tiny

mineral grains or sediments. • Erosion: moves the sediments by wind or

water. Layers of sediments pile up. Over time, the pressure of compaction turns the sediments into sedimentary rock. • Heat: Melts the rocks.• Pressure (Compaction): Compacts the

rocks together.

WHAT IS THE ROCK CYCLE

• The rock cycle shows how rocks are created and how they change over time• Each type of rock we have learned about can change into any of the other types of rocks

In your notes…

Igneous Rock

Metamorphic Rock

Sedimentary Rock

Let’s start with igneous rock

IGNEOUS ROCK SEDIMENTARY ROCK

• When LAVA cools, igneous rock is formed • This rock is then exposed to elements

such as wind and water• Wind and water can break down igneous

rock into smaller pieces called sediment

Let’s start with igneous rock

IGNEOUS ROCK SEDIMENTARY ROCK

• Over time those pieces of sediment compact and cement over time (compaction & cementation) to form…

Sedimentary rock!

Let’s start with igneous rock

IGNEOUS ROCK METAMORPHIC ROCK

• All rocks can be heated! AND…THE EARTH PRODUCES A LOT OF HEAT

• Inside of the earth there is heat from pressure and this heat bakes the rocks

• The igneous rocks below the earth’s surface do not melt, but they change form because the crystals in the rock change when subjected to heat

• Tectonic plate movement (more on this in quarter 2!) also produces a large amount of heat which then create mountains of metamorphic rock

Let’s start with igneous rock

Now let’s look at metamorphic rock

METAMORPHIC SEDIMENTARY

• METAMORPHIC ROCKS can turn into SEDIMENTARY rocks• This happens when metamorphic rocks are

exposed to the elements (wind/water) and break down into pieces of sediment• The sediment compacts into layers and

eventually new sedimentary rock forms

Now let’s look at metamorphic rock

METAMORPHIC IGNEOUS

• METAMORPHIC ROCKS can turn into IGNEOUS rocks• Rocks inside of the earth can melt

down into magma and eventually come out of the rock in the form of lava• When this lava hardens and cools, we

have IGNEOUS rock

Now let’s look at metamorphic rock

And finally…sedimentary rock

SEDIMENTARY METAMORPHIC

• SEDIMENTARY rocks can become metamorphic rocks• When sedimentary rocks are forced back

inside of the earth, the crystals within the rock change because of the intense heat

And finally…sedimentary rock

SEDIMENTARY IGNEOUS

• SEDIMENTARY rocks can become IGNEOUS rocks• At plate boundaries, or inside of volcanoes,

sedimentary rocks can melt down and become part of a lava stream• Once coming out onto the earth’s surface,

these rocks will be altered and now called igneous rocks

And finally…sedimentary rock