Understanding Rock Strata

Rocks, Minerals, and Rock Cycle

By Jorge Diaz

• They are solid.

• They are made of one or more minerals.

• ​They come in all shapes and sizes.

​This is Dwayne "The Rock" Johnson. This is not a rock, kids!

Rocks are parts of the Earth's crust

Multiple Choice

A rock is...

• A solid piece of the Earth

• A Hollywood actor

• Always very very hard

• Made of water

They come from volcanoes and magma, and form because other types of rocks melt inside the Earth and then cool off.

Igneous

They come from sediments! Pieces of other rocks erode thanks to the wind and the rain and create rock's dust called sediments.

​​Sedimentary

​They come from other rocks when they are exposed to extreme heat and pressure.

​​Metamorphic

​There are 3 types of rocks

​Volcanoes are part of the rock cycle!

​They spew magma from inside the Earth. When magma is outside the volcano and on the surface, it's called lava.

Remember Plate tectonics from when we learned about earthquakes? Thanks to that, the rocks on the surface can be recycled over millions of years!​

Fill in the Blanks

Multiple Choice

Thanks to _________, the materials of the Earth's crust can be recycled

• Volcanoes

• Plate tectonics

• Earthquakes

• Lava

Multiple Choice

Which are the types of rocks that come from volcanoes?

• Igneous

• Sedimentary

• Clastic

• Metamorphic

​Sediments are awesome!

​The origin of sediments can be inorganic (not from living things, like other rocks) or organic (from living things, like plants, bones or seashells), so living things can create rocks too!

​

Sediments deposit in forms called layers, which are horizontal lines one over the other. It can help us calculate the age of a certain part of soil!​

​Sedimentary rocks must go through this steps to form

• Erosion is when larger rocks break little by little into small dust-like particles (sediments) because of rain and wind.

• Transportation is when the sediments are transported from the original rock to other places.​

• Deposition is when the sediments reach a place thanks to water or wind, and start accumulating.

• Compaction is when the sediments are pressed together by the weight of all the material above them.

Fill in the Blanks

Multiple Choice

What is the correct order of the steps in the formation of sedimentary rocks?

• Erosion > Deposition > Transportation > Compaction

• Compaction > Deposition > Transportation > Erosion

• Deposition > Compaction > Erosion > Transportation

• Erosion > Transportation > Deposition > Compaction

​Metamorphic sounds like metamorphosis, the process in which animals change forms in their life stages (like tadpoles into frogs, or caterpillars into butterflies).

Rocks change because of the pressure and extreme heat that they can get inside of the Earth.​ Because of this, they can be very hard.

​Metamorphic, the rocks of change

​Famous gemstones!

​Many known gemstones (like rubies and larimar which come from corundum and pectolite) come from metamorphic rocks (or minerals if we know exactly what they are made of).

​

Some of this rocks are also used​ in construction! marble is used a lot in kitchens and also to build sculptures!

Multiple Choice

What are some of the uses of metamorphic rocks?

• Construction

• Jewelry

• Arts

• All of the above

​A cycle that never ends

​cycles are processes that do not have an obvious beginning or end because they keep repeating.

​

Like​ the water cycle when water changes form and place but always comes back and start the cycle again, rocks do that too.

​

Igneous rocks over time can turn sedimentary rock, and they into metamorphic, and finally into igneous again!​

Draw

Draw the rock cycle!