Transcript Rocks and Fossil Fuels

Rocks and Fossil Fuels
Think about rocks.
What do rocks look like?
Is this what you thought of?
Or this?
OR THIS????
OR…. THIS!!!!
Rocks can be small or big!
We are going to learn 3 different
rocks and how they are made!
Igneous Rock
Comes from melted rock like
magma
There are lots of different igneous
rocks because sometimes minerals
get mixed in before it hardens.
Also, igneous rocks look different
depending on how fast they cool.
If a rock cools quickly, there is no
time for large mineral grains to
form.
If it cools slowly… what do you
think?
Examples of igneous rock:
granite
This rock must have cooled slowly
because of all of the mineral grains in it
Hint: Granite sounds like GRAINS!
This rock is obsidian, it is smooth.
Did this rock cool fast or slow?
FAST!!
There wasn’t time for large
minerals to form
What about basalt? It has tiny, tiny
mineral grains but it is mostly smooth.
Yes, this rock must have cooled quickly
The second type of rock is called:
Sedimentary Rock
Sedimentary rock forms
from layers of sediment.
Sediment is tiny bits of weathered
and eroded rock.
Sediment can even be once living plants or
animals!
Sediment is rocks and other things
that have SETTLED together,
like at the bottom of a lake or river.
Settled = Sediment
This is weathered rock that has
eroded and settled on the ground.
THIS IS SEDIMENT
Sedimentary rock is made of layers,
CAN YOU SEE THE LAYERS??
For thousands, even millions
of years, little pieces of our
earth have been eroded-broken down and worn away
by wind and water. These
little bits of our earth are
washed downstream where
they settle to the bottom of
the rivers, lakes, and oceans.
Layer after layer of eroded
earth is deposited on top of
each. These layers are
pressed down more and
more through time, until the
bottom layers slowly turn
into rock.
Each layer can be a different mixture
of sediment.
Shale is sedimentary
Metamorphic Rock
Rock that has been changed by
heat and pressure
SQUEEZING!