A Rock’s Journey
First Steps
Igneous Rocks

Before rocks, there was
◦ Magma
 Molten crystals that flow like a liquid.

After these molten mineral grains cool, they
form a specific type of rock called
◦ Igneous rocks

These rocks come in three different and
unique forms
◦ Intrusive
◦ Extrusive
◦ Volcanic Glass
Igneous Rocks

Intrusive rocks
◦ Form in the depths of the Earth over
thousands of years

This time allows them to form very
◦ Large mineral grains
Igneous Rocks

When magma reaches the surface and
cools there, it forms
◦ Extrusive rocks

With very
◦ Small
◦ mineral grains
Igneous Rocks

The violence of volcanoes causes mineral
grains to be thrown into the air where
they cool so quickly they have
◦ Little or no
◦ Mineral grains

These rocks are called
◦ Volcanic glass rocks
Igneous Rocks

Although similar in general shape and
structure, these three types have different
“races” within them:
◦ Basaltic
◦ Granitic
◦ Andesitic
Igneous Rocks

Basaltic rocks are
◦ Dense, dark-colored rocks
◦ Formed from magma that contains lots of the elements
 Iron and magnesium

In opposition, granitic rocks are
◦
◦
◦
◦

Light colored rocks
With a
Lower density
Than basaltic rocks because it contains a lot of the
compound silica (SiO2)
Finally, there are those rocks which find themselves
with a bit of basaltic and a bit of granitic properties;
these rocks are called
◦ Andesitic
Igneous Rocks
Igneous Rocks
Metamorphic Rocks
Once rocks form solid and strong, they
must face the perils of this earth. Those
rocks that face the most extreme
conditions of earth form brilliant rocks
that are even stronger than before.
 These rocks are called

◦ Metamorphic rocks
Metamorphic Rocks

The rock that forms into the
metamorphic rock is called the
◦ Parent rock
Metamorphic Rocks

The same ingredient mineral grains take
on many forms depending on the amount
of
◦ Heat and/or pressure
◦ they experience
Metamorphic Rocks

Forces experienced by
rocks can come from
either the
◦ Weight of the Earth pressing
down on the rocks
◦ The extreme temperature
created near the Earth’s core
◦ Or the contact of the rocks
with hot lava, also called
magma
Metamorphic Rocks
These powers force the mineral grains to
flatten and move positions
 If the mineral grains form into layers, the
new metamorphic rock is called a

◦ Foliated rock

If, however, they move into random
positions, they are called
◦ Non-foliated rocks
Metamorphic Rocks

Foliated
Non foliated
Offspring becoming Parents
How metamorphic rocks are formed
Increasing Pressure & Temp
Categorizing Metamorphic Rocks
Sedimentary Rocks

Rocks formed when fragments of other
rocks come together to form a new rock
Sedimentary Rocks

Three types of Sedimentary Rocks
◦ Detrital
◦ Chemical
◦ Organic
Sedimentary Rocks

Detrital Rocks
◦ Steps of Creation
 1. Rock broken
 Weathering and Erosion
 2. Compaction
 Squeezed together
 3. Cementation
 Water drips between and solidifies
Sedimentary Rocks

Classified by size and shape
Sedimentary Rock

Chemical Sedimentary
◦ Rocks from solution
Limestone
&
Rock Salt
Sedimentary Rocks

Organic sedimentary rocks
◦ Made from once living material
Sedimentary Rocks

As humans do, some rocks will break up
with their partners and form new bonds
with new partners. These new blended
families are called sedimentary rocks. They
form from the broken, shattered pieces or
rocks and shells, called sediment, that have
been torn from their parent rocks by harsh
wind and raging water. These blended
families come in three very different
categories: detrital, chemical, and organic.
Sedimentary Rocks

The most common form is when pieces of
sediment are forced together under
pressure to form detrital rocks. This process
occurs in three stages. First, the rock is
broken down by weathering and erosion,
which is the movement of weathered
materials. Second, the sediments get closer
and closer through a process called
compaction. Finally, new water joins the mix
and solidifies the bonds through
cementation.These rocks are classified by
the size and shape of their sediments.
Sedimentary Rocks

Like people of the same race, rocks of the
same type are still vastly different from each
other. Out of solution come chemical
sedimentary rocks. These rocks form when
pieces of sediment that were dissolved in
water come together and form a solid rock.
Two examples of these rocks are limestone
and rock salt. The rocks that aren’t really
rocks are called organic sedimentary rocks
because they are made of once-living
material. Two examples of these rocks are
coal and chalk.
Rock Cycle

How rocks recycle
Rock Cycle