Let’s Rock!!
What’s a Rock?
The Uses of Rock
The Three types of Rock
The Rock Cycle
To learn how to insert intro music (highly recommended), click here.
What’s a Rock?
What do you think of when you
hear the word rock?
What you should think of is
a useful material that you
depend on and use
everyday.
Most people don’t realize
how important and useful
ordinary rocks are.
The next time you hear the word “rock” we want you to
think about the guy on the next slide.
What’s a Rock?
This is BIF.
He can’t “body slam” you.
He can’t raise his eyebrow,
(actually he doesn’t have
eyebrows) but he knows a
lot about rocks. That’s
because he IS a rock
What’s a Rock?
Here is a closer look at
BIF’s bands.
What’s a Rock?
Quartz (grey), Feldspar (pink), and Biotite
(black)
Mica (black), Quartz (grey), Feldspar (white), and
Hornblende (black)
A rock is a naturally formed solid that is usually made up
of two or more types of minerals.
In many rocks, like the granite pictured above, you can
see the different colored minerals that it is made up of.
What’s a Rock?
The minerals within a rock are also natural solids, but there are
two differences between rocks and minerals. First, rocks do not
have a crystal structure. You see, the atoms that make up a
mineral are arranged in a repeated 3-D pattern that results in
many minerals forming in flat-sided crystals, rocks don’t do this.
Did you notice that the two pieces of granite on the last slide
looked so different? This is because rocks lack a definite
chemical make-up. This means that the combination of minerals
in a certain kind of rock can be different. The amount of each
mineral also varies greatly. On the other hand, a certain mineral
always contains the same ingredients in the same amounts.
The Uses of Rock
Now that you know
what a rock is, let’s
talk about their many
uses.
You may not realize it,
but MANY things in
the world around you
are built using rocks.
The Uses of Rock
Rocks are used in buildings. Here are just a few of the
materials that come from rocks. You can find most of
these in your school or home.
Bricks and cinderblock are used for foundations and walls of homes. They are
made of ground up rock cemented together.
The cement and concrete that is used to hold the brick and blocks together is also
made of ground up rock.
Drywall is a material that is commonly used to cover walls and ceilings. If the
walls in your home aren’t made of wood, it’s probably drywall which is made of
ground up rocks.
Metal (from rocks) is used for the electrical wires, pipes for plumbing, and even
nails that hold together wood.
The Uses of Rock
Minerals found in rocks include many useful metals such
as copper, aluminum, chromium (chrome), silver, and gold.
Metal cans are used to can food and beverages.
The Metal used to make cars, their engines, your school bus, airplanes, and even
your bike come from rock.
Metal is used to make most of the tools that we use to make other things. Knives,
saws, axes, pliers, screwdrivers, and hammers are all made of metal that comes
from rock.
Metal is also used on both the outside and inside of all electronics such as cell
phones, ipods, computers, and video game systems.
The Uses of Rock
Rock also has many uses in jewelry and art.
Gold, silver, and other metals are used to make rings, necklaces, bracelets, and
watches.
Some gemstones used in jewelry are minerals.
Statues and monuments are carved from rock. Mount Rushmore, the Great
Pyramids, and the Great Wall of China are made of carved stone.
Pottery is made of clay from rocks, and many paints and dyes are made of
minerals obtained from rock.
The Uses of Rock
There are also many other everyday uses for materials
that come from rock.
Talc which is used for making baby powder is found in some rock.
Quartz is used to make glass for eyeglasses, windows, and glass jars.
Rocks provide flourite and calcite which is used in toothpaste.
Mineral-based make-up is becoming increasingly popular.
Salt is a mineral that comes from rock and is used for seasoning food and melting
snow and ice.
(So that you can still go to school! Hooray!!!)
The Three types of Rock
Rocks are classified according to how they formed. All rocks can be
classified into one of three groups.
One type of rock is called igneous rock. Igneous rocks are formed from
molten rock that has cooled and become new rock.
Some igneous rocks form at the surface when hot, liquid magma
reached the surface through a volcano (extrusive igneous rock).
Other igneous rocks form deep under the surface (intrusive igneous
rock). These rocks cool/form much slower. Therefore, they grow larger
mineral crystals.
The Three types of Rock
Examples of igneous rock include…..
Diorite is an intrusive igneous rock.
It formed slowly under ground
which allowed mineral crystals
time to grow.
Basalt an extrusive igneous rock.
Note that there are no noticeable
mineral crystals.
The Three types of Rock
Examples of igneous rock (continued)
Igneous rocks form larger
mineral crystals when they
cool and harden slowly
UNDERGROUND. This
rock is intrusive.
The Feldspar porphyry pictured above has clearly
visible mineral crystals within it. Do you think this rock
formed underground (intrusive) or on the surface
(extrusive)?
The Three types of Rock
The next type of rock is called metamorphic rock. Metamorphic rock
forms when heat and pressure change older rock to new rock. This
occurs when the heat does not get hot enough to actually melt the rock
(which would create an igneous rock).
Both igneous and sedimentary rock can morph/change into metamorphic
rock. In fact, one type of metamorphic rock can change into a different
type of metamorphic rock as heat and pressure increases. The new
rock can then morph again (and again) as heat and pressure build with
the development of new rock above.
During the morph, bonded atoms in the rocks minerals can break apart
and new bonds are formed. This is called recrystalization.
The Three types of Rock
When metamorphic rocks change foliation often
occurs. Foliation is an arrangement of minerals in flat
or wavy parallel bands. In other words, you can see
lines or stripes running across the rock.
Not all metamorphic rocks are foliated. Nonfoliated
metamorphic rocks occur if a rock is made up of only
one mineral, or if it formed under less pressure.
Look at the metamorphic rocks pictured on the
following slides. Look for signs of foliation (visible
bands).
The Three types of Rock
Examples of metamorphic rock include…..
Gneiss is a FOLIATED rock.
You can tell by the bands of
minerals
Gneiss consists of the minerals quartz,
feldspar, and mica. If often forms from
granite (igneous rock) that morphed. Do
you see signs of foliation?
Marble is a NONFOLIATED
rock. There are no bands
Marble starts out as the
sedimentary rock limestone.
Limestone is composed almost
entirely of one mineral, Calcite.
Therefore, there is NO foliation
of minerals.
The Three types of Rock
Another example of metamorphic rock
This sample of Phyllite is made
of the minerals quartz, mica and
chlorite. Does Phyllite shows
signs of foliation?
Phyllite is a FOLIATED
metamorphic rock.
Remember the bands of
minerals in metamorphic
rocks can be bent by heat
and pressure beneath the
Earth.
The Three types of Rock
The last type of rock is called sedimentary rock. Sedimentary rock forms
when pieces of older rocks, plants, and other material on the surface get
pressed or cemented together.
The small broken pieces of rock are a result of moving air and water.
These pieces form layers that pile on top of each other over long periods
of time (thousands or even millions of years).
As new layers pile up, lower layers get pressed together by the weight of
the layers above.
The Three types of Rock
Sedimentary rock (continued)
The layers look similar to the bands of metamorphic rocks. However,
sedimentary rocks form under much less pressure. Therefore,
sedimentary layers are grainy and the grains can usually be scraped
loose rather easily.
The bands of minerals in metamorphic rocks on the other hand, form
under immense pressure and heat. The mineral bands often have welldeveloped crystals. Metamorphic rocks tend to be harder and aren’t as
easy to scrape.
The Three types of Rock
Examples of sedimentary rock include…..
This sandstone pedestal is probably a small
part of what use to be a much bigger rock
formation.
Moving water, hot and cold temperature
changes, and wind have carved away the
formation and broken the sand grains apart
again.
This is a conglomerate.
Conglomerates are sedimentary
rocks with large pieces of older
rock still visible.
The large pieces are cemented
together by other dissolved mineral
that have reformed in the space
between.
The Three types of Rock
Examples of sedimentary rock (continued)
Limestone is a sedimentary rock that is
made of the shells and skeletons of tiny
organisms that once lived in shallow
seas.
Over time, the minerals in the shells and
skeletons blend as they dissolve and
reform repeatedly. Calcite dissolves
easily and most underground caves are
formed when ground water washes away
limestone under the surface.
The Three types of Rock
Examples of sedimentary rock (continued)
Remember BIF? He is a sedimentary rock too.
His “bands” are actually
layers of sediment that
formed in a shallow area of
an ocean next to a
continent. This sediment
drifted to the bottom of the
ocean, piled up, and got
pressed together.
The Three types of Rock
When you look at how the three types of rock are spread
throughout the Earth’s crust, you find that they are not spread
evenly.
When you look at the surface of the crust, you find that 75% of
the rock is sedimentary. That means there is three times more
sedimentary rock than igneous and metamorphic COMBINED.
If you think about how each rock forms, that makes sense.
What would happen to an igneous or metamorphic rock on the
surface of the Earth?
That’s right. It would be exposed to wind and rain. Over time,
it would break apart. Those pieces would get pressed together
to form sedimentary rock.
Rocks on the Surface of the Earth
Igneous and
Metamorphic
Rock (combined)
25%
Sedimentary Rock
75%
The Three types of Rock
On the other hand, when you look at all of the rock that makes up the
ENTIRE crust of the Earth, you find that 95% of the rock is igneous and
metamorphic. That means that only 5% of the crust is sedimentary rock.
Once again, if you think about how each rock forms, that makes sense.
What kind of conditions would you begin to find at just 10 or 20 feet
underground?
That’s right. It would start to get warmer and pressure from the rock and
dirt above would start to build. Even at it’s thinnest points, the Earth’s crust
is 4-7 miles thick. Some places are over 40 miles thick.
What type of rock would form underground where heat and pressure build
quickly? That’s right metamorphic and igneous rock.
Rocks of the Entire Crust of Earth
Sedimentary Rock
Igneous and
Metamorphic Rock
(combined) 95%
5%
The Rock Cycle
Most people think of rocks as being constant and never changing.
However, rocks do change. The reason that people don’t think of
this changing is because most rocks only change over thousands,
often millions, of years.
The rock cycle is a set of natural processes by which rocks form,
breakdown, change, and reform.
A cycle is a set of events/changes that occur repeated over and
over again. Other examples of cycles would include: The water
cycle, the Moon phases, and seasons.
The Rock Cycle
Some cycles consist of a predictable sequence of events that
always occur in the same order.
However, the changes in the rock cycle DO NOT occur in a
predictable order. As you will see in the next slide, any rock in the
cycle can change in two or three different ways.
Which came first the chicken or the egg? Like all cycles, there is no
beginning or end to the rock cycle, and the cycle goes on
continually.
To explore the processes of the Rock Cycle
more (WITH NOTEBOOK), click here.
(You may have to change this hyperlink after it has been downloaded. If you need
help, send me a message through the TPT site, or just use the NOTEBOOK
program separately, it is included in the zip file.)
To explore the Rock Cycle within this
presentation click here.
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I have inserted a “Sound and Music” link at the beginning of the
presentation. However there is no music in the powerpoint itself. It’s
probably not entirely legit for me to include it in the presentation
anyway, since it isn’t my music to give. However if you have an
appropriate song (in digital format) it is easy to attach. I recommend
“We Will Rock You” by Queen, but there are many “rock” songs that
would be appropriate. I highly recommend this, it is only set to run for
the first four introductory slides, but it really gets the kids’ attention.
Click again to view the three simple steps to
starting your presentation off with a bang.
Step 1 Download the song of your choice and attach a short-cut to your desktop.
Just click and drag the song in iTunes or other music player onto the lap-top.
Step 2
Open the powerpoint and double-click on the
question mark at the bottom
right of slide #1.
Step 3 When the window pictured below opens, choose desktop, find and click
on the song, then click the “choose” button in the bottom right (circled below).
You will have to do this each time you close and reopen the
presentation, the link is not permanent. Slightly
inconvenient, but it only takes a few seconds to do.
Return to slide #1