Download What is a rock?

THE EARTH ROCKS!!!
Chapter 3- Section 1 Rocks
Turn to page 58
Please take notes on yellow slides!
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What is a rock?
 You may be walking along and find
an interesting rock. You pick it up
and notice that it contains many
different particles or crystals. Some
of the particles may reflect light and
others may be dull.
The sparkles or crystals you see are
actually individual minerals. For
example, if you were to take a close
look at the rock, granite, you would
see crystals of feldspar, hornblende,
mica, quartz and other minerals.
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Rocks – a mixture of minerals, rock
fragments, volcanic glass, organic matter,
or other natural materials.
This is a granite rock
There are many uses of granite!
Carved into the Black Hills of South
Dakota are the iconic faces of four
former presidents of the United
States--George Washington, Thomas
Jefferson, Theodore Roosevelt, and
Abraham Lincoln. These men were
chosen to represent the first 150
years of American history and
America’s cultural heritage.
The idea came from Doane Robinson
to promote tourism in South Dakota
and his idea was wildly successful-the park attracts almost 3 million
park visitors every year.
This is granite!
Chew on this…
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Many of us have rock collections OR some
interesting rocks that we have found.
Because we are fortunate to live by Lake
Michigan, we can get cool rocks just by
walking down the beach.
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Discuss with your partner a cool rock you
may own OR perhaps a rock collection that
you have.
Chapter 3 – Section 1 Rocks
Rock – a mixture of minerals, rock
fragments, volcanic glass, organic
matter, or other natural materials
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All rocks are made of 2 or more minerals,
but minerals are not made of rocks.
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MINERALS
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A mineral is the same all the way through.
That is one reason we speak of
a sample or a specimen rather than a rock.
There are about 4000 known minerals on
earth.
All rocks are made up of 2 or more of these
minerals.
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Rocks are in a cycle…
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This means they continually
are changing into different types
of rock. The rock cycle is the
process that creates and changes rock.
The rock cycle shows the three
types of rocks – igneous,
metamorphic, and sedimentary
The Rock Cycle
Rock cycle – the process that creates
and changes rock.
Rock Cycle – the process
that creates and changes
rock
Sedimentary Rock is . . .

Rock formed
when layers of
small particles
of shell, rock,
and sand join
together.
Metamorphic Rock is . . .
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Rock that is formed
when pressure and
heat create changes to
sedimentary or igneous
rock.
Igneous Rock is . . .
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Rock that is formed
when melted rock cools
and hardens.
Three types of rocks
Igneous
Sedimentary
Metamorphic
Yes, over
time
limestone can
change into
gneiss which
can change
into
granite….
See rock cycle on pg. 59
Notice that rocks change
through many processes.
Heat, pressure, melting,
cooling,
weathering/eroding,
compaction and
cementation
On page 59 notice….
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This diagram looks different than the others in this
powerpoint.
You must always carefully look at the rock cycle
diagram being used…
they are not all the same. Each type of rock can
be in a different spot so you need to look carefully
and read what the arrows are saying!
On page 59 which type of rock is at the top?
sedimentary
In this diagram notice where sedimentary
is..yes, at the bottom, not the top like on
page 59!
Here’s a short movie about the rock
cycle…
Why do rocks change into different types
of rock?
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Many reasons such as
Heat
Pressure
Melting
Cooling
Weathering
Eroding
Compaction/cementation
Ex: Sedimentary rocks
can change when heat
and pressure are
added to make a
metamorphic rock
Ex:
Metamorphic
rocks can melt and
cool to form igneous
rocks
Ex:
Igneous rocks
can be broken into
fragments
(weathering/erosion)
to form sedimentary
rocks
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Use the chart AND get with your partner and
discuss…
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1. Explain how and igneous rock can change into a
metamorphic rock
2. Explain how a sedimentary rock can change into an
igneous
3. Explain how a metamorphic rock can change into a
sedimentary rock
Rocks become
bigger . . .
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, and bigger, and bigger, and
bigger
By earthquakes
By volcanoes
By heat and pressure
Rocks become smaller, and smaller, and
smaller, and
...
smaller
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By erosion
By wind
By earthquake
By floods
By rain
By slides
By man
Some processes
that change rock:
Heat/pressure
Weathering/eroding
Compaction/cemention
Cooling
Melting
Matter and the Rock Cycle
Rocks will weather and erode
and wind, water, or ice can carry
away these particles.
These particles are not lost or
destroyed – the particles are just
redistributed in other forms.
Conservation of matter –
the rock cycle never destroys
elements of rocks but merely
redistributes them.
So matter is never created or
destroyed.
Conservation Of Matter
– the rock cycle never destroys
elements of rocks but merely
redistributes them
Matter is never created nor destroyed
James Hutton is known
as the father of modern
geology. Geology is the
study of the earths rocks
and minerals. He was a
Scottish physician who
first noticed in 1788 that
rocks undergo profound
changes.
He noticed that layers of rock in
Siccar Point in Scotland had
been altered since their
formation. He noticed that some
of the layers were tilted and
partly eroded and not in nice
layers like they once were.
However, the younger rocks
above them were nearly
horizontal like the older rocks
once were.
This is a picture of Siccar Point!

James Hutton, a Scottish physician, first noticed in
1788 that rocks go through changes
As a general rule..
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Oldest rock is at the bottom…IF IT IS AN
UNDISTURBED SEQUENCE OF ROCK…
Here’s a short a video about the law of
conservation of matter….
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Rock Words: There are many common names for
rocks and the usually give you an idea of how big
the rock is. Here are a few:
mountain - huge, giant hunk of rock that is still
attached to the earth's crust, doesn't move, tall
boulder - large, taller than a person
rock - large, you could get your arms around it or a
bit smaller but it is usually jagged,
broken off a bigger piece of rock
river rock - round rocks that are along the edge &
at the bottom of fast-flowing rivers
stone - medium, you could hold it in two hands
pebble - small, you can hold it with two fingers,
could get stuck in your shoe, usually rounded