s3 o2 lesson rock cycle powerpoint

The

Ro c k C y c l e

Prepared by the Michigan Department of Environmental Quality
Office of Geological Survey


What is the

Ro c k C y c l e ?


Rock Cycle

explains
how Rocks and Natural Processes
are related
The

weathering

Sedimentary

pr
e

ing

ss
ur

e

lt
me

,h
ea

t

Metamorphic

Igneous


A more traditional definition is:

Rock Cycle
is a sequence of events involving the
formation, alteration, destruction, and
reformation of rocks as a result of
natural processes ...
Glossary of Geology, Bates & Jackson, AGI


We will use the graphic seen in
the background to help
represent the Rock Cycle.
There are many ways to show the various
relationships between the rocks and

the related natural processes.


Before we look at the

Rock Cycle
in detail,

let’s review some basic information …


The Rock Cycle involves the
recognition of three main
classes of rocks.

The three rock types are …


Sedimentary
CEMETERY
Rocks

Metamorphic
METABOLIC
Rocks

Igneous
INGENIOUS
Rocks

Right?


The eminent 18th century
lawyer, doctor, gentleman
farmer and founder of
modern geoscience,

James Hutton,

developed the concept of
the Rock Cycle to show
how rocks and natural,
physical processes are
interrelated.


The understanding of the world in the 18th century
was different from today …


Hutton knew about solar energy
and gravity at the surface.
He did not know about
radioactive heating
from inside the earth.
Solar energy, gravity and
radioactive heating are the major
forces driving the Rock Cycle.
As a result, the Rock Cycle

will be self-sustaining for
thousands of millions of years.


How does an antique concept like the Rock Cycle hold up in
light of contemporary data and scientific thinking?


Of special interest is Plate Tectonics.


The mantle, crust and surface of the earth
can be thought of as a giant recycling machine;
rocks are neither created nor destroyed,
but redistributed and transformed from
one rock type to another.

S

M

I


If you were to ask a geologist
what the earth is …

What do you think the
response would be?

Diagram of the Interior of
the Earth
Crust

0 to 40 km

0°C

Upper Mantle

40 to 670 km
1,000°C

Lower Mantle
670 to 2,890 km
2,000°C

Outer Core

2,890 to 5,150 km
3,700°C

Inner Core

5,150 to 6,370 km
4,300°C


Now that we better understand the

largest components of Geology …

lets move to some of the
smallest components of Geology …


There
is a hierarchy
to the
Atoms
make up elements.
elements of Geology
Elements combine to form
the natural compounds.

.

Natural compounds
and elements combine
to form minerals.
Minerals make up rocks.
Rocks make up the Earth.


Atomic Theory proposes that all matter is
composed of the atoms of about 100 different
chemical elements. It further proposes that
chemical compounds are formed by the combination
of the atoms of different chemical elements.

Elements can be arranged, based on their
identifiable properties, into the Periodic Table


O
Na Mg
K Ca

Only

Al Si
Fe

eight elements make up over 98%
of the earth’s crust!


There
is a hierarchy
to the
Atoms
make up elements.
elements of Geology
Elements combine to form
the natural compounds.

.

Natural compounds
and elements combine

to form minerals.
Minerals make up rocks.

What are Minerals?
Rocks make up the Earth.
How can we tell what they are?


The identifiable characteristics
of

Minerals are

naturally occurring inorganic elements or compounds
having an orderly internal structure
and a characteristic chemical composition,
composition
crystal form and
physical properties of a solid


Minerals combine to form Rocks


Some Rocks are made up of just one mineral like the sedimentary rock salt (made up of
the mineral halite) that is mined near Detroit.
Others Rocks are made up of many

granite
gneiss,

minerals - like the igneous rock
and the metamorphic rock
found near Marquette.


Now that some of the basics
have been covered, lets
consider some of the
details about the

Ro c k C y c l e