Transcript Earth Processes Part 1: Lithosphere

Earth Processes: Part 1:
Lithosphere (land)
•The student will be able to describe types of
rocks and the processes involved in the rock
cycle.
•The student will be able to explain the theory of
plate tectonics and how it relates to the formation
of volcanoes and earthquakes.
Geology
=
the
study
of
the
earth
Geology = the study of the earth
(lithosphere)
Minerals – naturally occurring solid elements
Minerals
– naturally
occurring
and compounds.
Can be
made upsolid
of all same
elements
anddifferent
compounds.
thing or two
things.
FYI:
toto
rocks
as as
letters
are are
to words.
FYI:minerals
mineralsare
are
rocks
letters
to
Minerals
up rocks!
words. make
Minerals
make up rocks!
Letters
Lettersmake
makeupupwords!!
words!!
Rocks are usually
Rocks
usuallymixtures
mixturesofof2 or more
2minerals.
or more minerals.
Some minerals can form….
Three Main Groups of Rocks

Igneous rocks-form from extremely
hot melted rock material-MAGMA
(ex: granite)

Sedimentary rocks-made of mineral
grains that become cemented together,
under pressure, forming solid rock
(ex: limestone)

Metamorphic rocks-formed by
changes (extreme heat/pressure) in
sedimentary or igneous rocks (ex: marble)
Sedimentary rock
example: Sandstone
Igneous rock
example: Granite
Metamorphic rock
example: Marble
PROPERTIES OF ROCKS
•COLOR -this is the least beneficial property
to use, especially all by itself.
For example, if you have two white
rocks…does that mean they are the same type
of rock?
•STREAK-color of pulverized substance,
usually tested on tile by trying to “write” with
it.
•LUSTER-quality and intensity of
light reflected…how shinny or dull is
it???
•HARDNESS-ease or difficulty in
which it can be scratched.
Mohs’ Hardness Scale
Scale from 1 - 10 that ranks
how hard or soft a rock is…
used as a reference to compare
.
1 is the softest and
10 is the hardest
•CRYSTAL FORM- definite geometric
relationship
•foliated = distinct parallel layers/bands
•non-foliated = NO distinct layers
•CLEAVAGE-the ability of a mineral to
break along preferred planes. (clean break)
•FRACTURE-the way a substance breaks
where not controlled by cleavage (uneven
break)
•DENSITY OR “HEAVINESS”
•HOW DOES IT REACT WITH CERTAIN
CHEMICALS…ACID??
•All these properties are used together to
identify rocks…never use just one by itself
ROCK CYCLE - All rocks go through a cycle,
constantly changing shape due to weathering, erosion,
heat, pressure, hardening and cooling.
They can change from one type of rock to another.
(For example, a sedimentary rock will not always be a
sedimentary rock.)
Weathering-the breaking down of rocks by weather.
There are two types of weathering:
Physical weathering (rocks broken)
Chemical weathering (composition changed)
Erosion -the process by which Earth materials are
moved from one place to another.
•Wind (rain, waves), water, gravity, ice, organisms
Plate Tectonicsplates of the earth move about on earth,
carrying continents and ocean floor with them.
PANGEA – all continents were once one entire
land mass; one continent
Due to Continental Drift /Sea Floor Spreading
the continent was broken apart and drifted
apart in ocean to where they are today.
Movements can occur between plates. These
movements can cause earthquakes, mountains,
volcanoes, and continental drift.
Fault-zone of weakness in the crust, along which
some movement of rock takes place.
There are three types of movements:
Divergent - plates moving away from each other
(produces sea floor spreading)
Convergent - plates moving towards each other
(produces volcanoes and mountains)
Transform - plates moving parallel to each other
in opposite directions (produces earthquakes)
Sea Floor Spreading
Results from an earthquake…..
Transform Plate Movement (side to side)


San Andrea's
Fault…What type
of movement is
this do you think?
Volcanoes-an opening in the crust through
which magma from within Earth flows out as
lava (formed from convergent plate movement)
Magma = underground
Lava = above ground
Volcanoes contain a “Zone of weakness”. This
zone is like a fault down under and when plates
put pressure on it, they push up
magma.(subduction zone)
Old
remains of
volcano
conduit