Download 53 Rock Cycle2

The
Rock Cycle
Earth’s Crust
The whole earth is made of rocks & minerals.
Inside the earth there is a liquid core of molten
rock and on the outside there is a hard crust.
If you compare the earth to an egg, the shell on
an egg is like the crust on the earth.
The crust is made up of rocks and minerals.
Much of the crust is covered by water, sand, soil
and ice.
If you dig deep enough, you will always hit rocks.
Below the loose layer of soil, sand & crumbled
rocks found on Earth is bedrock, which is a solid
rock.
Earth’s Crust
The Crust makes up less than 1% of the Earth’s mass (0.4%)
There are 8 elements that make up 99% of the Earth’s crust.
It is made of oxygen, magnesium, aluminum, silicon, calcium,
sodium, potassium, and iron.
The continents are about 35 km thick and the ocean floors
are about 7 km thick.
The Mantle is the solid casing of the Earth and is about 2900
km thick.
It makes up about 70% of the Earth’s mass (68.1%).
It is made up of silicon, oxygen, aluminum and iron.
The Core is mainly made of iron and nickel and makes up
about 30% of the Earth’s mass (31.5%).
The Outer Core is 2200 km thick and is liquid and the Inner
core is 1270 km thick and is solid.
Elements in the
Earth’s CRUST
Element
Amount
Oxygen
47 %
Silicon
28.2 %
Aluminum
8.23 %
Iron
5.63 %
Calcium
3.5 %
ROCKS
The rocks you see around you - the mountains,
canyons & riverbeds, are all made of minerals.
A rock is made up of 2 or more minerals.
Think of a chocolate chip cookie as a rock.
The cookie is made of flour, butter, sugar &
chocolate.
The cookie is like a rock and the flour,
butter, sugar & chocolate are like minerals.
You need minerals to make rocks, but you
don't need rocks to make minerals.
All rocks are made of minerals.
MINERALS
A mineral is composed of the same substance
throughout.
If you were to cut a mineral sample, it would
look the same throughout.
There are about 3000 different minerals in
the world.
Minerals are made of chemicals - either a
single chemical or a combination of chemicals.
There are 103 known chemical elements.
Minerals are sorted into 8 groups.
Common Minerals
• Native Elements ~ copper, silver, gold, nickel-iron,
graphite, diamond
• Sulfides ~ sphalerite, chalcopyrite, galena, pyrite
• Halides ~ halite, fluorite
• Oxides & Hydroxides ~ corundum, hematite
• Nitrates, Carbonates, Borates ~ calcite, dolomite,
malachite
• Sulfates, Chromates, Molybdates, Tungstates ~
celestite, barite, gypsum
• Phosphates, Arsenates, Vanadates ~ apatite, turquoise
• Silicates ~ quartz, almandine garnet, topaz, jadeite,
talc, biotite mica
What are the three
types of rocks?
• Igneous
• Sedimentary
• Metamorphic
IGNEOUS ROCKS
• Forms from cooled lava.
• Most have crystals… the size of the crystal
depends on how fast the lava cooled.
- Slow cooling = large crystals
- Fast cooling = small to microscopic
• Some rocks have pores (like a sponge) from the
gases in the lava escaping during the cooling
process.
Uses of Igneous Rocks
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Road building materials
Gravestones
Creating lasting monuments
Used as an abrasive in polish things.
For trim and decoration in buildings.
Decorative landscape stone.
Jewelry
IGNEOUS ROCKS
Granite
Pumice
Obsidian
Gabbro
SEDIMENTARY ROCKS
• Formed from weathered igneous and
metamorphic rocks that are compacted
and cemented together!
• Usually layers can be seen.
• Some are conglomerates… i.e. you can
see smaller rocks or shells embedded.
Uses of
Sedimentary Rocks
• Gypsum is used to make plaster of Paris
and in drywall.
• Sandstone and limestone are used as
building stones.
• Limestone is also used for hard core
cement roads.
SEDIMENTARY ROCKS
Conglomerate
Limestone
Shale
Banded-Sandstone
METAMORPHIC ROCKS
Formed within the Earth… rocks that
change under an extreme amount of
heat and pressure.
These rocks are usually very dense
rocks.
Uses of
Metamorphic Rocks
• Used for pool table tops
• Carved into statues
• Buildings materials (floor tiles roofing
tiles and counter tops)
• Jewelry = Diamonds
METAMORPHIC ROCKS
Marble
Mica Schist
Slate
Quartzite
Most Common Rocks and
Minerals found in Delaware
• Calcite
•Quartz
Most Common Rocks and
Minerals found in Delaware
•Mica
•Feldspar
• Hornblend
Rock Cycle
Cooled
lava
Cemented
Layers
Heat and
Pressure
The Importance of
Rocks and Minerals
Igneous
Obsidian
Used in making arrowheads and knives
Basalt
Used in road building materials
Pumice
Used in scouring, scrubbing, and polishing
materials
Granite
Used for buildings, monuments, and
tombstones
The Importance of
Rocks and Minerals
Sedimentary
Sandstone
Used in the building industry for houses
Gypsum (mineral)
is used to make plaster of Paris and in
drywall
Limestone
is also used for hard core cement roads.
The Importance of
Rocks and Minerals
Metamorphic
Marble
Used in building, floors, tile in
bathrooms
Slate
Used for
roofs, chalkboards, patio walks and pool
tables
The Importance of
Rocks and Minerals
Minerals
Calcite
Used in cements and mortars and the
production of lime
Quartz
Used in making glass, electrical
components, and optical lenses
Igneous rock forms in
two ways!
Intrusive
Extrusive
- Forms from magma
cooling and solidifying
inside the earth’s
crust.
- Forms from lava
cooling and solidifying
outside of the earth’s
crust.