Download Igneous and Sedimentary Rocks

Warm-Up
Wednesday, September 19
Explain how a metamorphic rock changes
into a sedimentary rock?
Weathering (wind, water, and temperature changes) cause
rock particles to break off and erode away.
Particles are deposited in a different
location. Minerals cement them together
and pressure compacts them into a
sedimentary rock.
Igneous Rocks
form from the cooling of molten
rock (lava and magma).
Igneous rock
Intrusive rock
Extrusive Rock
• Magma
• Lava
• Inside Earth
• Earth’s Surface
• Cools slowly
• Large Crystals
• Cools fast
• Small Crystals
• Coarse-grained
• Fine Grained
• Ex: Granite
• Ex: Basalt
Are lava and magma the
same?
• LAVA is molten material found on
the surface of the earth.
• MAGMA is molten material found
inside the earth.
Classified by
Formation and
Texture
Formation:
1. Extrusive Rock is formed
from lava erupted onto Earth’s
surface.
Exits the Earth
(Basalt)
2. Intrusive Rock is formed
when magma hardens
beneath Earth’s surface.
Inside the Earth
(Granite)
PORPHYRITIC
• Rocks with two or more different sized
crystals are said to be PORPHYRITIC.
• The rocks cooled at two different rates
• Sometimes these rock are simply called
PORPHYRY
What type of rock is Stone Mountain made from?
Granite
2nd Largest batholith in the world.
Texture:
Fast Cooling Lava (Extrusive)
• Fine-Grained
• Small Crystals
• Gas Bubbles dissolved quickly
Pumice
Obsidian
Slow Cooling Magma (Intrusive)
• Coarse-Grained
• Large crystals
Granite
How do you use igneous rocks?
Tools
Buildings
Streets
Bridges
Gravel
Cleaning
Polishing
Gardening
An intrusive igneous rock would
have what type of texture? Why?
Coarse-Grained, large crystals.
It is hotter in the earth than on the
outside of the earth so it takes longer
for magma to cool down.
An extrusive igneous rock would
have what type of texture? Why?
Fine-Grained or glassy
texture
It is cooler on the surface of
the Earth so the rocks can
cool faster.
Sedimentary
• Sediments: Tiny pieces of ROCK
• Formed by:
– Erosion or weathering
– Deposition
– Cementation
– Compaction
– Compaction
Sedimentary
• Sediments: Tiny pieces of ROCK
• Formed by:
– Erosion or weathering
Sedimentary
• Sediments: Tiny pieces of ROCK
• Formed by:
Deposition
Sedimentary
• Sediments: Tiny pieces of ROCK
• Formed by:
– Compaction
Sedimentary
• Sediments: Tiny pieces of ROCK
• Formed by:
Cementation
TYPES OF SEDIMENTARY
We can classify sedimentary
rocks by the way in which they
form and their composition.
Let’s look closer…
CLASTIC
These rocks are made of pieces of other rocks.
Breccia
(angled fragments)
Conglomerate
(round fragments)
Sandstone
(Layers)
ORGANIC
• These rocks are
made of pieces of material
that was once alive.
MAY contain fossils…
Coal
Limestone
CHEMICAL
• These rocks form when
solutions containing
minerals evaporate.
Halite ,Gypsum
Sedimentary
• Form underwater when sediments are
cemented together. They have layers
(strata).
- Clastic—pieces of rock are cemented together by
minerals
– Chemical—minerals crystallize out of seawater
– Organic—from the remains of once living plants and
animals
Sedimentary Rocks
Breccia
(clastic)
Sandstone
(clastic)
Limestone
(organic)
Coal
(organic)