Download Rock Cycle Homework: Read 75-85 Do Cornell notes (key terms

What is a mineral?
2. What is a rock?
What powers the Earth’s rock
cycle?
How do fine grained igneous
rocks form?
1.
3.
4.
A
rock is any solid mass of mineral or
mineral-like matter that occurs naturally as
part of our planet.
• Some rocks are a single mineral, but most rocks are
combinations of minerals.
 Rocks
are classified into three major
groups:
1.
2.
3.
Igneous
Sedimentary
Metamorphic
 Igneous
rock is formed by the
crystallization of molten magma.
 Sedimentary rock is formed from the
weathered products of rocks that have been
transported, deposited, compacted, and
cemented.
 Metamorphic rock is formed by the
alteration of pre-existing rock deep within
Earth (but still in the solid state) by heat,
pressure, and/or chemically active fluids.
 Interactions
among Earth’s water, air, and
land can cause rocks to change from one
type to another. This continuous process
is called the rock cycle.
 Shows the interrelationships among the
three rock types
 Magma
is molten material that forms
deep beneath the Earth’s surface.
• When magma cools and hardens beneath the
surface or from volcanic eruptions, igneous
rocks form.
• Lava is magma that reaches the surface.
 Weathering
is a process in which rocks
are physically and chemically broken
down by water, air, and living things.
 Sediment
is weathered pieces of Earth
elements.
 Eventually sediments are compacted and
cemented to form sedimentary rocks.
 If the sedimentary rocks get buried deep
under the Earth it would be subjected to
extreme temperature and pressure. It
will then change into metamorphic rocks.
 Processes
driven by heat from the Earth’s
interior are responsible for forming both
igneous rock and metamorphic rock.
 Weathering and the movement of
weathered materials are external
processes powered by energy from the
sun.
 External processes produce sedimentary
rocks.
 Journey
through the Rock Cycle.
 How might a sedimentary rock become an
igneous rock?
• The rock could become buried at depths where
temperatures and pressures were great enough to
cause melting. When the melted material (magma)
cooled and hardened, an igneous rock would form.
 What
processes change sedimentary rock
into another sedimentary rock?
• Weathering, transportation, deposition, compaction,
and cementation
 Fire!
 Intrusive
igneous rocks are formed when
magma hardens beneath Earth’s surface.
• Erosion exposes these rocks.
• Magma has many elements and gases. As magma
rises, it cools allowing elements to bond and form
minerals,
• Granite is a common intrusive igneous rock.
 Extrusive
igneous rocks are formed when
lava hardens.
 Classified
Texture
by texture and composition
1. Coarse-grained texture is caused by slow
cooling resulting in larger crystals.
2. Fine-grained texture is caused by rapid
cooling resulting in smaller, interconnected
mineral grains.
3. Glassy texture is caused by very rapid cooling.
4. Porphyritic texture is caused by different
rates of cooling resulting in varied sized
minerals.
Composition
Granitic composition rocks are made mostly
of light-colored quartz and feldspar.
2. Basaltic composition rocks are made mostly
of dark-colored silicate minerals and
plagioclase feldspar.
3. Andesitic composition rocks are between
granitic light-color minerals and basaltic
composition dark-colored minerals.
4. Ultramafic composition rocks are made mostly
from iron and magnesium-rich minerals.
1.