Download The Rock Cycle - Valhalla High School

The Rock Cycle- its story
Formation of Rocks in More Detail
See p6 ESRT
C
Rock Cycle in Earth’s Crust
Depo
s
and B ition
uria
l
/or
and
n
o
cti tation
a
p en
m
o em
C
SEDIMENTARY
ROCK
M e lt in g
athe
r
( U pl
ift)
ing &
E ro s i
on
Pressure
t and/or
a
e
H
orphism
Metam
n
l i f t) r o s i o
p
(U
&E
g
n
i
r
the
Wea
lting
Me
at
io
METAMORPHIC
ROCK
IGNEOUS
ROCK
n
re
ss u
H
e
r
e
a
P
t
r
a
o
/
n
d
is m
M e ta m or p h
We
( U p l if t )
n
Weathering & Erosio
SEDIMENTS
E r o s ion
• To Read the
Rock Cycle,
follow the
arrows around
Me
ltin
g
MAGMA
S
di
o li
fi c
Start with Magma, these are types of
Igneous Intrusions which will become
Igneous Rock
Sometimes pieces of the surrounding
rock remain unmelted and become
part of the igneous rock (xenolith)
Igneous Intrusions-cut through the
parent rock
Making Sediments and Sedimentary
Rock…
•
•
•
•
•
•
•
Uplift
Weathering
Erosion
Deposition
Burial
Compaction
And Cementation (natural glue- silica, calcite
or iron oxides)
Sediment Sorting in Land Derived
Sedimentary Rocks
Sorting of sediments produces
separation of the particle
sizes(p6)
• Pebbles/gravels are dropped first
(form conglomerate)
• Sands (form sandstone)
• Silts, clays are dropped last (form
shale)
Chemical Origin in Chemically formed
Sedimentary Rock
• Water contains dissolved minerals, which can
fall out of solution (precipitate) due to
evaporation or chemical action
• Limestone can be formed from tiny grains of
calcite deposited from sea or lake waters
• Other examples are rock salt (halite) and rock
gypsum
Organic Origin
• Calcite is dissolved out of rocks
on land, carried to an ocean or
lake, and taken out of the water
by shell-producing organisms (eg.
Clams, oysters, sea snails)
• When these organisms die, their
shells pile up and are broken
down into fragments, and can
form organic limestone
Metamorphism…
• Metamorphic rocks are not formed from
magma or sediment
• Metamorphic rocks “morph” (change) from
existing rock, due to heat, pressure and
chemicals
• Pressure squeezes grains closer together
(more dense, less porous)
• Heat and chemicals may rearrange the
particles (new minerals may be formed)
Types of Metamorphism
Regional Metamorphism: large areas of rock
are under intense heat/pressure, which occurs
during mountain-building
• Heat comes from friction of rocks, and
pressure from overlying weight and the
squeezing of moving rocks
Contact Metamorphism: when hot magma
forces itself into overlying rock (intrusions)
and bakes the rock
Contact Metamorphism
Results in Folations if more then one
mineral makes up rock
• Occurs when the
pressure on the rocks
squeezes minerals into
parallel layers
• The rocks tend to split
easily along these layers
What is the Rock Cycle?
• Is the repeated series of events by which rock
gradually and continually changes from one
type to another
• Theses events are geological events-meaning
they happen in the Earth’s crust or on it
• Another word to describe this is geologic
process
• Can you name some of these processes?
Reading the Rock Cycle Chart
• See page 6-7 in the ESRT
• First Classify your Rock Samples-work together
with your partner
• Place them on the Rock Cycle diagram
enlarged copy-work together to complete Part
II of Lab
Complete Understanding the Rock
Cycle
1. When granite changes into schist, what geologic processes does it have to
undergo?
2. Change gneiss into conglomerate, which geologic processes are involved?
3. Which type of rock can change into the same kind of rock without going
through the entire rock cycle?
Sum Up:
• What are 3 great “truths” about the Rock
Cycle? Think about everything we talked
about today and see if you can list them
below:
Sum Up: (well maybe 5 truths…)
1. The Rock Cycle is a model of the natural changes
that occur in rocks and rock material
2. Shows all Rocks are made from other rocks or
rock remains
3. Shows Rocks are classified upon basis of
formation
4. Shows that there are a variety of ways that rocks
can change at the surface or within the Earth
5. It keeps on going and going….and has been since
the Earth’s Spheres formed
Food for thought…
• Do we have any influence on the Rock Cycle?
If so, what?
• What force is driving the Rock Cycle?