What is distinctive about this rock formation

Journal Entry
• Open books to P. 116-117 to analyze
picture and answer questions
– What is distinctive about this rock formation?
– What does the shape of this rock formation
suggest about how it was formed. ( How do you
think it was formed?
– Where do you think this is?


Rocks
• What is a rock?
– Rocks and Minerals are often confused. It is
important to understand the difference.
– A rock is: ________________________


3 types
• Igneous- from cooling magma inside earth
or cooling lava on surface of earth
• Sedimentary- made of broken up bits of
rocks (called sediment) which is eventually
cemented together
• Metamorphic- deformed rock


Rock cycle
Shows the interrelationships among the
three rock types
Earth as a system: the rock cycle
• Magma

• Crystallization

• Igneous rock
• Weathering, transportation, and deposition


Rock cycle
Earth as a system: the rock cycle
• Full cycle does not always take place due to
"shortcuts" or interruptions
•
•
•
•

e.g., Sedimentary rock melts
e.g., Igneous rock is metamorphosed
e.g., Sedimentary rock is weathered
e.g., Metamorphic rock weathers


Rock cycle
Earth as a system: the rock cycle
• Sediment
• Lithification

• Sedimentary rock
• Metamorphism

• Metamorphic rock

• Melting

• Magma


The rock cycle


Magma
• Crystallization- What is it?
• Cooling magma creates Igneous rocks


Check up Quiz
• Can an igneous rock become another
igneous rock?
• How are the processes involved with the
formation of Igneous and metamorphic
rocks different?
• Is there a beginning or end to this cycle?


Igneous Rock
Igneous rock exposed at earth’s surface is
weathered, transported and deposited at a
new location as sediment


Sediment Lithification
• Sediment- What is it?

• Lithification- Sediment hardening creates
Sedimentary rocks.


Lithification


Sedimentary Rock
• As Sediment continues to be deposited and
as layers become thicker the rock becomes
deformed
• Metamorphism- Solid state changes in
sedimentary or igneous rocks.
• Metamorphism of rock creates new class of
rock called….


Metamorphic Rock
• As pressure and temperature increase, for
various reasons (Subduction, Volcanism,
Lithification), a rock may begin to melt
• Recreates Magma


Magma
• Melting occurs and the whole process starts
over.


Link:

**Rock Cycle Movie- (5 mins)**

**Rock Cycle Animation**


Igneous rocks
Form as magma cools and crystallizes
• Rocks formed inside Earth are called plutonic
or intrusive rocks
• Rocks formed on the surface
• Formed from lava (a material similar to magma, but
without gas
• Called volcanic or extrusive rocks


Igneous rocks
Crystallization of magma
• Ions are arranged into orderly patterns
• Crystal size is determined by the rate of cooling
• Slow rate forms large crystals
• Fast rate forms microscopic crystals
• Very fast rate forms glass


Magma Crystallization


Link:
Crystal Growth

• Rock Formation animation


Igneous rocks
Classification is based on the rock's texture
and mineral constituents
• Texture
• Size and arrangement of crystals
• Types
• Fine-grained – fast rate of cooling
• Coarse-grained – slow rate of cooling
• Porphyritic (two crystal sizes) – two rates of
cooling
• Glassy – very fast rate of cooling


Fine-grained igneous texture


Course-grained igneous texture


Porphyritic igneous texture


Obsidian exhibits a glassy
texture