Download Rock Cycle Teacher Notes

APES Rock Cycle Teacher Notes
Igneous
Rock
1
2
5
Magma
Sediment
(Sand, Silt, Clay)
2
5
2
3
4
Metamorphic
Rock
Sedimentary
Rock
4
On the diagram of the rock cycle shown above, each line represents a unique process. Figure out what is
happening in each process.
1.
Represents ____________________
2.
Represents ____________________
3.
Represents ____________________
4.
Represents ____________________
5.
Represents ____________________
The Rock Cycle
What are minerals?
What are rocks?
Where are rocks?
Mineral: Any naturally occurring inorganic
crystalline solid with a definite chemical composition
Rocks:
 Make up the crust of the earth (the part of
the earth we live on)
 Form mountains and the ocean bottom
(exist everywhere, but often buried under
soil)
 Made up of single mineral or combination
of minerals
Types of Rocks
There are three main types of rocks
Igneous
Igneous: Formed from magma (molten rock) has
cooled underground or cooled after a volcano
erupts
-quicker cooling leads to smaller crystals
Sedimentary
Sedimentary: Formed from particles of other
rocks (called sediment) that are worn off other
rocks
-the sediment get turned into rock by being
buried and compacted by weight of rocks or by
being cemented together by materials that have
been dissolved in water
Metamorphic
Metamorphic: rocks formed when other rocks are
exposed to great heat AND/OR pressure
-pressure and heat can come from being buried
deep in the earth or from proximity to magma
ROCK CYCLE:
-Rocks do not last forever
What is the rock
cycle?
 Rocks on the surface are worn down by wind
and weather
 Rocks buried deep underground are subjected
to heat and pressure and changed
 Rocks REALLY deep underground melt and
turn back into magma
 ALL THESE PROCESSES RECYCLE ROCKS
and change them from one type to another
This is the ROCK CYCLE
Igneous rocks are classified by TEXTURE and by MINERAL COMPOSITION
Texture (2 main types):
1. EXTRUSIVE (VOLCANIC): Cooled at the surface
--Quick cooling leads to small crystals
--Extrusive rocks also include glassy and frothy textures, formed when
lava is ejected into the air and
quickly cooled
2. INTRUSIVE (PLUTONIC): Cooled underground
Slow cooling leads to Large Crystals
Mineral Composition (2 main types):
A. FELSIC: Light-colored; less dense rocks like granite
-Composed of light colored minerals (quartz, feldspar)
B. MAFIC: Dark colored and denser rocks like basalt
-Composed of darker minerals
Sedimentary rocks are classified based on the materials that compose them.
There are two main characteristics:
1) PROCESS OF SEDIMENT FORMATION:
a. Chemical: Formed from dissolved substances that come out
of water that has evaporated (e.g. Halite-Rock salt)
-Also referred to as EVAPORITES
b. Clastic/Detrital: Formed from broken bits (sediment) of other
rock (e.g. Sandstone, Shale, Siltstone)
c. Organic: Formed from living organisms—water-dwelling organisms
formed sediment as part of their life (coral, clams, etc.) or from other
living organisms (e.g. coal)
2) PARTICLE SIZE (specifically for the clastic sedimentary rocks)
Sediment is classified into gravel, sand, silt, and mud based on particle size
 Metamorphic rocks are classified based on two things:
1) The degree of metamorphism (how much heat and pressure)—Generally, the
LARGER the crystals (COARSER grain), the MORE heat and/or pressure the
rock has been exposed to
Shale
(sed. rock)
Slate
Low heat
and pressure
Phyllite
Schist
High heat
and pressure
Gneiss
2) Foliation vs. Non-foliation
FOLIATION: Describes a metamorphic rock with minerals/crystals
arranged in parallel bands
NON-FOLIATION: Describes a metamorphic rock with
minerals/crystals oriented randomly (e.g. Marble, Quartzite)