Download Rocks Rock

Rocks Rock!
What is a rock?
• Any solid mass of
minerals that occur
naturally
The Rock Cycle
• Interactions among Earth’s water, air, &
land cause rocks to change from one type
to another.
Major Types of Rocks
• Classified by their
chemical composition
& texture
• Igneous Rocks
• Sedimentary Rocks
• Metamorphic Rocks
Igneous Rock
• Forms when magma
cools and hardens
• Can occur beneath
the surface or as a
result of volcanic
eruptions
Igneous Composition
• Minerals:
– Quartz
– Feldspar
– Biotite Mica
• Granitic
• Andesitic
• Basaltic
Igneous Texture
• Coarse-Grained
– SLOW COOLING
– LARGE crystals
• Fine-Grained
– RAPID COOLING
– SMALL crystals
• Glassy
– Cools so fast no crystals can form
• Porphyritic
– Crystals do not cool at same rate
– Large crystals surrounded by small
crystals
Sedimentary Rock
• Exposed igneous or metamorphic rocks
undergoes weathering
– This means the rock is physically and chemically
broken down (by water, air, & living things) into
sediments
– Clastic Sedimentary Rock = physically broken
– Chemical Sedimentary Rock = chemically broken
• Sediments are compacted and cemented
together to form sedimentary rock
Clastic Sedimentary Rocks
• Grouped according to SIZE of sediments in the
rock
• Conglomerate
– Rounded, gravel-size or larger
• Breccia
– Angular sediments
• Sandstone
– Sand sized sediments
• Shale
– Very fine-grained sediments (most common type)
• Siltstone
– Fine-grained rock
What are these?
(Bio)Chemical Sedimentary Rocks
• Usually occurs when water evaporates off leaving a solid
product
• Limestone (from shells)
• Chalk
• Coquina (cemented shells)
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Rock Salt
Chert
Flint
Rock Gypsum
Limestone
Coquina
Chalk
Flint
Rock Salt
Chert
Rock Gypsum
Metamorphic Rock
• Under extreme pressure & temperature
sedimentary or igneous rock will change
into metamorphic rock
Foliated Metamorphic Rock
• Have a layered or
banded appearance
• Gneiss & schist
Non-foliated Metamorphic Rock
• Does not have a
banded texture
• Marble (calcite)
• Quartzite
• Anthracite
Magma
• Metamorphic
rock can melt to
form magma if it
is subject to
additional
pressure and
temperature
changes