Transcript Rocks - Plattsbugh City School District

What is Earth Made of?
Rocks
Minerals
What does Earth look
like from space?
Oblate Spheroid- sphere that bulges in the center
Distance from Earth’s surface to the core varies around the world
Distance from the Poles to core is less than the distance from equator to core
Earth’s Interior
Earth’s Interior
What are rocks?
Rock- a naturally formed group of minerals bound
together; can consist of largely of one
mineral or several different minerals in
varying quantities.
Most minerals and rocks are formed deep under Earth’s surface.
Where do rocks form?
Rocks formed at Earth’s
surface come from lava.
Rocks formed under Earth’s
surface come from magma.
Three Rock Types
1. Igneous- formed by cooling and hardening of hot, molten rock
2. Sedimentary- formed by the compaction and cementation of layers
of sediments
3. Metamorphic- formed by the effects of heat and pressure on
preexisting rocks
Igneous Rocks
Felsic- large amounts of silica; generally
lighter in color
Common minerals in felsic rocks: quartz, potassium feldspar
Mafic- large amounts of iron; generally darker in color
Common minerals in mafic rocks: pyroxenes, amphiboles,
and biotite