Download Igneous Rocks

ROCKS
Rocks – usually made of two or more minerals
There are 3 main types of rocks:
Igneous
Sedimentary
Metamorphic
IGNEOUS ROCKS
Igneous Rocks – form when melted rock material
from inside the earth (magma) cools
2 Types of Igneous Rock:
Intrusive
Extrusive
Magma cools below
earth’s surface
cools slowly, so large
crystals usually form
Lava cools on top of
earth’s surface
cools quickly, so not
many crystals form
Examples of Igneous Rocks
Granite
Pumice
Scoria
Obsidian
SEDIMENTARY ROCKS
Sediment – pieces of broken rock, shells, grains of
minerals, etc.
Sedimentary Rock – sediment that forms into
layers because of years of pressure & compacting
Forming Sedimentary Rocks
Examples-Sedimentary Rocks
Sandstone
Limestone
Gypsum
Conglomerate
Shale
Examples-Sedimentary Rock
If sediment is carried by
water, why are these
sedimentary rocks NOT
under water…?
Thousands or millions of
years ago, this probably
WAS under water!
METAMORPHIC ROCKS
Metamorphic Rocks – extreme heat and pressure
inside the earth cause old rocks to change into new
rocks
At some point,
both igneous and
sedimentary rocks
can/will become
metamorphic rocks
Forming Metamorphic Rock
Examples – Metamorphic Rock
Gneiss
Slate
Marble
ROCK CYCLE
Rock Cycle – describes how different rocks are
related to one another and how rocks change
from one type to another
Every rock is always traveling somewhere in
the rock cycle.
A complete journey through the rock cycle
can take millions of years.
ROCK CYCLE