Label a diagram that depicts the
three different rock types.
3 TYPES OF ROCKS
IGENOUS
SEDIMENTARY
METAMORPHIC
IGNEOUS ROCKS
BALSALT
LAVA
OBSIDIAN
PERLITE
SEDIMENTARY
AGATE
BRECCIA
LIMESTONE
ASPHALT
BANDED IRON FORMATION
SHALE
METAMORPHIC
WHAT
IS A ROCK?
IGNEOUS
ROCK
A rock is a mixture of certain
minerals, volcanic glass, organic
matter, or other materials.
CLASSIFICATION OF ROCKS
Rocks are classified according
to the way in which they are
formed. There are three types of
rocks; igneous, sedimentary,
and metamorphic.
IGNEOUS ROCKS
Igneous rocks form when hot,
molten earth materials cool and
harden. Some form from lava.
INTRUSIVE OR EXTRUSIVE
Igneous rocks are intrusive or
extrusive depending how they are
formed. One way to further
classify these rocks is by the
magma from which they form.
FORMATION OF IGNEOUS ROCKS
FROM LAVA
An igneous rock can form from
basaltic, andesitic or granite
magma.
TYPE OF MAGMA
The type of magma that cools to
form an igneous rock is
determines important chemical
and physical properties of that
rock.
EXAMPLES OF IGNEOUS ROCKS
Granite
Obsidian
Pumice
SEDIMENTARY ROCKS
Sedimentary rocks are formed
when bits of fragments of earth
called sediments, are pressed
together.
SEDIMENTARY ROCKS
Sedimentary rocks form when bits
or fragments of earth called
sediments, are pressed or
cemented together by earth’s
processes. 75% of earth’s visual
rocks are sedimentary rocks.
LAYERS OF SEDIMENTARY ROCKS
Sedimentary rocks are usually
formed as layers. Layers are
formed when trash is
discomposed and when loses
energy and deposits sand and
other materials.
HOW DIFFERENT LAYERS ARE
FORMED
Older layers of rocks are at the
bottom from hundreds of thousands
of years ago. Younger layers of
rocks at the top are things that we
deposit yesterday and today.
CLASSICATION OF SEDIMENTARY
ROCKS
Sedimentary rocks are classified
by their composition and by the
manner in which they are formed.
Sediments come from weathered
and eroded igneous, metamorphic,
and sedimentary rocks.
EXAMPLES OF SEDIMENTARY
ROCKS
Sandstone
Silt
Clay
Sand
Coal
Gravel
Limestone (chalk)
Rock Salt
METAMORPHIC ROCKS
Metamorphic rocks are rocks that
form from exiting rocks.
They morph!!
THREE WAYS ROCKS MORPH!
Rocks change when they are
subjected to the intense heat
associated with volcanoes or with
bodies of magma.
THREE WAYS ROCKS MORPH!
Cont.
Rocks morph when they are
exposed to intense pressures
from overlying rocks and
sediments.
THREE WAYS ROCKS MORPH!
Cont.
Rocks morph when hot, mineralrich waters come into contact with
rocks.
FOLIATED METAMORPHIC ROCKS
Foliated rocks form when
mineral grains flatten and line
up in parallel layers. Two
examples are slate and gneiss.
EXAMPLES OF METAMORPHIC ROCKS
Gneiss
Marble
Slate
Schist
NONFOLIATED METAMORPHIC ROCKS
Layering does always occur in
metamorphic rocks. The minerals
grains grow and rearrange,
however they do not form layers.
The grains grow and interlockl like
a jigsaw puzzle.