Label a diagram that depicts the three different rock types.

3 TYPES OF ROCKS

IGENOUS

SEDIMENTARY

METAMORPHIC

IGNEOUS ROCKS

LAVABALSALT

OBSIDIAN PERLITE

SEDIMENTARY

AGATE

BRECCIA

LIMESTONE

ASPHALT

BANDED IRON FORMATION

SHALE

METAMORPHIC

IGNEOUS ROCK

A rock is a mixture of certain minerals, volcanic glass, organic matter, or other materials.

WHAT IS A ROCK?

CLASSIFICATION OF ROCKS

Rocks are classified according to the way in which they areformed. 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, mineral-rich 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.