The Rock Cycle

1
The Rock Cycle

• By Andrea Santoro

2
Objectives

• How rocks are formed
• The different types of rocks
• Where you can find these rocks
• Examples of different rocks

3
What is a Rock?

• A rock is a substance formed of minerals through
  the process of the rock cycle
• The most common material on Earth

4
What is a Rock?

• There are 3 types of rocks
• Igneous, Sedimentary, and Metamorphic
• Rocks in each group differ based on how they were
  formed, size, shape, color and the arrangement of
  the mineral grains

5
Igneous Rocks

• When rocks reach high temperatures they can melt
  into magma
• Magma is located in volcanoes and under the
  earths surface
• Once magma reaches the earths surface it cools
  and crystallizes into an igneous rock

6
How to Spot an Igneous Rock

• Interlocking texture of grains
• Vesicules (holes)
• May be dark-colored and heavy
• May display two grain sizes, one larger than the
  other

7
Example of an Igneous Rock

• Granite rocks are igneous rocks which were formed
  by slowly cooling pockets of magma that were
  trapped beneath the earths surface
• Granite is used for long lasting monuments and
  for trim and decoration on buildings

8
Sedimentary Rocks

• Made up of any existing rock by forces of wind,
  rain, ice, and snow
• Forces break down or dissolve and carry away
  portions of rock
• Eventually these particles are deposited in/on
  the earth and form hard rock

9
How to Spot a Sedimentary Rock

• Grains cemented together
• The presence of fossils
• Light-colored and light weight
• May display interlocking grains but is very light
  weight

10
Example of a Sedimentary Rock

• Limestone rocks are made from the mineral calcite
• Calcite comes from the beds of evaporated seas
  and lakes as well as from sea animal shells
• Limestone is used in concrete and as a building
  stone, especially in humid areas

11
Metamorphic Rocks

• Form when existing rocks form new minerals and
  textures
• This is caused by higher heat temperatures and
  pressures but does not cause melting

12
How to Spot a Metamorphic Rock

• Interlocking texture of large grains
• Layering known as foliation
• Light and dark colors banded together in the same
  rock
• When tapped, makes a light ching sound instead
  of a hard chunk sound

13
Example of a Metamorphic Rock

• Schist rocks form from either the igneous rock
  basalt, the sedimentary rock shale, or from slate
  which is another metamorphic rock
• Through the process of tremendous heat and
  pressure (without melting) this different rock
  type is formed

14
Assignment

• You will create a database of different rocks
  within the 3 rock types
• You will choose a rock from the list passed out
  on your database worksheet If you would like
  to choose a rock not on the list, check with me
  first
• Be sure to include details such as type of rock,
  size, shape, color, uses, etc.
• Once you have completed your database worksheet,
  you will enter the information onto our Rock
  Database using Microsoft Access