Martin Van Buren High School

Mr. Cesaire

Earth Science

Introduction to rocks

Aim: How do we classify rocks?

Do now (5-7 minutes)• Define what is a rock. How are they formed in

the natural environment? What process can change a rock’s appearance or composition?

• HW: Read pages 28-29 Answer 18-25 due Wednesday.

• Mineral/Vocabulary quiz on Thursday• www.tinyurl.com/8msdk <~~ updated

What is a rock?

• A rock can be defined as a natural piece of the solid Earth, usually composed of one or more minerals.

• Quite simply it’s a solid form of Earth materials: Minerals, bits of broken rock, and parts of once living organisms.– An example of once living organisms turned

to rock: Coal

Origins of Rocks

Rock

MineralsEx: Quartz

GarnetPyroxene

Once Living OrganismsEx: Fossils

Plants

Bits of Small Rocks

Limestone

Limestone (CaCO3) often formed near bodies

of water. Notice the fossils incorporated into the rock.

Granite

Granite- an igneous rock that contains quartz, potassium feldspar, and biotite mica.Usually formed by cooling deep within Earth.

Rock formation

oRocks have three main methods of formation:oCooling of molten materialoCompaction and cementation oHeat and pressure

o The methods if formation is similar to the formation of minerals

Advancing lava

Lava is advancing down the road. Behind the lead edge the lava has cooled and solidified.

Types of rocks

• Based on how they are formed, rocks are categorized into three categories:

• Igneous

• Sedimentary

• Metamorphic

Basalt- Igneous Conglomerate-Sedimentary

Gneiss-Metamorphic

Let's Work Quickly!• Aim: What are the distinguishing features

of igneous rocks?

• Do Now: Define the following terms from the blue/orange text book

• Igneous Rock, mafic, felsic

HW #2 Read pages 54-57. Answer questions 1-10

Quiz next Monday based on pages 54-57

Igneous Rocks

• Igneous rocks are molten mixture of minerals and dissolved gases that have cooled and crystallized.

• Molten material beneath the Earth’s surface is called magma.

• Molten material above the Earth’s surface is called lava.

Igneous Rocks

• Igneous rocks are typically described by its texture.

• Texture refers to the minerals size, shape, and arrangement of crystals or grains in a rock.

• We will see examples of different textures in our hand specimens.

• Open to page 121 to 122 of the text book and answer the following questions in your notes:

• 1. Describe the rate (how fast) magma cools. What type of rock is formed?

• 2. Describe the texture of these rocks. Why are the crystals larger?

• 3. Describe the rate (how fast) lava cools. What type of rock is formed?

• 4. Describe the texture of these rocks. Why are the crystals smaller

Intrusive Rocks-Extrusive Rocks

• Igneous rocks that form due to slow cooling of magma are called Intrusive rocks. – Ex: Granite, Gabbro, Pegmatite

• Extrusive rocks cool rapidly above the Earth’s surface– Ex: Basalt, Rhyolite, Obsidian

Obsidian

Obsidian- lava has cooled so quickly that crystals were not able to form. Obsidian has a glassy appearance.

In class activity

• You have a particular rock in front of you. Briefly describe the rock’s size, shape, color, grain size, mass (weight).

• Aim: How do we distinguish the difference between igneous rocks?

• Do Now:

• HW: Read pages 54-57. Answer questions 1-10

• Quiz next Monday.

• Let’s watch a quick video on igneous rocks.

Basalt

Mafic or Felsic?

Texture?

Intrusive or extrusive?

Granite

Mafic or Felsic?

Texture?

Intrusive or extrusive?

Pumice

Mafic or Felsic?

Texture?

Intrusive or extrusive

Scoria

Mafic or Felsic?

Texture?

Intrusive or extrusive

Obsidian

Mafic or Felsic?

Texture?

Intrusive or extrusive

• Aim: How do we identify igneous rocks?

• Do Now: Take out a piece of loose leaf and prepare for your quiz on igneous rocks.

• HW#3 Use page 16 of your Earth Science Reference tables to fill out your crossword puzzle.

• Quiz next Monday on Sedimentary Rocks.

QUIZ #2• 1.How are igneous rocks formed? Where can

formation take place?• 2. Explain the differences between magma and lava.

How does it relate to the grain size of an igneous rock?

• 3. Define texture (for igneous rocks). Why do some igneous rocks have larger grains (crystals) than others?

• 4. Compare and contrast mafic and felsic rocks

BONUS How can we tell the difference between intrusive and extrusive rocks?

• We need to use our knowledge of igneous rock characteristics and page 6 of our reference tables to identify igneous rocks.

• Let’s watch a video on how to properly use the reference tables. Then we will identify several igneous rocks.

• Video available at www.tinyurl.com/8msdk

• www.myspace.com/mrcesaire

• Aim: How can we describe the texture between igneous rocks?

• Do Now: Open to page 30 of the green review book and answer the following questions: #19, 21, 22, 23, 24, 25. It will be collected.

• HW: Read pages 59 to 62. This will be for your quiz next Monday

• Quiz next Monday on Sedimentary Rocks./Project soon• Latest videos and notes online:

www.tinyurl.com/8msdk, www.myspace.com/mrcesaire

• Let’s watch a video the explains the different types of textures if igneous rocks.

• http://www.classzone.com/books/earth_science/terc/content/investigations/es0603/es0603page05.cfm?chapter_no=investigation

• Based on the texture and mineral composition, you have three families of igneous rocks.

• 1. Granite Family

• 2. Gabbro Family

• 3. Diorite Family

• Answer the following questions based on pages 123 to 124 of your text book.