IGNEOUS ROCKS Friday April 27 th, 2012 Warm-up: 1. What are the three things scientists look at to classify rocks? 2. What are the three major groups of rocks? Homework: - Everything is Due today! Objective: Students will be able to analyze characteristics of igneous rocks in order to explain how igneous rocks are formed.

Classwork 1. Observe the characteristics of the two rock samples provided by your teacher. Discuss with your partner the different characteristics that you are able to observe about each rock (i.e. grain size, texture, pattern, etc.). Write your list of observed characteristics in the space below. (page 13)

Pumice Lighter of the 2 samples Dull Very porous More fragile Rough More fine grain One color

Granite Smooth side Small sample size Heavier of the 2 samples Shiny on some sides Multicolored Coarse grained Not porous Very durable

Classwork 2. Predict where each rock sample may have formed. Provide specific characteristics that you observed in order to help support your prediction. I predict that granite was formed under ground. This is because it is very tough and durable. I predict that the pumice was formed in the ocean. This is because it is lightweight and soft.

A. Lava is found at _____ and magma is found at _____. B. Magma cools ______because it is _______________. C. Igneous rocks with large crystals form from ________ whereas igneous rocks with small or no crystals form from _______. A B Earth’s surface Volcanic layers BA slowly under the ground magma lava B A Volcanic Layer

Classwork 4. Use pages from Inside Earth to gather the following information about igneous rocks. Put the information into the Igneous rocks chart. --- From what materials do igneous rocks form? ---How are igneous rocks classified? --What’s the difference between intrusive to extrusive igneous rocks? -- How does cooling rate affect the grain size of igneous

EXIT TICKET Make a general statement about how igneous rocks are formed. Use evidence from the investigation to help you write your statement.

IGNEOUS ROCKS Monday April 30 th, 2012 Warm-up: 1. If an igneous rock takes a long time to cool, will the grain size of the rock be large or small? Homework: - Will be handed out tomorrow! -QUIZ ON FRIDAY!! Objective: Students will be able to analyze characteristics of igneous rocks in order to explain how igneous rocks are formed.

Classwork 1. What is a dichotomous key? - tool used to identify things by dividing into two groups What do scientists use it for and why is it helpful to identify rocks? Dichotomous keys will be helpful in classifying the different rock samples because they allow us to identify unknown rocks based on the rock’s characteristics.

Classwork Before we use the dichotomous key to identify igneous rocks, lets review what we know about igneous rocks 2. Igneous rocks can form by ________________________________________ 3. Igneous rocks can cool _____________________________________________

Think you know enough about igneous rocks to identify them? Use what you’ve researched about igneous rocks to identify the different rock samples I’ve sent to your teacher. Good Luck!

CLASSIFYING IGNEOUS ROCKS A.Obtain the rock samples from your teacher. B.Use the dichotomous key to identify the igneous rocks based on their observable characteristics. C.Place the rocks in the appropriate space on the dichotomous key when you think you have correctly identified each rock. D.Ask your teacher to verify your identification of each rock. E.Determine if each rock was most likely formed from magma or lava. (HINT: use grain size/crystal size to help you make your decision.) F.Record your decision in Chart 1, “Classifying Igneous Rocks.” G.Identify the rocks as either intrusive or extrusive by placing an “X” in the appropriate column.

Chart 1: Classifying Igneous Rocks Rock Formed from Magma or Lava Cooled Slowly (Intrusive) Cooled Rapidly (Extrusive) SCORIA Basalt Diorite Gabbro Granite Obsidian Pumice Rhyolite

Chart 1: Classifying Igneous Rocks Rock Formed from Magma or Lava Cooled Slowly (Intrusive) Cooled Rapidly (Extrusive) ScorialavaX BasaltlavaX Diorite Gabbro GranitemagmaX ObsidianlavaX PumicelavaX Rhyolitelavax

CLASSWORK 7. Create a Venn Diagram to compare intrusive and extrusive rocks

EXIT TICKET Explain how the cooling rate of molten material affects the formation and the grain size of igneous rocks. Provide examples from the investigation to support your response. 3 – answer explains how the cooling rate affects the grain size and formation of igneous rock and is supported with an example 2 – answer explains how the cooling rate affects the grain size and formation of igneous rock; answer is not supported with an example 1 – answer explains only how the cooling rate affects the grain size OR formation of igneous rock; answer is not supported with an example