Rock Classification Answer Key Template (Page 3 of 3) in pdf

Rock Classification Answer Key Template Page 3

Get the Gizmo ready:

Activity B:

• Click Reset.

Rock locations

• Select the LOCATION tab.

Introduction: Igneous rocks that form under Earth’s surface are called intrusive. Intrusive

igneous rocks usually have large mineral grains because they form from magma that cools

slowly. Igneous rocks that form above ground are extrusive. Extrusive igneous rocks have

small mineral grains or no grains at all because they form from lava that cools quickly.

Question: Where do different kinds of rocks form?

1. Label: Review how the different

types of rock form. On the

diagram at right, label where

you would expect the following

types of rock to form:

• extrusive igneous rocks

• intrusive igneous rocks

• metamorphic rocks

• sedimentary rocks

Select Show classification

names to check your labels.

Correct any rock locations that

you labeled incorrectly.

2. Classify: Drag the rocks from the SIMULATION pane to the correct positions on the

LOCATION tab. Click on Status to check your placements. When you are done, click COPY

SCREEN to take a screenshot, and then paste the image into your blank document.

Which rocks did you classify as extrusive and intrusive igneous rocks?

Extrusive:

Intrusive:

Basalt

Gabbro

Pumice

Granite

3. Analyze: What features did you use to classify igneous rocks as extrusive or intrusive?

Sample answer: I used mineral crystal size and the presence or absence of air holes.

4. Draw conclusions: Extrusive igneous rocks often have air pockets, but intrusive igneous

rocks never do. Why do you think is this the case?

The pressure under Earth’s surface is great enough that it would crush any forming air

holes. [The gases in magma remain dissolved under high pressure.]

Rock Classification Answer Key Template Page 3