Rock Types

Materials / Preparation

Hand specimens of igneous, sedimentary, and metamorphic rocks would be helpful but not necessary
Hand lenses if you are using hand specimens
Computers with Internet access
3-D glasses, red/cyan recommended as an extension (optional). Free 3-D (anaglyph) glasses are available at: http://www.teachingboxes.org/catalog.jsp?id=TBOXR-000-000-000-119
Students will use pages 16 - 18 in their Mountain Building Journals.

Grouping

Dependent upon the number of available computers

Teacher tips

As students found in Lesson 3, erosion is an important process in sculpting rock masses to form mountains. In this activity, students should learn that the properties of rocks provide information on the erodabilty of rocks and that erodability is determined by a rock’s resistance to mechanical and chemical weathering. Erosion is influenced by the environment in which the rock is found (terrain or topography, climate, vegetative cover, etc.)

For the purposes of this activity, erodability information is provided for middle school students. This information can be removed from the Mountain Building Journal page for high school students. Students will need to do additional research on-line or in a reference book to get erodability information.

If possible have students watch Mountain Building in the Desert – Part 3. This is accessible from the Mountain Building Student Web Page.

Procedure

Class discussion: In the last lesson, we looked at the composition of mountains and related that to how they erode. Today, we will actually take a look at the samples of rocks and see how they compare.
If you have hand samples, have students look at them. Otherwise, have students visit these websites to see hand specimens and get information about their formation. Note: These sites are accessible from the Mountain Building Student Web Page
After a sufficient amount of time to explore, have students describe the differences they see between the different rocks. They should notice color, texture, shape, luster, etc. They might also notice that these rocks are made up of different pieces (minerals).
a. Ask students what they learned about how these rocks formed.
b. Lead the discussion so that students understand that the differences between the rocks are related to how they were formed.
c. Remind students that geologists categorize rocks based on how they formed. Ask them what the three main types of rocks are: igneous, metamorphic, and sedimentary.
Have students fill out the Composition Data Table (pages 16-18) in their Mountain Building Journal using the three web pages from above.
Extension: If you have 3-D glasses available, students can visit 3D Geology from the Mountain Building Student Web Page and examine the photos of igneous, sedimentary, and metamorphic rock types.

Resources used

Free 3D Glasses
http://www.teachingboxes.org/catalog.jsp?id=TBOXR-000-000-000-119

Mountain Building in the Desert – Part 3
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-002-479

Rock Hounds
http://sln.fi.edu/fellows/fellow1/oct98/create/index.html

Rock and the Rock Cycle
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-009-642

The Stupid-Page-of-Rocks
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-003-103

3D Geology
http://www.teachingboxes.org/catalog.jsp?id=USGS-ED-000-000-000-145

Mountain Building Journal
http://www.teachingboxes.org/mountainBuilding/journal/MBJournal.pdf

Mountain Building Journal: Teacher's Guide
http://www.teachingboxes.org/mountainBuilding/lessons/journal/MBJournal_teacherGuide.pdf