Rocks All Over This Place

Author: Kirstin Bittel

Time: / 1 Period
Preparation Time: / 10-15 minutes
Materials: / A variety of rocks belonging to each rock type: 10-15rocks closely divided among the different types (igneous, metamorphic, and sedimentary)
Hand Lenses or Jewelers Loops

AbstractStudents will observe, describe and classify a variety of rocks based upon their physical appearance.

Purpose – To engage students in the variety of rocks that exist on Earth and how different rock types are related to the Earth’s geochemical cycles.

Objectives

Students will be able to:

  1. Identify a variety of physical characteristicsof rocks and use them to classify rocks.

National Science Education Standard:

CONTENT STANDARD D – Earth and Space Science

GEOCHEMICAL CYCLES
  • The earth is a system containing essentially a fixed amount of each stable chemical atom or element. Each element can exist in several different chemical reservoirs. Each element on earth moves among reservoirs in the solid earth, oceans, atmosphere, and organisms as part of geochemical cycles.
  • Movement of matter between reservoirs is driven by the earth's internal and external sources of energy. These movements are often accompanied by a change in the physical and chemical properties of the matter. Carbon, for example, occurs in carbonate rocks such as limestone, in the atmosphere as carbon dioxide gas, in water as dissolved carbon dioxide, and in all organisms as complex molecules that control the chemistry of life.
THE ORIGIN AND EVOLUTION OF THE EARTH SYSTEM
  • Interactions among the solid earth, the oceans, the atmosphere, and organisms have resulted in the ongoing evolution of the earth system. We can observe some changes such as earthquakes and volcanic eruptions on a human time scale, but many processes such as mountain building and plate movements take place over hundreds of millions of years.

Teacher Background

Geologists divide rocks into three main categories based upon the way in which they were formed. Igneous rocks are solidified from magma (this includes the lava that has left a volcano). Metamorphic rocks are formed from intense heat and pressure under the Earth’s surface. Sedimentary rocks are made when rocks erode, are deposited, and cemented together over time.

For more details see

Related and Resource Websites

Volcano World’s Rock and Mineral Slide Show

Activity

  1. Ask students to share what they know about rocks in general. Record student ideas.
  2. When students have exhausted their knowledge point out that rocks can be classified and that geologists do group them.
  3. Tell them that back at their laboratory tables there are a variety of rocks belonging to the different groups. Their task is to carefully observe the rocks and group them according to their physical properties. Inform students they will be sharing their groupings with the class at the end of the period so they should be prepared to present their findings and justifications.
  4. Allow students time to sort the rocks. As you walk around observing and questioning groups, make sure that all the rocks are divided into groups (Do not be discouraged if they cannot remember the three rock types and their characteristics;some will and some won’t.)
  5. Towards the end of the period, stop the class and have one volunteer from each group explain their groups and the properties of each. Record the groups’ characteristics on the board to facilitate discussion at the end of class.
  6. Call students back to the front of the room and discuss the three rock classifications that geologists use. Tell them their challenge over the week is to determine how the rock formations are tied to plate tectonics.

Embedded Assessment

Do students have three distinct groups? Do all the rocks in the groups have the same physical properties?

Homework

Write a 2-3 sentence conclusion in your science notebook.