Yakima WATERS Mini Lesson

Toilet Paper Geologic Timeline

Targets and Assessment Lesson Parameters WA Science Standards Addressed: Content Area: Geology  6-8 ES3B Earth History: Thousands of layers of sedimentary rock provide evidence that allows us to determine the age of Overview: Students explore deep time by Earth's changing surface and to estimate the age of fossils reconstructing Earth’s geologic history on a roll found in the rocks. of toilet paper.  6-8 INQE- Model: Models are used to represent objects, events, systems, and processes. Models can be used to test hypotheses Grade Level: 6-8 and better understand phenomena, but they have limitations. Assessments: Suggested Time: Two 50 minute class periods  Grade worksheet Special Materials:  Grade students on group cooperation and participation  Computer access for entire class  150 meter tape  1000 sheet roll of toilet paper

Learning Outcomes: Knowledge:  Student can explain that the age of landforms are estimated by: studying the number and thickness of rock/sedimentary layers; radiocarbon and isotopic dating methods; and analysis of fossils found within rock layers to determine the age of specific events in Earth’s history.  Student recognizes that the events on the geologic timeline represent major physical and biological changes.  Student explains that the majority of the events that have been recorded occurred in the past billion years and that those events are most abundant because they have not been eroded or buried by physical changes in the environment. Skill:  Students will be able to work cooperatively in teams  Students will be able to develop a model that represents Earth’s geologic history. Students can explore a difficult concept, deep time, by placing key events on a smaller, more tangible scale (toilet paper roll).

Science Concept Background: Implementation of this activity would be best after students have had some exposure to Washington State standards:

EALR 4: Earth and Space Science. Big Idea: Earth History (ES3). Core Content: Evidence of Change Or EALR 4: Earth and Space Science. Big Idea: Earth Systems Structures and Processes (ES2). Core Content: Cycles in Earth Systems

If they have not had lessons from these subject areas the content may be too difficult to jump into. In the “Procedure” section below suggestions are made on how you can introduce geologic time and carry out the toilet paper timeline activity with minimal background information.

The concept of deep time can be a difficult concept to understand. Earth is an estimated 4.6 billion years old, a number that goes beyond the amount of time humans typically deal with (minutes, hours, days, months, years and sometimes, hundreds of years). The geologic scale has been divided into time periods that frame specific physical and biological changes that have occurred and been recorded in landforms and by fossils. Refer to the attached “GSA Geologic Time Scale” for a detailed breakdown of the timeline. Also attached is a detailed list (TP Geologic Timeline Conversions (Excel)) of major events that have occurred from 4.6 billion years ago to the present, this list is not comprehensive but may include more topics than you want to address in one lesson. The four major time divisions in the geologic time scale are eras, Cenozoic, Mesozoic, Paleozoic and Precambrian, these time segments are illustrated and described in Step #2 of the “Procedure” section.

Materials: For the teacher: attached documents to prep for and complete the lab:  Geologic Timeline Events (Word Doc.)  Geologic Timeline Worksheet (Word Doc.)  TP Geologic Timeline Conversions (Excel)

For the class:  One 1000 sheet roll of toilet paper (for the entire class)  150 meter tape (you need it to cover ~102 meters total) For student groups:  Computers (students work in pairs or groups of three)  1 Red, green, blue and black markers o 1 marker is assigned per group, for larger classes you may need 2 of each color to double the number of groups for the activity

Procedure: In addition to the attached documents the following website is an excellent resource for developing a mini lesson on geologic time and the history of Earth, or as suggested and utilized in this lesson plan, the students can explore the student tutorial found on this website: “Exploration Through Time: Understanding Geologic Time” http://www.ucmp.berkeley.edu/education/explorations/tours/geotime/index.html

Step 1: Have students begin by pairing up on a computer to run through the following student tutorial:

“Exploration Through Time: Understanding Geologic Time” http://www.ucmp.berkeley.edu/education/explorations/tours/geotime/index.html Begin by clicking on “student start”

This tutorial provides an introduction to the geologic time scale and discusses the types of evidence that are used to determine how old the earth is and the events that have occurred throughout geologic history. Allow approximately 20 minutes to get through the program.

Step 2: After the tutorial have the students return to their seats to discuss what they learned from the tutorial. A couple of questions that may be helpful in getting a discussion started may be: How old is the age of the earth? What lines of evidence do geologists use to determine the age of the earth? What are some of the different types of dating techniques? Then segue into a brief lesson to prepare them for the toilet paper timeline. On the board draw a timeline that includes the key time periods that are emphasized in the activity. Each time period will contain time- correlated geologic events that are color coded by the eras listed below. Present to 65 MYA (millions of years ago) = Cenozoic (blue) 65-250 MYA = Mesozoic (green) 250-540 MYA = Paleozoic (red) 540-4600 MYA = Precambrian (black)

Cenozoic Mesozoic Paleozoic Precambrian

*This example is not to scale

Step 3: Assign students to groups. For larger class sizes I recommend splitting the events from each era into 2 groups, that way there are a total of 8 groups of ~4 or 5 students.

Note: The slips that contain each event are found in the Geologic Timeline Events Word Doc. The slips should be cut and separated into their respective era-color-coded group. An explanation and description of the event slips is provided within the document.

Each group will be responsible for placing the events they are given in the appropriate time place along the toilet paper timeline. Explain that they will tape the event slip onto the side of the toilet paper roll and using the appropriate era group color draw a line across the roll, marking the time in which the event occurred. For example, if a group had the event “dinosaur extinction” they would use the color blue and label the toilet paper roll at 143.57 cm (from the beginning/present day end of the roll) as 65 MYA.

Step 4: Take the class to the location where the activity will be held. Have the students unroll the toilet paper making sure that it stays in one piece. At the toilet paper is being unrolled the tape measure should also be laid out next to it. The tape measure will help guide the students through the timeline. Once the roll and tape are in place students can break into their groups and begin placing the event slips on the roll. The photo below gives you an idea of how the toilet paper timeline will look.

Once they have finished, bring the group together and walk through geologic time together, discussing the events that have occurred as a group and allowing time for any questions and/or observations that the class may have. The attached timeline worksheet can be handed out after the activity as homework or be completed in class to turn in for a grade.

Present Day

65 MYA

250 MYA

55 meters to the end of the toilet paper roll (4600 MYA)

Extension(s): I followed this lesson up by having the classes construct a regional geologic timeline that will be built upon throughout the year. The regional timeline enables the class to learn about events that shaped the local landscape. This follow-up also provided an opportunity for the students to construct a shorter geologic timeline on a smaller scale.

Teaching Tips: If you do not have access to computers you will need to develop a mini lesson introducing the age of the earth and discuss the lines of evidence that scientists have used to determine the timing of specific events in geologic history. The following webpage is a great resource that can help you develop a lesson: University of California Museum of Paleontology, K-12 Teacher Resources (Includes “Explorations Through Time”): http://www.ucmp.berkeley.edu/education/teachers.php

Make sure that you have a long enough space to unroll the entire roll of toilet paper (~335 ft). On a dry day, outside will work but remember that the toilet paper is fragile and tears easily so you will need a relatively smooth surface to lay it down.

2-ply toilet paper is also recommended for durability, if you kind find 1000 sheet 2-ply.

Author: Tabitha Trosper, Yakima WATERS Project, CWU, Fall 2010