The following is a unit on geologic time and fossils.These lessons will provide information on how scientists use the earth to determine the history of geologic events, as well as how they can make predictions about future events.
Rocks and fossils provide a timeline for the Earth.
*What can you tell from undisturbed rock layers?
*How can fossils help scientists determine the ages of rock layers?
*What role do radioactive elements play in determining absolute age?
Students will be able to:
*Draw conclusions about the earth using the relative age of rock layers.
*Describe what role index fossils have in determining the ages of rock layers.
*Explain how absolute ages of rocks are determined.
*Model rock layers in an activity to determine an object's relative age.
Create a representation of Earth's sedimentary rock layers.Develop an explanation of the role of index fossils in determining the relative age of rock layers.Explain how to determine the absolute age of rocks.Draw conclusions based on what Earth's layers reveal about its past.
Representation of Earth's sedimentary rock layers can be made in the following mediums:
*3-D Model of Clay, Styrofoam, Paper Mache, etc.
Explanation may take the form of your choice. Options may include any of the following: *videocast
a. Students will complete a sorting activity with syllable cards and later with fossil cards.
b. Ask directed questions looking for patterns or connections between the cards representing rock layers.
c.Final product should be a vertical row of cards with the top card representing the youngest fossils of this rock sequence and the card at the bottom of the stack representing the oldest fossils.
d.Students will repeat the activity again using the fossil cards.
*Introduce the "Relative and Absolute Age" investigation (Textbook Resource)
This is a very brief exploration of sorting newspapers as a representation of rock layers.
Possible leading questions:
1. What properties of the papers did you use to order them?
2. If the ordered newspapers represented a section of layered rock, what could you tell me about the top layer and the bottom layer?(Each layer gives us information about a specific time period.The top layer is younger than the bottom layer. The layers reveal information about the climate changes, plant life and animals that lived there.)
1. If a pencil is placed between two of the newspaper layers, what might this represent?
2. If the newspapers represent layers of rock, what can we determine about the age of the pencil that was placed in the stack?(The pencil represents an index fossil.We can determine its relative age because it is only found in a specific layer.)
Bring students together to discuss and determine the differences between absolute and relative age.
Check for Understanding
Clicker Review (whole group)
Based on Clicker Review results, students who scored 80% or lower will remain in the classroom for remediation.
Students that scored 80% or higher will participate in an extension lab.
1. Teacher will meet with struggling students for clarification and to develop a real-world example to help distinguish between absolute and relative age.
1.Students that scored above 80% on their summary, will participate in an extension activity on Classzone.com to gain a deeper understanding of the Earth's Geologic History.
Students will share their rock layer models, provide explanation of index fossils, how to determine relative age of rock layers, how to determine absolute age of rocks, and how this information reveals the Earth's past.