Geological Time Scale

Geologic Time Scale

Introduction
Understanding geologic time is critical to relating events in Earth’s history to those of today. Scientists use several forms of the geologic time scale to classify the age of objects and to become familiar with other events occurring simultaneously. In this lesson you will:
· Examine how the geologic time scale summarizes Earth's history
· Analyze physical and biological changes that have occurred over time
· Identify major events that occurred in geologic time
· Observe the model of the geologic time scale
Procedure
1. Below you have been provided with a scaled chart to show the geological time scale. Each ___ represents 1 centimeter. The beginning of Earth was 4.6 billion years ago and is represented as 4.6 meters, therefore each centimeter represents 10 million years. For the sake of inputting data some rows will be larger than others, however each 10 million years is correctly represented in the Eon column.
2. You will need to complete the scale by choosing the appropriate drop down field as well as recording significant biological and geological events. Because the scale has been provided for you, the majority of your grade will be based on the information you gather for events.
3. Read the Observations and keep and pay close attention while gathering data.
4. After you have completed the scale answer the Reflection Questions.
Observations
· Examine how the geologic time scale summarizes Earth's history
· Pay close attention to last 540 million years
· During the last 540 million years observe how quickly complex life evolved
· Notice the amount of time humans have been in existence compared to the creation of Earth.
Reflection Questions (10 points)
Do not answer until you have completed scale below
1. Explain how the scale provided is designed to show the Earth’s history and show the calculations:
2. Based on the scale, how much longer (in centimeters) was the time before the Phanerozoic Eon compared to the rest of the scale?
3. How many “years” separate the dinosaurs from humans on Earth?
4. Were you surprised by the length of the time scale when you saw it on a continuous piece of paper? Why or why not? Explain your answer as it relates to the scope of Earth’s geologic past.

Geological Time Scale
(40 points)

|ERA|PERIOD|BIOLOGICAL AND GEOLOGICAL EVENTS|
|(Present to 65 mya)|(Present to 1.8 mya)| |
|NOT TO SCALEREPRESENTS 6.5 CENTIMETERS|(1.8 to 65 mya)| |