About This Chapter
Understanding Geologic Time - Chapter Summary
If you need to study basic geologic time concepts, you're in the right place. This series of bite-sized video lessons outlines the geologic time scale and helps you evaluate relative and radiometric dating methods. Our instructors use a straightforward and engaging teaching style, and they're available to answer any questions you may have. The chapter also includes printable lesson transcripts and interactive self-assessment quizzes. Studying these lessons can help you:
- Identify the major eons, eras, periods and epochs on the geologic time scale
- Assess numerical and relative dating methods
- Define the components of relative dating
- Explain the principles of radiometric dating
- Assess the significance of half-life in radiometric dating
- Describe fossil preservation conditions
- Understand how index fossils can indicate time
1. Geologic Time Scale: Major Eons, Eras, Periods and Epochs
The geologic time scale is an essential tool for understanding the history of Earth and the evolution of life. In this lesson, explore the principal eons, eras, periods, and epochs that help us track major events in geologic history.
2. Methods of Geological Dating: Numerical and Relative Dating
Learn how scientists determine the ages of rocks and fossils. We'll explore both relative and numerical dating on our quest to understand the process of geological dating. Along the way, we'll learn how stratigraphic succession and radioactive decay contribute to the work of paleontologists.
3. What is Relative Dating? - Law of Superposition, Principles of Original Horizontality & Cross-Cutting Relationships
Discover how geologists study the layers in sedimentary rock to establish relative age. Learn how inclusions and unconformities can tell us stories about the geologic past. We'll even visit the Grand Canyon to solve the mystery of the Great Unconformity!
4. Principles of Radiometric Dating
Radiometric dating is a method used to determine the age of rocks and other materials based on the rate of radioactive decay. Learn about three common types of radioactive decay: alpha decay, beta decay and gamma decay.
5. Radiometric Dating: Methods, Uses & the Significance of Half-Life
Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes. Learn about half-life and how it is used in different dating methods, such as uranium-lead dating and radiocarbon dating, in this video lesson.
6. Conditions of Fossil Preservation: Rapid Burial, Hard Parts & the Elements
Learn how fossils are formed and how varying conditions affect the preservation of organisms. What is the best way for a dinosaur to become fossilized? Find out here!
7. Relative Dating with Fossils: Index Fossils as Indicators of Time
You may already know how to date a fossil with a rock. But did you know that we can also date a rock with a fossil? Watch this video to find out how we use index fossils to establish the relative ages of rocks.
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Other chapters within the UExcel Earth Science: Study Guide & Test Prep course
- Basic Earth Science Concepts
- Understanding Earth's History
- The Properties of Matter
- Overview of Earth's Spheres & Internal Structure
- The Lithosphere
- Overview of Minerals & Rocks
- Igneous Rocks Basics
- Weathering, Erosion & Wasting
- Sedimentary & Metamorphic Rocks
- Geological Forms
- Water Balance
- Understanding Running Water
- Overview of Groundwater Systems
- Life Cycle of Glaciers
- Properties of Oceans
- Basics of Coastal Hazards
- The Atmosphere
- Weather and Storms
- Understanding Earthquakes
- Understanding Energy Resources
- UExcel Earth Science Flashcards