About This Chapter
Fossils & Geologic Time - Chapter Summary
Refresh your memory concerning the important details about fossils and geologic time by going through this chapter. Our instructors have designed lessons to provide you the recap you need to understand terms, definitions, and concepts related to the theories of evolution, the history of the earth, and the work of geologists. As you make your way through the chapter, you you should be able to:
- Offer examples of the major epochs, periods, eras, and eons in the geologic time scale
- Differentiate between the theories of uniformitarianism and catastrophism
- Identify the importance of the fossil record
- Show geological dating methodologies
- Establish the principles and laws of relative dating and radiometric dating
- Determine conditions to consider for fossil preservation
- Outline how time indicators can be determined with relative dating
These chapters include text and video lessons, and these short video presentations can often be viewed in eight minutes or less. Some people enjoy watching all the video lessons at once, whereas other people only watch the lessons on topics they need to review the most. Whatever your preference, remember that you can always pause the videos, rewind them, and re-watch them as many times as you need. The timeline feature underneath each video even lets you skip around to different topics discussed within each one.
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. Theories of Geological Evolution: Catastrophism vs Uniformitarianism
Geologists haven't always agreed about the history of our planet. They have debated between catastrophism and uniformitarianism over the last few hundred years! Learn about the two main theories of geologic evolution and how scientists came to resolve the dispute.
3. Fossil Record: Definition & Examples
This lesson teaches you about the fossil record. It explains how scientists learn about Earth's distant past and highlights what fossils can tell scientists about ourselves and other organisms.
4. 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.
5. 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!
6. 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.
7. 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.
8. 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!
9. 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 Virginia SOL - Earth Science: Test Prep & Practice course
- Measurements in Earth Science
- Conducting Earth Science Experiments
- Scientific Reasoning & Logic
- Characteristics of Earth & the Solar System
- Space Exploration
- Earth's Natural Resources
- Intro to Rocks, Minerals & Soil
- Basics of Plate Tectonics
- Earth's Freshwater Resources
- Ocean & Coastal Processes
- Evolution of the Atmosphere
- Climate, Weather & Energy Transferring
- Origin & Evolution of the Universe
- Virginia SOL - Earth Science Flashcards