Exploring Relative and Absolute Dating of Rocks

This video tutorial for grade 11 students covers the methods used to determine the age of rocks, focusing on relative and absolute dating. It explains how these methods help geologists in subdividing geologic time. The video discusses the principles of relative dating, such as the law of superposition, cross-cutting relationships, and inclusions. It also covers absolute dating techniques, including radiometric dating and the use of isotopes like carbon-14 and uranium-238. The tutorial concludes with how these methods contribute to understanding Earth's history and the geologic time scale.

What are the two main methods used to determine the age of rocks?

• Relative dating and absolute dating

• Radiometric dating and carbon dating

• Geologic sequencing and fossil analysis

• Stratification and superposition

Tags

NGSS.HS-ESS1-5

Which principle states that each layer of sediments is piled on top of another, making the top layer the youngest?

• Law of Original Horizontality

• Law of Cross-Cutting Relationships

• Law of Inclusion

• Law of Superposition

What is the term for a break in the Earth's crust that is always younger than the stratified rock it cuts through?

• Intrusion

• Fault

• Inclusion

• Extrusion

Which law states that rocks mixed up in the formation of sediments are always older than the layer of sediments they are embedded in?

• Law of Cross-Cutting Relationships

• Law of Original Horizontality

• Law of Inclusion

• Law of Superposition

What is the most common way of determining the absolute age of rocks?

• Geologic sequencing

• Radiometric dating

• Fossil analysis

• Stratification

Which radioactive isotope is commonly used to date the age of fossils?

• Carbon-14

• Lead-206

• Potassium-40

• Uranium-238

What is the term for the period of time it takes for a substance undergoing decay to decrease by half?

• Isotope reduction

• Radioactive period

• Half-life

• Decay rate

Tags

NGSS.HS-PS1-8

Why do geologists use both relative and absolute dating methods?

• To measure the density of rocks

• To identify the type of fossils present

• To determine the chemical composition of rocks

• To compare and verify the age of rocks

What did scientists use in the 1700s and 1800s to order rock layers from oldest to youngest?

• Absolute dating

• Radiometric dating

• Relative dating

• Carbon dating

Which period is known for the presence of many dinosaurs?

• Cretaceous

• Triassic

• Permian

• Jurassic