Dating the Earth

Front

What are index fossils?

Back

Index fossils are fossils of organisms that were widely distributed but only lived during a short period of time, used to identify and date the strata in which they are found.

Tags

NGSS.MS-ESS1-4

Front

List the layers of rock from oldest to youngest: E, B, C, D, A. What does this order represent?

Back

This order represents the relative ages of the rock layers, with 'E' being the oldest and 'A' being the youngest.

Tags

NGSS.MS-ESS1-4

Front

Which letter identifies the ice layer that was most recently formed?

Back

The letter 'A' identifies the ice layer that was most recently formed.

Front

If the half-life of a radioactive group of atoms is 100 years, how old is the rock if there have been two half-lives?

Back

The rock is 200 years old.

Tags

NGSS.HS-PS1-8

Front

What does the Law of Superposition state?

Back

The Law of Superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Tags

NGSS.MS-ESS1-4

Front

What is the significance of half-life in dating rocks?

Back

Half-life is the time required for half of the radioactive atoms in a sample to decay, which helps scientists determine the age of rocks and fossils.

Tags

NGSS.HS-PS1-8

Front

How do scientists use index fossils in geology?

Back

Scientists use index fossils to correlate the age of rock layers across different geographic locations.

Front

What is relative dating in geology?

Back

Relative dating is the method of determining the age of rocks and fossils in relation to one another, without determining their exact age.

Tags

NGSS.MS-ESS1-4

Front

What is absolute dating?

Back

Absolute dating is the process of determining the exact age of a rock or fossil through methods such as radiometric dating.

Front

What is the principle of original horizontality?

Back

The principle of original horizontality states that layers of sediment are originally deposited horizontally under the action of gravity.

Tags

NGSS.MS-ESS1-4