Geologic Age

Modeling dough and paper cutouts in science class? Learn about how relative age dating concepts, like the Law of Superposition and cross-cutting relationships, can be used to describe the formation of sedimentary layers.

There are more than 600,000 asteroids in our solar system. Pupils analyze images of two asteroids in order to determine if they are the same age. They count craters for each asteroid and compare numbers. 

Did you know scientists can tell the age of an asteroid by looking closely at its craters? This final lesson of a six-part series focuses on two asteroids, Gaspra and Ida, in order to demonstrate the concept of dating asteroids. Scholars...

How do scientists know the history of Earth before humans—or any mammals—existed? An epic "Eons" series video explains the larger history of geologic time. It highlights the eons, eras, periods, epochs, and ages scientists use to divide...

How are the Hawaiian Islands different from other island chains? Discover the surprising geologic history of Hawaii with a video from a cool physics playlist. The narrator takes a hike with some geologists and discusses mantle plume...

Cartoon children compare the earth's age to timescales that we understand:a calendar year, the thickness of a book, the human lifespan. This smart film clip is definitely worth adding to your geologic timescale lesson! If you subscribe...

Hear experts provide evidence of Ice Age and glacial movement based on today's geological features. Various measurement tools are used to see what chemicals are found in ice and the atmosphere in order to determine the climate of the...

Students investigae using radioactive decay to determine geologic age.

Spring breakers first gathered in Wakulla Springs, Florida, over 10,000 years ago! Geologists and archaeologists work together to uncover hidden artifacts from this time period. Even 10,000 years ago, people went to Florida to warm...

Students practice dating fossils. They learn the concept of "deep time"--that earth was formed billions of years ago. They experience excellent hand-outs and virtual age tutorial links.