Epoch (geology)

High school (ages 12+)
Environment & Earth

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/epoch-geology

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the chronostratigraphic unit?Epochs are subdivisions of geological periods, representing specific intervals of time
2. What is an epoch in geology?An epoch is a chapter of Earth's history that lasts a few million years and is marked by special rocks and fossils.
3. How do scientists decide where one epoch ends and another begins?Scientists look at fossils, magnetic flips in rocks, and dates from volcanic ash to find clear changes that show a new epoch.

Chronostratigraphy: The branch of stratigraphy concerned with the age of rock strata and their relationship to time.
Biostratigraphy: The branch of paleontology that characterizes and names divisions of rock strata based on the fossil content.
Magnetostratigraphy: A method of dating rocks by using the Earth's past magnetic field reversals recorded in the rocks.
Radiometric Dating: A method of dating geological materials, such as rocks or carbon, by using the decay rates of radioactive isotopes.