The Geologic Time Scale shows the names of the eons, eras, periods, epochs, and ages along with their corresponding dates.

This enhanced version also includes illustrations and information for significant events that have occurred during Earth's long history. Illustrations by Dennis Tasa provide an artistic impression of how Earth may have appeared and how life may have evolved over time.

This app provides a quick reference for students, educators, professional geologists, or anyone interested in geology.

No internet connection required after download. Ideal for field use. Just touch the button in the toolbar to display the names and dates of the ages. Touch the info icons to see the illustrations. For each illustration, touch the "more info" button to read about life on Earth at that time.

Correlates with the Next Generation Science Standards for Earth Science:
ESS1.C: The History of Planet Earth
ESS2.E: Biogeology

What’s New

Version 2.2

updated ages and dates to the International Commission on Stratigraphy version 2018/08; now handles the notch correctly; other minor changes and improvements

Ratings and Reviews

5.0 out of 5
3 Ratings

3 Ratings

Snickshift ,


I love crib sheets and this one is terrific. It clearly maps out the time scale of the history of the planet. It gives the names and lengths of its periods and a brief description of why they begin and end when they do. Whether you are reading about the evolution of whales, trilobites, stromatolites or dinosaurs it give a quick and easy perspective of when your subject lived.
It is better than a book because it is always in your pocket.

Pompey Murphy ,

Great App and Great Graphics

This app is reminiscent of a wonderful and highly informative poster “A Correlated History of the Earth” put together a few years back by Dr. Dennis & Karen Tasa and colleagues. I do wish Dan Pikenton could bring that entire presentation to an app; but, I suppose that’s asking a lot. Still, I for one think it would be an excellent educational contribution and would be quite willing to pay the poster’s price.

Mike VV. ,

Great app!

I have only come to appreciate geology in the past couple years. I find fascinating the processes God created to continually grow/develop the landscape of our planet!
I wish I had more time toward more.

Thanks to this app I am learning each if the ages, Life during each age, etc. this is very insightful and easy-to-use.

THANK YOU, TASA, for creating geotimescale!


Danny Pilkenton
205.8 MB

Requires iOS 10.3 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© Dennis Tasa


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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