Relative dating of fossils activity updating flat text database files in perl
I also like this simple exercise, a spin-off from an activity described on the USGS site above.
Take students on a neighborhood walk and see what you can observe about age dates around you.
The narrower a range of time that an animal lived, the better it is as an index of a specific time.
Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This rule is common sense, but it serves as a powerful reference point.
Geologists draw on it and other basic principles ( to determine the relative ages of rocks or features such as faults.
For example, which is older, the bricks in a building or the building itself?
Are there repairs or cracks in the sidewalk that came after the sidewalk was built?