Carbon 14 dating for kids
What’s more, if the whole rock is badly weathered, it will be hard to find an intact mineral grain containing radioactive isotopes.
You might have noticed that many of the oldest age dates come from a mineral called zircon.
In a way this field, called geochronology, is some of the purest detective work earth scientists do.
There are two basic approaches: relative age dating, and absolute age dating.
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?
This means that given a statistically large sample of carbon 14, we know that if we sit it in a box, go away, and come back in 5730 years, half of it will still be carbon 14, and the other half will have decayed.
Activity: Further discussion: Good overview as relates to the Grand Canyon: age dating: Use with this cross section of the Grand Canyon from the USGS’s teaching page: Canyon Have students reconstruct a simple geologic history — which are the oldest rocks shown? Are there any that you can’t tell using the Rule of Superposition?Relative age dating also means paying attention to crosscutting relationships.Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.That’s because zircon is super tough – it resists weathering. Each radioactive isotope works best for particular applications.The half-life of carbon 14, for example, is 5,730 years.