Summary:
- Carbon-14 dating is very useful for ruins that contain wood.
- Carbon-14 is useful for relatively young, carbon-based materials.
- Other longer-lived isotopes are good for older rocks and minerals.
- Different isotope pairs are useful for certain materials of certain ages.
- It is not useful for determining the age of sedimentary rocks.
- For this, geologists date a nearby igneous rock.
- Then they use relative dating techniques to figure out the age.
- They may not get it exactly, but there will be some idea.