Oxygen isotope dating
What caused camelids to migrate to North America during the Pleistocene Epoch?These and countless other questions are the types of inquiries that drive Quaternary geology.
The main driver of the evaporation effect in most geological intervals is the amount of water that has been removed from the ocean and is sequestered in ice (see video clips below).
So, because different isotopes of the same element have different weights, they behave differently in nature.
Oxygen has three different isotopes: oxygen 16, oxygen 17 and oxygen 18.
Using the INEEL illustration above, then, one can conclude that plutonium-240 is more massive than plutonium-238; that is, plutonium-240 weighs more than plutonium-238.
This principle will become important during the discussion on oxygen-isotope dynamics. Stable isotopes are those isotopes that do not experience radioactive decay, whereas unstable isotopes are those that do experience radioactive decay.