Radiometric dating is a very useful tool, but it does have limits: The material being dated must have measurable amounts of the parent and/or the daughter isotopes. Radiometric dating can be done on only some materials. It is not useful for determining the age of sedimentary rocks.
What are limitations of radiocarbon dating?
The method has limitations: Samples can be contaminated by other carbon-containing materials, like the soil that surrounds some bones or labels that contain animal-based glue. Inorganic materials cant be dated using radiocarbon analysis, and the method can be prohibitively expensive.
What are the benefits of using uranium 238?
Radioisotope Brief: Uranium Depleted uranium (uranium containing mostly U-238) can be used for radiation shielding or as projectiles in armor-piercing weapons. Where does it come from? U-235 and U-238 occur naturally in nearly all rock, soil, and water. U-238 is the most abundant form in the environment.