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 limits of using uranium in dating the age of objects?

Uranium-series dating U-series dating can be used for dates to around 400,000 years, using laser ablation. Contamination of the sample over this time will impact the readings. If uranium or thorium has moved into or out of the sample over the ages, then the dates obtained will be questionable.

What are two limits to using uranium-238 dating?

Uranium 238 is only found in igneous or volcanic rocks. So no fossils can be dated directly using U 238. Because of the huge differences in the half lives of Carbon 14 and Uranium238 they cannot be used together. Carbon 14 can only be used to date fossils of a very recent age.

What are the limitations of uranium-238?

The more lead the rock contains, the older it is. The long half-life of uranium-238 makes it possible to date only the oldest rocks. This method is not reliable for measuring the age of rocks less than 10 million years old because so little of the uranium will have decayed within that period of time.