* Radiometric dating relies on the decay of radioactive isotopes. These isotopes are typically found within minerals.

* Sedimentary rocks are formed from fragments of pre-existing rocks. This means the minerals within a sedimentary rock are not necessarily the same age as the rock itself.

* The age of a sedimentary rock reflects the age of its source material, not necessarily the time it was formed.

Exceptions:

* Some sedimentary rocks may contain volcanic ash layers. These ash layers can be dated radiometrically, providing an age for the surrounding sediment.

* Sedimentary rocks can sometimes be dated indirectly. By examining the fossils within them and comparing them to known ages of fossils in other locations, a general age estimate can be made.

Therefore, while radiometric dating can be useful in understanding the age of materials within sedimentary rocks, it doesn't directly provide the age of the rock itself in most cases.