Hello,
Sedimentary rock cannot be dating using radiometric dating methods. Although some can be dated using this method, but most cannot.
If one ever studied Earth Science, they should know radioactive elements occur naturally in igneous rock; thus igneous rock can be dated using radiometric dating. One should additionally have the knowledge of understanding that half-life can [only] be applied to rocks with radioactive elements.
Because igneous rocks contain natural occurrences of radioactive elements they can be dated using the half-life of the substance. Radioactive dating is well used on igneous rock. In contrary, radioactive dating is not well worked on sedimentary rock; this is because most sedimentary rocks do not contain radioactive elements and therefore can not be dated using radiometric dating methods.
Scientists date sedimentary rocks by using the dates of igneous intrusions (rocks formed in magma) and extrusions (rocks formed outside lava) near the sedimentary rock layers to get an absolute date.
Faith xoxo