This uses radioactive minerals that occur in rocks and fossils almost like a geological clock. Its often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in. These isotopes break down at a constant rate over time through radioactive decay.

Can sedimentary rocks be dated?

Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years. So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil.

Why is sedimentary rock hard to date?

Explanation: Radioactive elements decay at a certain constant rate and this is the basis of radiometric dating. Sedimentary rocks may have radioactive elements in them, but they have been re-worked from other rocks, so essentially, there radiometric clock has not been re-set back to zero.

What is the most accurate way to date a rock or fossil?

radiometric dating methods To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

What animal can live forever?

jellyfish Turritopsis dohrnii To date, theres only one species that has been called biologically immortal: the jellyfish Turritopsis dohrnii. These small, transparent animals hang out in oceans around the world and can turn back time by reverting to an earlier stage of their life cycle.