Radioactive dating of rocks
This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks. Some do not change with time and form stable isotopes (i.e.those that form during chemical reactions without breaking down).Free 5-day trial Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.Learn about half-life and how it is used in different dating methods, such as uranium-lead dating and radiocarbon dating, in this video lesson. As we age, our hair turns gray, our skin wrinkles and our gait slows.Fossils are generally found in sedimentary rock not igneous rock.
The man's body was recovered and pieces of tissue were studied for their C content by accelerator mass spectroscopy.
So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil.
Scientists date igneous rock using elements that are slow to decay, such as uranium and potassium.
As a member, you'll also get unlimited access to over 55,000 lessons in math, English, science, history, and more.
Plus, get practice tests, quizzes, and personalized coaching to help you succeed.