How can scientists accurately date when stone tools were made, like those found at Lake Turkana in Kenya? Radiocarbon dating is widely used to date materials like charcoal from hearths and carbonate in snail shells, Dr. Kent said, but it is limited to about the last 50, years because of the short half-life of carbon For older sediments, techniques include tephrochronology involving potassium and magnetostratigraphy involving iron.
Radiocarbon helps date ancient objects—but it's not perfect
D: Carbon Dating and Estimating Fossil Age - Biology LibreTexts
By: Marshall Brain. A child mummy is found high in the Andes and the archaeologist says the child lived more than 2, years ago. How do scientists know how old an object or human remains are? What methods do they use and how do these methods work?
How to Determine the Age of a Fossil
Over time, carbon decays in predictable ways. And with the help of radiocarbon dating, researchers can use that decay as a kind of clock that allows them to peer into the past and determine absolute dates for everything from wood to food, pollen, poop, and even dead animals and humans. While plants are alive, they take in carbon through photosynthesis.
Radiometric dating allows scientists to find fossils in only the lowest and oldest layers of sediment. Radiometric dating shows the rate of decay of radioactive material present in any object. Scientists can use that data to find the absolute age of the fossil. In radiometric dating, scientists mix the carbon in a fossil with carbon from similar fossils whose age they know.