How does absolute dating work
Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation.
Index fossils are fossils that are known to only occur within a very specific age range.
Potassium-40 on the other hand has a half like of 1.25 billion years and is common in rocks and minerals.
This makes it ideal for dating much older rocks and fossils.
So, often layers of volcanic rocks above and below the layers containing fossils can be dated to provide a date range for the fossil containing rocks.
The atoms in some chemical elements have different forms, called isotopes.
The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.
Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods.
Then after another 5,000 years half of the remaining parent isotope will have decayed.
While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils.
Radiometric dating (often called radioactive dating) is a technique used to date materials such as rocks or carbon, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself, and can be used to date a wide range of natural and man-made materials.Carbon-14, the radioactive isotope of carbon used in carbon dating has a half-life of 5730 years, so it decays too fast.