Evolution and carbon 14 dating
Radioactive elements are common only in rocks with a volcanic origin, so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers.
Carbon dating uses the decay of carbon-14 to estimate the age of organic materials, such as wood and leather.
There are several different methods for estimating the ages of fossils, including: Paleontologists rely on stratigraphy to date fossils.
Stratigraphy is the science of understanding the strata, or layers, that form the sedimentary record.
Strata are differentiated from each other by their different colors or compositions and are exposed in cliffs, quarries, and river banks.
These rocks normally form relatively horizontal, parallel layers, with younger layers forming on top.
But new research shows that commonly accepted radiocarbon dating standards can miss the mark -- calling into question historical timelines.
Half-life of Carbon-14: Radiometric 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 half-life of carbon-14 is 5,730 years, so carbon dating is only relevant for dating fossils less than 60,000 years old.
If a fossil is found between two layers of rock whose ages are known, the fossil’s age is thought to be between those two known ages.
Because rock sequences are not continuous, but may be broken up by faults or periods of erosion, it is difficult to match up rock beds that are not directly adjacent.