Fossils can be dated using absolute and relative dating methods.
The fossil record is a biological roadmap for the evolution of life on Earth. By using this constantly updated tool, along with methods of absolute and relative fossil dating that are cross checked by different scientists and study groups, fossil dating can be considered accurate.
Absolute Dating
Absolute dating can tell scientists the age of a fossil. Most absolute methods use ways of measuring naturally occurring radioactivity found in organic matter and minerals.
Fission Track
One method of absolute dating includes fission track, which measures uranium content and counts fission tracks. Fission tracks are created by splitting atoms during uranium decay. The older the object, the more decay and the greater number of fission tracks left behind.
Argon Dating
Two forms of argon dating are used in absolute dating. Potassium-argon dating measures the amount of argon and radioactive potassium inside volcanic rock and ash. Fossils found between eruptions can be dated by dating the surrounding volcanic layers. A newer method, argon-argon dating is considered more accurate and only requires one sample of material rather than two.
Relative Dating
Relative dating methods are used to determine which of two objects is older than the other, or to figure out the chronological timeline of found fossils. These methods come in handy while comparing finds at a specific site or to make a comparison between two or more sites.
Chemical Analysis
Sometimes bones found at the same site can be compared by analyzing the chemicals found inside them. Fluorine and uranium are good indicators of age because the older a bone is the more is absorbed. Calculating nitrogen content within a fossil is another method which can be used when factors such as moisture, temperature, bacteria and chemicals are considered.
Stratigraphy
If fossils are found in sedimentary rock, scientists can use stratigraphy as a means of relative dating. If there are two or more fossils found, the youngest fossil will be the one closest to the surface. Sometimes scientists already know what type of fossils are found in a particular rock layer and can use this information as a comparison.
Tags: absolute dating, absolute relative, dating considered, dating methods, fission tracks, fossils found
