what methods are used to date fossils and rocks
Fossils themselves, and the sedimentary rocks they are found in, are very difficult to date directly. Instead, other methods are used to work out a fossilâs age. These include radiometric dating of volcanic layers above or below the fossils or by comparisons to similar rocks and fossils of known ages.here are two main methods to date a fossil. These are: 1  absolute dating methods that tell us the actual age (in years) of an object. 2  There are many absolute dating methods. 3  Nearly all of these methods make use of radioactive elements that occur naturally in various types of minerals and organic matter.