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.

The layers of sedimentary rock, or strata, can be seen as horizontal bands of differently colored or differently structured materials exposed in this cliff.

The deeper layers are older than the layers found at the top, which aids in determining the relative age of fossils found within the strata. Such index fossils must be distinctive, globally distributed, and occupy a short time range to be useful.

Paleontology seeks to map out how life evolved across geologic time.

A substantial hurdle is the difficulty of working out fossil ages.

Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale.

Beds that preserve fossils typically lack the radioactive elements needed for radiometric dating ("radiocarbon dating" or simply "carbon dating").Favoriting this resource allows you to save it in the “My Resources” tab of your account.There, you can easily access this resource later when you’re ready to customize it or assign it to your students.Relative dating methods allow one to determine if an object is earlier than, later than, or contemporary with some other object.It does not, however, allow one to independently assign an accurate estimation of the age of an object as expressed in years.These strata are often most visible in canyons or gorges which are good sites to find and identify fossils.