The two methods are "RELATIVE DATING" and "ABSOLUTE DATING". :)
Index fossils
death
relative and absolute. relative is determining the relative order of past events, without necessarily determining their absolute age. Absolute is the process of determining an approximate computed age in archaeology and geology.
Index
Perhaps by carbon dating and by comparing with the evolution and dominance of various organisms in the geological time scale.
Determining the ages of igneous rocks helps to establish the age of the rock layer in which fossils are found. By dating the igneous rocks above and below the fossil-containing layer, scientists can narrow down the possible age range of the fossils found within that layer. This helps to provide a more accurate estimate of the fossil's age.
Index fossils, which are geographically widespread, of a quickly evolving specie, and only present in sedimentary strata of a particular geologic age, are generally reliable in setting a general time range for the age of a rock specimen.
Paleontologists age fossils primarily through relative dating and radiometric dating. Relative dating involves determining the age of a fossil based on its position in sedimentary rock layers, using the principle of superposition, where younger layers are deposited on top of older ones. Radiometric dating, on the other hand, measures the decay of radioactive isotopes within the fossils or surrounding rocks, providing a more precise numerical age. Together, these methods help build a timeline of the Earth's biological history.
Strontium-90 would not be useful for determining the age of fossils because it has a relatively short half-life of about 29 years, which means it decays too quickly to be effective for dating ancient fossils. Fossils are typically millions of years old, so isotopes with longer half-lives, like carbon-14 or uranium-238, are more suitable for dating. Additionally, strontium-90 is primarily produced from nuclear reactions and is not naturally occurring in significant amounts in geological contexts.
Relative dating is the science determining the relative order of past events, without necessarily determining their absolute age Absolute dating is the process of determining an approximate computed age in archaeology and geology.
Two ways to date fossils are relative dating, which involves determining the age of a fossil in relation to other fossils or geological layers, and absolute dating, which provides a numerical age for a fossil using techniques like radiometric dating.
Geologists look for index fossils in the sedimentary rock to help determine its age. Index fossils are of organisms that were widespread and only existed during a specific slice of geologic time. Finding an index fossil in a rock means that the rock dates to that specific slice of time.