Answer:
relative and absolute dating
Step-by-step explanation:
Two methods of dating fossil fuels are -
a) Relative Dating and b) Absolute Dating
a) Relative Dating - In this method, unknown age of fossil A is determined by comparing it with the known age of fossil B via correlation . Such " fossils B" are known as index fossils. These index fossils belong to a specific age group.
Some common example of index fossils are -
brachiopods,
trilobites, and
ammonites
b) Absolute Dating - In this method, the age of rock is determined through radiometric dating methods. Here, instead of dating the fossil itself, the rock or volcano layer above and below the fossil is dated for determining a rage of date.