(uncountable) A method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock. relative-adjective. WORDS NEAR relative-dating IN THE DICTIONARY. Relative dating utilizes six fundamental principles to determine the relative age of a formation or event. The first principle is the Principle of Superposition which. Ma) Tapeats sandstone deposited on Ga. Vishnu schist). What is the relative age of granite? When did tilting take place? Reading the rock record.