Question

The fossils are dated now by

• A. Stratigraphic position
• B. Amount of calcium residue
• C. Association with other animals
• D. Radio-active carbon contents

Answer 1

The correct option is D Radio-active carbon contents

Both ordinary (C-12) and radioactive carbon (C-14) is present in atmosphere which is incorporated in bodies of living organisms during their life. Decay of radioactive carbon occurs after their death. The amount of radioactive carbon present in fossils give its relative age assuming that no more radioactive carbon was incorporated since it was alive and its amount in atmosphere is constant. Since, half life of carbon is small (5600 years), this method is employed for fossils less than 50000 years old.

Therefore, the correct answer is option D.