Which of the following is the relatively most accurate method for dating of fossils?
- Radio-carbon method
- Uranium-lead method
- Potassium–argon method
- Electron-spin resonance method
Answer
(4) Electron-spin resonance method
Solution
As per NCERT, the age of fossils is determined by the radioactive dating method.
⇒ Radio-carbon dating works only up to about 50,000 years; uranium–lead and potassium–argon methods date the rocks around the fossil, not the fossil itself, and have large error ranges.
⇒ Electron-spin resonance (ESR) measures the electrons trapped in the crystal lattice of the fossil's own tooth enamel / bone, so it dates the fossil directly over a wide range with relatively small error.
∴ ESR is relatively the most accurate method among those given.
Answer: (4)