The least important method of determining the age of precambrian rocks is

C14 is least important for determining the age of precambrian rocks. Precambrian rocks are older than 550 million years and half life of C14 is around 5700 years. After 550 million...

Carbon 14 isotopes has half-life less than 6000year so it will all be lost by radioactively. Precambrian rocks are very old like 2500 my so we can't have carbon to date that