Original: The oldest continental crustal rocks on Earth have ages in the range from about 3.7 to 4.28 billion years P. J. Patchett and S. D. Samson , 2003 , Ages and Growth ot the Continental Crust from Radiogenic Isotopes .
Simplified: J. Patchett and S. D. Samson , 2003 , Ages and Growth ot the Continental Crust from Radiogenic Isotopes .