However, on the whole, he thought that these sources were not adequate to account for anything more than a small faction of the heat lost by the Earth.Based on these assumptions he at first suggested an age of the Earth of between 100 Ma and 500 Ma.In his study Rutherford measured the U and He (He is an intermediate decay product of U) contents of uranium-bearing minerals to calculate an age.One year later Boltwood (1907) developed the chemical U-Pb method.By combining Von Weizsackerâ€™s argon abundance arguments with Kohlhorsterâ€™s observation that potassium emitted gamma-radiation, Bramley (1937) presented strong evidence that potassium underwent dual decay.
This led to the discovery of There is, of course, one radiometric dating method that appears to overcome the vital “zero date problem”.
“The fascinating impressiveness of rigorous mathematical analyses, with its atmosphere of precision and elegance, should not blind us to the defects of the premises that condition the whole process.
There is perhaps no beguilement more insidious and dangerous than an elaborate and elegant mathematical process built upon unfortified premises.” – Chamberlain 1899b:224 Following the discovery of radioactivity by Becquerel (1896), the possibility of using this phenomenon as a means for determining the age of uranium-bearing minerals was demonstrated by Rutherford (1906).
However, before this time some very popular indirect methods were available.
For example, Lord Kelvin had estimated the ages of both the Earth and the Sun based on cooling rates.