The secondary rocks were thought to include interlayered basalts, which Werner thought formed by combustion of buried coal layers.The Scottish geologist James Hutton (1726-1797) argued that granite and basalt by solidification within the earth (as opposed to precipitating in from oceanwater).Absolute dating, on the other hand is capable of telling the exact age of an item using carbon dating and many other techniques that were not there in earlier times.
Relative dating is different from absolute dating in which specific dates are assigned to geologic events (we will discuss absolute dating techniques later).
Strata Thickness- In the late 1800s, a British geologist estimated that 75 million years has lapsed since the beginning of the Cambrian.
This estimate was based upon the maximum known thickness of strata (from Cambrian to present) divided by the average rate of sedimentation in modern environments. Joly used the salinity of ocean water to determine the age of the earth.
The quantitative approach is admirable, but Buffon's assumptions are flawed. Silicate minerals have lower heat conductivity than steels and are better insulators leading to slower cooling rates.
Second, the calculations did not incorporate the heating effects of radioactive decay.