Dating mt st helens rocks
At first, the use of “key” diagnostic fossils was used to compare different areas of the geologic column.Although there were attempts to make relative age estimates, no direct dating method was available until the twentieth century.Of course, this was a close as Kelvin ever came to publicly recanting his position.Later, after radioactivity had been proven to be a significant source of the Earth’s internal heat, he did privately admit that he might have been in error.These first â€œgeochronology studiesâ€ yielded the first â€œabsolute agesâ€ from geologic material, which seemed to indicate that parts of the Earth’s crust were hundreds of millions of years old. During this same period of time Thomson (1905), Campbell and Wood (1906) demonstrated that potassium was radioactive and emitted beta-particles.
The same is true of the basis of Kelvin’s estimate of the age of the Earth.
The solar estimate was based on the idea that the energy supply for the solar radioactive flux is gravitational contraction.
These two independent and agreeing dating methods for of the age of two primary members of the solar system formed a strong case for the correctness of his answer within the scientific community.
Of course, Kelvin formed his estimates of the age of the Sun without the knowledge of fusion as the true energy source of the Sun.
Without this knowledge, he argued that, “As for the future, we may say, with equal certainty, that inhabitants of the Earth cannot continue to enjoy the light and heat essential to their life, for many million years longer, unless sources now unknown to us are prepared in the great storehouse of creation.” This last statement was prophetic.
“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.