I saw a reference that uranium reacts strongly, and is never found pure in nature. Geologists are aware of the problem of initial concentration of daughter elements, and attempt to take it into account. This age is computed under the assumption that the parent substance say, uranium gradually decays to the daughter substance say, lead , so the higher the ratio of lead to uranium, the older the rock must be. However, neither it nor the model-age method allow for the possibility that radioactive decay might have occurred at a different rate in the past. Kennedy in Geoscience Reports, Spring 1997, No.Next
I'm guessing a little bit here. This will make the composition of the magma different at the top and bottom of the chamber. But the half-life for uranium-238 is about 4. These will be definite factors that will change relative concentrations of parent and daughter isotopes in some way, and call into question the reliability of radiometric dating. Only those are used which bear some similarity to one another.Next
However, age is not a substance that can be measured by scientific equipment. This could easily be mixed into the sample and would seriously affect the dating of that sample. It doesn't matter if these minerals are relatively lighter than others. In particular, has shown that K is strongly related to 'c'. These minerals often produce lower precision ages than and minerals traditionally used for age dating, but are more common in the geologic record. Radioactive minerals would be partially through their cycle of half lives on the very first day. These factors can change or vary with a change in certain conditions.Next
In contrast with these inaccurate dating methods, scientific facts, such as the almost total lack of moon dust, lunar soil mixing, presence of short half-life U-236 and Th-230 in moon rocks, low level of inert gases, and lunar recession, provide strong evidence that the moon is less than 10,000 years old. Geologists assert that older dates are found deeper down in the geologic column, which they take as evidence that radiometric dating is giving true ages, since it is apparent that rocks that are deeper must be older. Here are 12 factors which will be discussed in greater detail later in this chapter: 1 No contamination could have been present, although out in nature it is very much present most of the time. Historical science is concerned with trying to work out what may have happened in a one-off event in the past. Earlier, I indicated how crystals can have defects or imperfections in which small amounts of magma can be trapped. Anyway, if isochrons producing meaningless ages can be produced by mixing, and this mixing cannot be detected if three or maybe even two, with fractionation sources are involved, and if mixing frequently occurs, and if simple parent-to-daughter dating also has severe problems, as mentioned earlier, then I would conclude that the reliability of radiometric dating is open to serious question.Next
Carbon-14 is produced in the upper atmosphere when cosmic rays produce neutrons that interact with nitrogen atoms, converting them to c-14. Therefore, it seems that the first assumption must be wrong. What radiometric dating needs to do to show its reliability is to demonstrate that no such fractionation could take place. Such a large variety of igneous rocks exists that it is logical to assume an equally large variety of magmas must also exist. P2 and P3 are small, since some rocks will have little parent substance.Next
With so many unknowns I don't think so. Conclusions Radiometric dating has been demonstrated to give wrong age estimates on rocks whose age is known. More Bad News for Radiometric Dating More Bad News for Radiometric Dating Most scientists today believe that life has existed on the earth for billions of years. Similarly, annual lake sediments can be used to estimate relative age and conventional interpretation for the Green River varves suggests they have been formed over some 20 million years. Suppose that the rock is then diluted with another source which does not contain any of D, P, or N. That is a 14-billion year error in dating! This assumed the ocean was initially pure water and that it's salinity was derived from continental erosion.Next
To understand this point, we need to understand what exactly is being measured during a radiometric dating test. In spite of its notorious inaccuracy, to this day potassium-argon dating continues to be the most common method of radioactive dating of fossil-bearing rock strata. The 235U—207Pb cascade has a half-life of 704 million years and the 238U—206Pb cascade is considerably slower, with a half-life of 4. This provides a built-in cross-check to more accurately determine the age of the sample. How can something be accurate and yet wrong? Even this is problematical, unless the magma is very hot, and no external material enters. The mineral makeup of an igneous rock is ultimately determined by the chemical composition of the magma from which it crystallized. I read that zircons absorb uranium, but not much lead.
Snelling 1994 discusses numerous false ages in the U-Pb system where isochrons are also used. I also saw a statement that uranium is abundant in the crust, but never found in high concentrations. K-Ar -- half-life of K-40 is 1. But then problems also arise with the new methods, and so the search goes on. Atmospheric Helium The decay of uranium and thorium isotopes results in a net build-up of Helium-4 atoms in the atmosphere. To get an isochron with a false age, all you need is 1 too much daughter element, due to some kind of fractionation and 2 mixing of this with something else that fractionated differently.Next