Uranium decay dating


These basalts yield ages of up to 1 million years based on the amounts of potassium and argon isotopes in the rocks.But when we date the rocks using the rubidium and strontium isotopes, we get an age of 1.143 billion years.This source already had both rubidium and strontium.To make matters even worse for the claimed reliability of these radiometric dating methods, these same basalts that flowed from the top of the Canyon yield a samarium-neodymium age of about 916 million years,5 and a uranium-lead age of about 2.6 billion years!8 Physicists have carefully measured the radioactive decay rates of parent radioisotopes in laboratories over the last 100 or so years and have found them to be essentially constant (within the measurement error margins).Furthermore, they have not been able to significantly change these decay rates by heat, pressure, or electrical and magnetic fields.Nevertheless, geologists insist the radioactive decay rates have always been constant, because it makes these radioactive clocks “work”!New evidence, however, has recently been discovered that can only be explained by the radioactive decay rates not having been constant in the past.9 For example, the radioactive decay of uranium in tiny crystals in a New Mexico granite ( yields a uranium-lead “age” of 1.5 billion years.



No geologists were present when most rocks formed, so they cannot test whether the original rocks already contained daughter isotopes alongside their parent radioisotopes.Part 2 explains how scientists run into problems when they make assumptions about what happened .An hourglass is a helpful analogy to explain how geologists calculate the ages of rocks.6 The problems with contamination, as with inheritance, are already well-documented in the textbooks on radioactive dating of rocks.7 Unlike the hourglass, where its two bowls are sealed, the radioactive “clock” in rocks is open to contamination by gain or loss of parent or daughter isotopes because of waters flowing in the ground from rainfall and from the molten rocks beneath volcanoes.

Similarly, as molten lava rises through a conduit from deep inside the earth to be erupted through a volcano, pieces of the conduit wallrocks and their isotopes can mix into the lava and contaminate it.

Based on these observations and the known rate of radioactive decay, they estimate the time it has taken for the daughter isotope to accumulate in the rock.



Uranium decay dating comments


  • Dating Techniques - Uranium Series Dating - Daughter, Parent. profil de paulette60

    paulette60

    Uranium series dating techniques rely on the fact that radioactive uranium and thorium isotopes decay into a series of unstable, radioactive "daughter" isotopes; this process continues until a stable non-radioactive lead isotope is formed. The daughters have relatively short half-lives ranging from a few hundred thousand.…
  • Uranium–uranium dating - Wikipedia profil de paulette60

    paulette60

    Uranium–uranium dating is a radiometric dating technique which compares two isotopes of uranium U in a sample uranium-234 234U and uranium-238 238U. It is one of several radiometric dating techniques exploiting the uranium radioactive decay series, in which 238U undergoes 14 alpha and beta decay events on.…
  • Radioactive Dating - Carbon, Method, Earth, and Age - JRank Articles profil de paulette60

    paulette60

    The discovery of the radioactive properties of uranium in 1896 by Henri Becquerel subsequently revolutionized the way scientists measured the age of artifacts and. When the rate of decay of a radioactive substance is known, the age of a specimen can be determined from the relative proportions of the remaining.…