Potassium argon dating problems
Morris cited other examples of anomalous dates produced by excess argon and falsely claimed that it is a universal problem for K-Ar dating.
The individual ages from each heating step are then graphically plotted on an age spectrum or an isochron.However, the Argon, a noble gas, constitutes approximately 0.1-5% of the Earth's present day atmosphere.Because it is present within the atmosphere, every rock and mineral will have some quantity of Argon.The monitoring of the interfering reactions is performed through the use of laboratory salts and glasses.For example, to determine the amount of reactor produced Ar ratio of the glass is then measured in the mass spectrometer to determine the correction factor that must be applied to the rest of the samples in that irradiation.The isotopes the KAr system relies on are Potassium (K) and Argon (Ar).
Potassium, an alkali metal, the Earth's eighth most abundant element is common in many rocks and rock-forming minerals.
Traditionally, this primary standard has been a hornblende from the Mc Clure Mountains, Colorado (a.k.a. Once an accurate and precise age is determined for the primary standard, other minerals can be dated relative to it by the Ar technique (e.g. However, while it is often easy to determine the age of the primary standard by the K/Ar method, it is difficult for different dating laboratories to agree on the final age.
Likewise, because of heterogeneity problems with the MMhb-1 sample, the K/Ar ages are not always reproducible.
Potassium can be mobilized into or out of a rock or mineral through alteration processes.
Due to the relatively heavy atomic weight of potassium, insignificant fractionation of the different potassium isotopes occurs.
Mechanical crushing is also a technique capable of releasing argon from a single sample in multiple steps.