Potassium dating accuracy
Please respond with and flaws in my reasoning or any additional reasons why the experiment was flawed.edit 1 above i said Statistically significant disparity in measured ages is inconsistent with the assumptions required to make radiometric dating predictions.Here are the original claims behind the Ngauruhoe volcanic rocks from the Institute for Creation Research.If you look at the data in Table 4 you will see that only a very very small portion of the 40Ar is radiogenic (Column 40Ar*) between 1.7 and 4 percent, relative to the total 40Ar.I will award the correct answer to a response which provides links to evidence and sound explanations.Motivation for the question to follow: Some of the common mistakes we make in evaluating claims are resisting contrary evidence, looking for confirming evidence, and preferring available evidence.Geologists avoid dating glassy, polydeformed or very altered rocks with K-Ar, because these are known to sometimes be problematic .A lot of the difficulties with the K-Ar method outlined by the other user here are addressed by the newer 40Ar/39Ar method which allows for: Therefore, the 40Ar/39Ar method yields results which are considered to be more robust.
However if it is, then wouldnt this invalidate any results made using K-Ar dating?The claim shows one sample that dated to 3.5 /- 0.2 million years before present.While other answers are correct that the half-life of Potassium-40 is very large, the 0.2 MY error bars indicate that the measurements were accurate enough to establish the "age" with a high degree of certainty.The claim "the real ratio of elements would indicate a 50 year old sample" lies more than 17 standard deviations away from the mean measurement, so it is very unlikely that the sample matched that prediction. The same flow yielded samples that dated to 1.3 /- 0.3 MYA, 0.8 /- 0.2 MYA, and 1.2 /- 0.2 MYA. (One sample also dated to 270,000 years ago, which appears to be the minimum measurable value, so is not a significant aberration). These (flawed) studies cite examples of "anomalous" ages from specific lava floes: Their claims: "Volcanic rocks produced by the lava flows which occured in Hawaii in the years 1800-1801 were dated by the potassium-argon method.Radiometric dating would predict that, if the assumptions (1) and (2) hold, samples from the same flow would have the same age. Excess argon produced apparent ages ranging from 160 million to 2.96 billion years." (Kofahl and Segraves, 1975, p.200) These authors cite a study by Funkhouser and Naughton (1968) on xenolithic inclusions in the 1801 flow from Hualalei Volcano on the Island of Hawaii.