Potassium argon dating accuracy
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
Technical details on how these dates are calculated are given in Radiometric dating. As with any experimental procedure in any field of science, these measurements are subject to certain "glitches" and "anomalies," as noted in the literature.
Other objections raised by creationists are addressed in [Dalrymple2006a].
The overall reliability of radiometric dating was addressed in some detail in a recent book by Brent Dalrymple, a premier expert in the field. 80-81]: These methods provide valid age data in most instances, although there is a small percentage of instances in which even these generally reliable methods yield incorrect results.
The material on this site is targeted to a broad spectrum of scientific, religious and social movements.
However, no advertisements or solicitations to support any organization (scientific, academic or religious) are allowed. This article summarizes the conclusions of the three Q&A sections below, and sketches some promising directions for an intellectually honest common ground between science and religion.
Q&A: Evolution, Creationism and Intelligent Design (28 articles).
Acknowledgments: The editor wishes to acknowledge many useful comments and contributed material from numerous friends and colleagues, including Glenn Branch, Brent Dalrymple, Peter Hess, Mark Isaak, Duane Jeffery, Kenneth Miller, Steven Peck, Eugenie Scott and others.
Also, as the authors of the 1968 article were careful to explain, xenoliths cannot be dated by the K-Ar method because of excess argon in bubbles trapped inside [Dalrymple2006].
Thus in this case, as in many others that have been raised by skeptics of old-earth geology, the "anomaly" is more imaginary than real.
In a related article on geologic ages (Ages), we presented a chart with the various geologic eras and their ages.
In a separate article (Radiometric dating), we sketched in some technical detail how these dates are calculated using radiometric dating techniques.