Here is one example of an isochron, based on measurements of basaltic meteorites (in this case the resulting date is 4.4 billion years) [Basaltic1981, pg. Skeptics of old-earth geology make great hay of these examples.
Using logs recovered from old buildings and ancient ruins, scientists have been able to compare tree rings to create a continuous record of tree rings over the past 2,000 years.This tree ring record has proven extremely useful in creating a record of climate change, and in finding the age of ancient structures. The thick, light-colored part of each ring represents rapid spring and summer growth.The thin, dark part of each ring represents slow autumn and winter growth.Several other processes result in the accumulation of distinct yearly layers that can be used for dating.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.Radiocarbon dating can easily establish that humans have been on the earth for over twenty thousand years, at least twice as long as creationists are willing to allow.Therefore it should come as no surprise that creationists at the Institute for Creation Research (ICR) have been trying desperately to discredit this method for years.In regions outside the tropics, trees grow more quickly during the warm summer months than during the cooler winter.This pattern of growth results in alternating bands of light-colored, low density "early wood" and dark, high density "late wood".9), the K-Ar method cannot be used to date samples that are much younger than 6,000 years old (Dalrymple, 1991, p.