This is made up of numerous regional tree-ring chronologies, particularly in the medieval and post-medieval periods, for which the laboratory now has more than 200 reference chronologies from many areas. By comparing the proportion of K-40 to Ar-40 in a sample of volcanic rock, and knowing the decay rate of K-40, the date that the rock formed can be determined.There are over 130 radiocarbon dating laboratories around the world producing radiocarbon assays for the scientific community. A series of movie clips walks you through the process.Because of the distortions and lies spread by fundamentalists about scientific dating there is a need for a centralized source of information on the topic.A few examples of such lies are presented at the very bottom of this page.Hutton, a Scottish geologist, first proposed formally the fundamental principle used to classify rocks according to their relative ages.He concluded, after studying rocks at many outcrops, that each layer represented a specific interval of geologic time.[ While this may be true, a shrub in Tasmania could be 40,000 years old.See Oldest Living Organism.] The Sheffield Laboratory now has a continuous master sequence for England going back to about 5000BC. This article should be a "must read" for any person interested in factualy accurate information on dating methods.
Examples of a number of consistent dates derived from different methods are given.The most compelling argument for an age of the earth of 4.5 billion years are the large number of independent tests that have been used to confirm this date.These tests have been performed on what are thought to be the earth's oldest surviving rocks, meteorites, and moon rocks.Many of these links also appear where appropriate below.James Hutton and William Smith advanced the concept of geologic time and strengthened the belief in an ancient world.