Dating is not necessary to demonstrate that evolution is a fact.Chronological sequence is all that is really required.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.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.
You may find it useful for the clear definitions, and for excellent links on a variety of topic.A short but clear explanation about radioactive isotopes commonly used for determining ages of rocks (with graphics) and putting numbers on the geologic time scale, extending it back before the occurance of abundant index fossils.This is a relatively new method intended to to improve the precision of uranium and thorium istopy methods.[ 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.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.These tests have consistently given the same ages for each of these objects.Examples of a number of consistent dates derived from different methods are given.It excludes contamination and weathering of travertines and makes possible more precise dating of thin deposits of secondary carbonates.No web-based resource for this method is available.