One method absolute dating
See more information about "Strata" Smith and his original geologic map of England.Information about Simon Winchester's delightful biography of Smith, The Map That Changed the World is available at Tree-Ring dating is based on the principle that the growth rings on certain species of trees reflect variations in seasonal and annual rainfall.However, human beings love to see factual precision, and we want to know how old something is.Please remember that all dating methods, even those termed "absolute," are subject to margins of error. That is a very small amount of possible error range. Modern studies almost always use two or more methods to confirm dating work and to build confidence in the results obtained.Dating is not necessary to demonstrate that evolution is a fact.Chronological sequence is all that is really required.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.
He concluded, after studying rocks at many outcrops, that each layer represented a specific interval of geologic time.Overview of Methods Superposition Stratigraphy Dendrochronology Radiocarbon C14 Radiometric Dating Methods Obsidian Hydration Dating Paleomagnetic/Archaeomagnetic Luminescence Dating Methods Amino Acid Racemization Fission-track Dating Ice Cores Varves Pollens Corals Cation Ratio Fluorine Dating Patination Oxidizable Carbon Ratio Electron Spin Resonance Cosmic-ray Exposure Dating This is an excellent overview of dating methodologies, and is a chapter in a textbook on Archaeology.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.Many of these links also appear where appropriate below.