Isotopes used for radiometric dating
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.
As we pointed out in these two articles, radiometric dates are based on known rates of radioactivity, a phenomenon that is rooted in fundamental laws of physics and follows simple mathematical formulas.
Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades.
Students should be able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age.
William Smith was one of the most important scientists from this time who helped to develop knowledge of the succession of different fossils by studying their distribution through the sequence of sedimentary rocks in southern England.
Students not only want to know how old a fossil is, but they want to know how that age was determined.
This activity on determining age of rocks and fossils is intended for 8th or 9th grade students.The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.