Role of radioactive elements in dating events and artifacts
This is an informational tour in which students gain a basic understanding of geologic time, the evidence for events in Earth’s history, relative and absolute dating techniques, and the significance of the Geologic Time Scale.
Occasionally sites are partially or completely excavated to address specific research questions or to salvage information prior to disturbance by a development project.
All data recovered are thoroughly analyzed following scientific inquiry procedures before conclusions are reached.
Archaeologists also reexamine data, such as artifact collections, site records, and published reports from previously completed projects.
In contrast, radiocarbon forms continually today in the earth’s upper atmosphere.
And as far as we know, it has been forming in the earth’s upper atmosphere since the atmosphere was made back on Day Two of Creation Week (part of the expanse, or firmament, described in Genesis 1:6–8). Cosmic rays from outer space are continually bombarding the upper atmosphere of the earth, producing fast-moving neutrons (subatomic particles carrying no electric charge) (Figure 1a).1 These fast-moving neutrons collide with atoms of nitrogen-14, the most abundant element in the upper atmosphere, converting them into radiocarbon (carbon-14) atoms.
Ever wonder how scientists concluded the age of the earth to be about 4.6 billion years old or how geologists determined the ages of caverns, rocks, volcanoes and the Himalayas? Well, scientists are able to answer all of these wondrous questions and more by use of a process called radiometric or radioactive dating.
In the 1860's, English physicist Lord Kelvin disagreed with Charles Lyells proposition that the earth behaves in a uniform, unchanging manner.Radioactive dating uses the ratios of isotopes and their specific decay products to determine the ages of rocks, fossils and other substances.Elements occur naturally in the earth, and they can tell us a lot about our Earth's past. They may gather new data by conducting regional surveys to locate archaeological sites. Archaeologists use several processes to address questions about the past.
When an atom varies in the number of neutrons, the variation is called an isotope. During radioactivity, the unstable isotope breaks down and changes into a different substance.