Radiometric dating, often called radioactive dating, is a technique used to determine the age of materials such as rocks. It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. It is the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself, and it can be used to date a wide range of natural and man-made materials. The best-known radiometric dating techniques include radiocarbon dating, potassium-argon dating, and uranium-lead dating. By establishing geological timescales, radiometric dating provides a significant source of information about the ages of fossils and rates of evolutionary change, and it is also used to date archaeological materials, including ancient artifacts. The different methods of radiometric dating are accurate over different timescales, and they are useful for different materials.
Radiometric Age Dating - Geology (U.S. National Park Service)
Radioactive dating uses the decay rates of radioactive substances to measure absolute ages of rocks, minerals and carbon-based substances, according to How Stuff Works. Scientists know how quickly radioactive isotopes decay into other elements over thousands, millions and even billions of years. Scientists calculate ages by measuring how much of the isotope remains in the substance. The key to an age of a substance is the decay-product ratio. The ratio of the original isotope and its decay product determines how many half-lives have occurred since the sample formed. A half-life measures the time it takes for one half of a radio isotope's atoms to break down into another element.
Lake Turkana has a geologic history that favored the preservation of fossils. Scientists suggest that the lake as it appears today has only been around for the past , years. The current environment around Lake Turkana is very dry. Over the course of time, though, the area has seen many changes. Over time the sediment solidified into rock.
Isotopic analysis is typically conducted by hydrologists, biologists, and geochemists. There are many different isotopes, but they all generally fall into two categories; radioactive or stable. Radioactive isotopes have known decay rates and half-lives, which are very useful for dating particular fluids or materials. There are many applications of isotope geochemistry, some which have been utilized for geothermal exploration.