Uranium decay dating

15-Feb-2015 03:11 by 7 Comments

Uranium decay dating - single mom dating edmonton

It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.

The age of a rock can be calculated if its ratio of uranium to lead is known.

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.

If a zircon crystal originally crystallizes from a magma and remains a closed system (no loss or gain of U or Pb) from the time of crystallization to the present, then the Discordant dates will not fall on the Concordia curve.

Sometimes, however, numerous discordant dates from the same rock will plot along a line representing a chord on the Concordia diagram. is then interpreted to be the date that the system became closed, and the younger date, t*, the age of an event (such as metamorphism) that was responsible for Pb leakage.

Each step in such a chain is characterized by a distinct half-life.

In these cases, the half-life of interest in radiometric dating is usually the longest one in the chain.

To see how we actually use this information to date rocks, consider the following: Usually, we know the amount, N, of an isotope present today, and the amount of a daughter element produced by decay, D*.

By definition, D* = N-1) (2) Now we can calculate the age if we know the number of daughter atoms produced by decay, D* and the number of parent atoms now present, N.

Pb leakage is the most likely cause of discordant dates, since Pb will be occupying a site in the crystal that has suffered radiation damage as a result of U decay.

U would have been stable in the crystallographic site, but the site is now occupied by by Pb.

The only problem is that we only know the number of daughter atoms now present, and some of those may have been present prior to the start of our clock. The reason for this is that Rb has become distributed unequally through the Earth over time.