Free Republic
Browse · Search
Smoky Backroom
Topics · Post Article

To: Coyoteman

Radiometric dating????

Radiometric dating

By measuring the amount of radiocative decay of a radioactive isotope with a known half-life, geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods.

* Radiocarbon dating. This technique measures the decay of Carbon-14 in organic material (e.g. plant macrofossils), and can be applied to samples younger than about 50,000 years.
* Uranium-lead dating. This technique measures the ratio of two lead isotopes (Pb-206 and Pb-207) to the amount of uranium in a mineral or rock. Often applied to the trace mineral zircon in igneous rocks, this method is one of the two most commonly used (along with argon-argon dating) for geologic dating. Uranium-lead dating is applied to samples older than about 1 million years.
* Uranium-thorium dating. This technique is used to date speleothems, corals, carbonates, and fossil bones. Its range is from a few years to about 700,000 years.
* Potassium-argon dating and argon-argon dating. These techniques are used to date igneous and volcanic rocks. They are also used to date volcanic ash layers within or overlying paleoanthropologic sites. The younger limit of the argon-argon method is a few thousand years.

Other radiogenic dating techniques include:

* Fission track dating
* Cosmogenic isotope dating
* Rubidium-Strontium dating
* Thorium-lead dating
* Neodymium-samarium dating
* Rhenium-osmium dating
* Lutetium-hafnium dating
* Paleomagnetic dating

If you are going to mention dating, please pick from the following.


953 posted on 12/20/2005 1:47:44 PM PST by benjibrowder (Part of the evil Republican Death Machine (just joking))
[ Post Reply | Private Reply | To 910 | View Replies ]


To: benjibrowder
If you are going to mention dating, please pick from the following.

My post of that handsome young lad included the original source, and that has all of the footnotes. You should check them out for more information on the dating method used.

I am not sure why are you asking me to pick one method of radiometric dating from that long list you posted.

OK, I'll bite. I am partial to carbon 14 dating.

1,006 posted on 12/20/2005 2:06:05 PM PST by Coyoteman (I love the sound of beta decay in the morning!)
[ Post Reply | Private Reply | To 953 | View Replies ]

Free Republic
Browse · Search
Smoky Backroom
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson