Expert: Ralph Salier - 10/18/2002

Question
Hi.  I'm a librarian teaching a class of college students how to use the Internet.

One of the students would like to know what additional dating techniques there are other than carbon dating, argon dating, and obsidian hydration.

Thanks very much for whatever information you can provide.

Topsy

Topsy N. Smalley, Instruction Librarian
Cabrillo College Library

Answer
There are several others:

Potassium-Argon
Protien racitimization
Magnetic dating
Ceramic Thermoluminesence
Tree Ring dating
Varve Dating

Other then Potasium-Argon and Carbon 14 there are other radioactive decay clocks which are being brought into use but these are the two most common.

Protien racitimization looks at the rate at which protiens in bone "flip" and this occurs at a reasonably predictive rate.  Its usefullness is limited to about 3 to 400 years.

Magnetic dating is highly accurate (in 20 year time spans) and looks at the clay materials of a hearth which when heated fixes the magnetic particles in the direction of north at the last firing of the hearth.  This along with any charcoal may give a very precise date for the hearth.  The samples are carefully encased in plaster with the modern north indicated and then the sample is taken into the lab where it is reoriented to north and the micro manetic differences are tested and then compaired to a chart of how longago this "north" occured.

Ceramic Thermoluminesence uses a similar principal as the magnetic dating above but looks at the molecular structure under high temp to determine its magnetic seting.

Tree ring dating is rather obvious

Varve dating is similar to tree ring dating in that in sediments in ponds and other water sources, thin layers are deposited.  And like tree rings can be counted and the age of common deposits can be determined.