Radioactive dating wiki

29 Apr

Uranium-thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a radiometric dating technique commonly used to determine the age of calcium carbonate materials such as speleothem or coral.

The geomagnetic polarity time scale was calibrated largely using K–Ar dating.

In contrast, uranium is soluble to some extent in all natural waters, so any material that precipitates or is grown from such waters also contains trace uranium, typically at levels of between a few parts per billion and few parts per million by weight.

As time passes after the formation of such a material, uranium-234 in the sample, with a half-life of 245,000 years, decays to thorium-230.

It may be used to date a wide range of natural and man-made materials.

Fossils may be dated by taking samples of rocks from above and below the fossil's original position.