Relative and absolutechronometric dating techniques
If a certain kind of pollen is found in an archaeological site, scientists can check when the plant that produced that pollen lived to determine the relative age of the site.
Absolute dating methods are carried out in a laboratory.
With sensitive instrumentation, this range can be extended to 70,000 years.
In addition to the radiocarbon dating technique, scientists have developed other dating methods based on the transformation of one element into another.
Dendrochronology: Also known as tree-ring dating, the science concerned with determining the age of trees by examining their growth rings.
Half-life: Measurement of the time it takes for one-half of a radioactive substance to decay.
The successive layers of rock represent successive intervals of time.
Eventually, the entire ecosystem (community of plants and animals) of the planet, including humans, is filled with a concentration of carbon-14.
As long as an organism is alive, the supply of carbon-14 is replenished.
These include the uranium-thorium method, the potassium-argon method, and the rubidium-strontium method. Thermoluminescence (pronounced ther-moeloo-mi-NES-ence) dating is very useful for determining the age of pottery.
When a piece of pottery is heated in a laboratory at temperatures more than 930°F (500°C), electrons from quartz and other minerals in the pottery clay emit light.