Obsidian dating

Voyage into Archaeology Links, articles, and other beginner's resources in archaeology, including a simulation game called "Be a Time Detective." Glossary of Archaeological Terms What is chert? For example, the arrival of sophisticated carbon-14 dating methods in the 1940s caused scientists to revise their interpretation of events in Europe in prehistoric times.

All living beings, both plants and animals, have a mixture of radioactive C-14 and nonradioactive C-12 atoms in their organic material. The remaining C-14 atoms decay at a constant rate, allowing this process to be used reliably as an indicator of age.

This dating method is used to date obsidian, a kind of volcanic glass.

Obsidian hydration dating has provided invaluable information about population patterns in the ancient Maya center of Copán.

Seriation is a relative dating method that is used to place types of artifacts (or sites with certain artifact types) into a chronological sequence.

Adding the margin of error for carbon-14 (in this case, /- 150 years), the archaeologist can give a reliable date range for the bone: 1655-1405 B. A bone found deep in the ground will generally be older than one found close to the surface, for example.

Two bones found in the same archaeological deposit are likely to be the same age.

Year-to-year variations in climate, especially rainfall amounts, are reflected in tree rings.

A lot of rain in a given year causes thick rings, and little rainfall yields thin rings.

This sort of information helps archaeologists to put objects into an age sequence.

Relative dating does not give archaeology absolute dates that can be tied into a calendar.

Obsidian makes a useful knife blade or cutting tool, and archaeologists have found these tools while excavating settlements such as those of the ancient Maya.