What information is obtained from radioactive dating
Like most absolute chronometers, obsidian dating has its problems and limitations.Specimens that have been exposed to fire or to severe abrasion must be avoided.This feature is beautifully seen in the seasonal progression of plant Oensingen, Switz.
Practical experience indicates that the constant is almost totally dependent on temperature and that humidity is apparently of no significance.
Although no hydration layer appears on artifacts of the more common flint and chalcedony, obsidian is sufficiently widespread that the method has broad application.
In a specific environment the process of is the time since the surface examined was freshly exposed.
These so-called Green River Shales also contain abundant freshwater-fish fossils that confirm deposition in a lake. Because the average thickness of a varve is about 0.015 centimetre (0.006 inch), the lake is thought to have existed for more than 5 million years.
Each of the examples cited above is of a floating chronology—Sweden, by contrast, it has been possible to tie a glacial varve chronology to present time, and so create a truly absolute dating technique.