Age calculation carbon dating
Organic materials, which require the most processing, are limited to younger ages by their corresponding process blank.Due to counting and measurement errors for the blanks and samples, statistical errors are higher for very old samples.
Some examples of the types of material that radiocarbon can determine the ages of are wood, charcoal, marine and freshwater shell, bone and antler, and peat and organic-bearing sediments.Carbon dating is used to determine the age of biological artifacts up to 50,000 years old.This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils (like those of the dinosaurs alleged to be millions of years old).In AMS, the filiamentous carbon or "graphite" derived from a sample is compressed into a small cavity in an aluminum "target" which acts as a cathode in the ion source.The surface of the graphite is sputtered with heated, ionized cesium and the ions produced are extracted and accelerated in the AMS system.Love-hungry teenagers and archaeologists agree: dating is hard.
But while the difficulties of single life may be intractable, the challenge of determining the age of prehistoric artifacts and fossils is greatly aided by measuring certain radioactive isotopes.
Carbon-14 cannot be used to date biological artifacts of organisms that did not get their carbon dioxide from the air.
This rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock.
Until this century, relative dating was the only technique for identifying the age of a truly ancient object.
By examining the object's relation to layers of deposits in the area, and by comparing the object to others found at the site, archaeologists can estimate when the object arrived at the site.
Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed).