Relative vs Absolute Dating
Dating is a technique used in archeology to ascertain the age of artifacts, fossils and other items considered to be valuable by archeologists. There are many methods employed by these scientists, interested in the old, to get to know the age of items. It is possible to tell the number of years ago a particular rock or archeological site had been formed. Two broad categories of classification methods are relative dating and absolute dating. Though using similar methods, these two techniques differ in certain ways that will be discussed in this article.
As the name implies, relative dating can tell which of the two artifacts is older. This is a method that does not find the age in years but is an effective technique to compare the ages of two or more artifacts, rocks or even sites. It implies that relative dating cannot say conclusively about the true age of an artifact. Absolute dating, on the other hand is capable of telling the exact age of an item using carbon dating and many other techniques that were not there in earlier times.
Relative dating makes use of the common sense principle that in a deposition of layers. A layer that is higher is of later age than a layer that is lower in order. This means that the oldest are the strata that are lying at the bottom. However, age of deposition does not mean the age of artifacts found in that layer. Artifacts found in a layer can be compared with other items found in layers of similar age and placed in order. However, archeologists still require further information to find out the items that are oldest and those that are youngest in the order.
It is left for absolute dating to come up with the precise age of an artifact. This type of dating employs many dating techniques like atomic clocks, carbon dating, annual cycle methods, and trapped electron method. Dendrochronology is another of the popular method of finding the exact age through growth and patterns of thick and thin ring formation in fossil trees. It is clear then that absolute dating is based upon physical and chemical properties of artifacts that provide a clue regarding the true age. This is possible because properties of rock formations are closely associated with the age of the artifacts found trapped within them.
The most popular method of radio dating is radio carbon dating which is possible because of the presence of C-14, an unstable isotope of carbon. C-14 has a half life of 5730 years which means that only half of the original amount is left in the fossil after 5730 years while half of the remaining amount is left after another 5730 years. This gives away the true age of the fossil that contains C-14 that starts decaying after the death of the human being or animal.
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In brief: Relative Dating vs. Absolute Dating • Dating techniques are used in archeology to ascertain the age of old artifacts and a broad classification of these methods bifurcates them in relative dating and absolute dating • Relative dating comes to a conclusion based upon the study of layer formation of rocks. Upper most layers are considered the youngest while the lowermost deposition is considered as oldest. • Relative dating does not tell the exact age, it can only compare items as younger and older. • Absolute dating techniques can tell the exact age of an artifact by employing various techniques, the most popular being C-14 dating.
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