Which of the following are usual methods for dating fossils


24-Jul-2017 05:49

which of the following are usual methods for dating fossils-82

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Coins found in excavations may have their production date written on them, or there may be written records describing the coin and when it was used, allowing the site to be associated with a particular calendar year.In historical geology, the primary methods of absolute dating involve using the radioactive decay of elements trapped in rocks or minerals, including isotope systems from very young (radiocarbon dating with Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes.Volcanic rocks – such as tuff and basalt – can be used in dating because they are formed at a particular moment in time, during an eruption.Sedimentary rocks are rarely useful for dating because they are made up of bits of older rocks.Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age.For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.As discussed before, the assumptions influence the interpretation of the data.There are three main assumptions that must be made to accept radiometric dating methods.

Instead, other methods are used to work out a fossil’s age.Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty of accuracy.