Carbon and Potassium Argon Dating essays

Carbon and Potassium Argon Dating essays There are two dating techniques I will quickly discuss. The first I will address is carbon dating, the second is Potassium-Argon dating. Carbon is used for the dating of once living material. To begin, there are three principle isotopes of carbon which occur naturally. These are C12, C13 and C14. Of these three, the first two are stable while the third is unstable, or radioactive which means it will slowly decay. The radiocarbon method is based on this decay or the rate of decay of the radioactive or unstable carbon isotope 14 (14C), which is formed in the upper atmosphere through the effect of cosmic ray neutrons upon nitrogen 14. The reaction is: (Where n is a neutron and p is a proton). Now, C14 is rapidly oxidized into 14CO2 which enters the planets animal life through photosynthesis and the animal food chain. C14 will also disperse into the oceans as dissolved carbonate. Since all life is made up of carbon, all life will intake carbon into the organism, in approximately the same natural ratios that C12, C13 and C14 exist in the atmosphere. These ratios remain steady until the organism dies. At which point its metabolism starts and C14 slowly begins to seep out (decay). This decay is what is measured. However radiocarbon dating is only usable for a dating span of about 1,000,000 years ago. Potassium-Argon dating is the only viable technique for dating very old archaelogical materials. This method has been used to date rocks up to 4 billion years old (almost the creation of the earth). Potassium-Argon dating is based on the fact that some of the radioactive isotope of Potassium-40 (K-40), decays to the gas Argon as Argon-40 (Ar-40). By comparing the ratios of K-40 to Ar-40 in a sample of volcanic rock when you know the decay rate of K-40, then date that the rock formed can be determined. This dating technique is possible because when rocks are heated to their melting point, any Ar-40 ...