¶ … role of potassium argon dating within the field of archaeology. How it works and what methods are used to glean the date from archaeological artefacts and remains.
Potassium argon and the archaeologist
The majority of the world's archaeological sites are now so ancient that there is no actual way of giving them a complete and secure chronological date that radio-carbon dating can provide. However, here are many techniques for dating within the field of archaeology, one of these methods is the K-Ar (Potassium-Argon) method which has been a vast success within the field of geology (the study of earth).
It is possible to date rocks with a low potassium content such as basalts in this way. Sadly the dates are not always secure due to the behaviour of the geochemicals of the parent and daughter elements as they are likely to being disturbed by geological events such as weathering or reheating that normally take place during the formation of a rock. Potassium argon dating allows scientists to date volcanic rocks between two billion and 100,000 years old.
Many of the early hominid sites are found in volcanically active regions, tools used by our earliest ancestors can be found in cooled lava rock fragments or the ash remains of sporadic eruptions at the time. It has been these instances that have allowed archaeologists to...
Famous finds in this regions have been found at Olduvai Gorge along with many others.
Potassium argon dating as noted above concerns the elements that are found within the minerals within the earth's crust. In its natural form potassium only contains a small amount of radioactive K40 atoms. With every 100 K40 atoms that decay only 11% become argon, this is an inert gas that escapes its major material by a process of diffusion when lava and an other igneous rocks are formed.
However, as the volcanic rocks begins to form and crystallize the argon 40 concentration drops back to almost nothing, yet the process of decay of K40 still continues, 11% of the every K40 then in its turn becomes argon 40. this makes it possible for a spectrometer to measure concentration of argon 40 that has been collected since the volcanic rock originally formed.
Potassium argon dating has been found in many igneous rocks and materials including biotite and muscovite. The rocks are crusted, concentrated and treated with hydrochloric acid that removes any atmospheric argon from the sample. Various gases are then removed; the argon gas is then isolated and tested with a subjection to mass spectrographic analysis.
Once the age sample is determined through calculating the use of argon 40 and potassium 40 and…
