Isotopic geochemistry has several principal roles in geoscience. One is about the interpretation of geologic structures(magma, rocks, subduction zones...) with enrichment or depletion of certain isotopic species ( you can read a text : link ) about this topic and the other is radiometric age dating. Today we gonna talk about the second role.
Radiometric dating calculates the age of geological structures. The method uses short-life radioactive elements.Such as carbon-14, or potassium-14/argon-40. Every original element has a half-life.(For instance: Potassium-40 1,25 billion years ; Carbon-14 : 5,730 years) Every element has a different price. C-14 is 300 dollars.
Flint,1972 (link)
"It is useful to combine a variety of isotopic methods to determine the complete history of crustal rock. Since the 1980s two technological advancements have greatly increased the geologist’s ability to compute the isotopic age of rocks and minerals. The SHRIMP (Sensitive High Mass Resolution Ion Microprobe) enables the accurate determination of the uranium-lead age of the mineral zircon, and this has revolutionized the understanding of the isotopic age of formation of zircon-bearing igneous granitic rocks. Another technological development is the ICP-MS (Inductively Coupled Plasma Mass Spectrometer), which is able to provide the isotopic age of zircon, titanite, rutile, and monazite. These minerals are common to many igneous and metamorphic rocks. Carbon-14 is a radioactive isotope of carbon (carbon-12 and carbon-13 are stable isotopes) with a half-life of 5,570 years. Carbon-14 is incorporated in all living material, for it is derived either directly or indirectly from its presence in atmospheric carbon dioxide. The moderately short half-life of carbon-14 makes it useful for dating biological materials that are more than a few hundred years old and less than 30,000 years old. It has been used to provide a correlation of events within this time span, particularly those of the Pleistocene Epoch involving the Earth’s most recent ice ages".( John W. Harbaugh and Brian Frederick Windley)( more info link ).
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