Radiometric dating

Argon-argon dating is a radiometric dating technique similar to potassium-argon (K-Ar) dating. Ar40 and Ar39 are the two isotopes examined in this technique. While Ar40 is a stable isotope, Ar39 has a half-life of 269 years. Therefore, in natural rock which is thousands to millions of years old, Ar39 should exist only in minute quantities. ...more on Wikipedia about "Argon-argon dating"

Before Present (BP) years are the units of time (counted backwards to the past) used to report raw radiocarbon ages and dates referenced to the BP scale origin in the year AD 1950. For example, 12,000 BP means a raw radiocarbon age equal to 12,000 years, or a raw radiocarbon date equal to 12,000 radiocarbon years before AD 1950. ** ...more on Wikipedia about "Before Present"

Carbon-13 is a stable isotope of carbon. It makes up about 1.109% of all naturally-occurring carbon on Earth. ...more on Wikipedia about "Carbon-13"

Cosmogenic isotopes are rare radioactive isotopes created when cosmic radiation interacts with an atomic nucleus. These isotopes are produced on Earth, in Earth's atmosphere, and in extraterrestrial items such as meteorites. ...more on Wikipedia about "Cosmogenic isotope"

Fission track dating is a radiometric dating technique based on analyses of the damage trails or tracks left by fission fragments in certain uranium bearing minerals and glass. Uranium-238 undergoes spontaneous fission decay at a known rate. The fragements emitted by this fission process leave trails of damage in the crystal structure of the minerals enclosing the uranium. Etching of polished surfaces of these minerals reveals the fission tracks for counting by optical microscopic means. The number of tracks correlates directly with the age of the sample and the uranium content. To determine the uranium content the sample is annealed by heating and exposed to a barrage of thermal neutrons. The neutron bombardment produces an induced fission of the uranium-235 in the sample and the resulting new tracks are used to determine the uranium content of the sample as the U-235:U-238 ratio is well known. ...more on Wikipedia about "Fission track dating"

Helium Dating (or He dating) is the method of age determination that depends on the production of helium during the decay of the radioactive isotopes uranium-235 (U-235), uranium-238 (U-238), and thorium-232 (Th-232). Because of this decay, the helium content of any mineral or rock capable of retaining helium will increase during the lifetime of that mineral or rock, and the ratio of helium to its radioactive progenitors then becomes a constant. Since radioactivity is a first order decay process, the calculation of the mineral or rock's age is trivial. ...more on Wikipedia about "Helium dating"

Isochron dating is a common technique of radiometric dating and is applied to date certain events, such as crystallization, metamorphism, shock events, and differentiation of precursor melts, in the history of rocks. Isochron dating can be further separated into mineral isochron dating and whole rock isochron dating; both techniques are applied frequently to date terrestrial and also extraterrestrial rocks ( meteorites). The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions about the initial amount of the daughter nuclide in the radioactive decay sequence are needed. Indeed the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays. ...more on Wikipedia about "Isochron dating" http://www.shortopedia.com never sleeps.

Optically Stimulated Luminescence or OSL Dating is a method of establishing the age of soil sediments. It is used by archaeologists as an alternative to radiocarbon dating. ...more on Wikipedia about "Optically stimulated luminescence dating"

Potassium-argon or K-Ar dating is a geochronological method used in many geoscience disciplines. It is based measuring the products of the radioactive decay of potassium (K), which is a common mineral found in materials such as micas, clay minerals, tephra and evaporites. ...more on Wikipedia about "Potassium-argon dating"

Radiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to ca 60,000 years . ...more on Wikipedia about "Radiocarbon dating"

Raw radiocarbon dates are usually reported in years "before present" (BP). This is the number of radiocarbon years before 1950, based on the assumption that the level of carbon-14 in the atmosphere has always been at the 1950 level. Because this is untrue in, raw radiocarbon years do not correspond exactly to calendar years. Calibrated dates that take into account these factors. ...more on Wikipedia about "Radiocarbon year"

Radiogeology is the science that deals with the relation of radioactivity to geology. Geologists can determine the age of rocks, fossils, and other objects by measuring the radioactive elements in them. ...more on Wikipedia about "Radiogeology"

Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ...more on Wikipedia about "Radiometric dating"

The rubidium-strontium dating method is a radiometric dating technique that geologists use to determine the age of rocks. ...more on Wikipedia about "Rubidium-strontium dating" shortopedia Is Good For You.

(Samarium-neodymium dating) Samarium and neodymium are rare earth elements of Group III B of the periodic table. Samarium and neodymium belong to the light rare earth elements, a group of relatively chemically inert metals. ...more on Wikipedia about "Samarium-neodymium dating"

Uranium-thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a radiometric dating technique commonly used to determine the age of carbonate materials such as speleothem or coral. Unlike other commonly used radiometric dating techniques such as rubidium-strontium or uranium-lead dating, the uranium-thorium technique does not measure accumulation of a stable end-member decay product, instead calculating an age from the degree to which equilibrium has been restored between the radioactive isotope thorium-230 and its radioactive parent uranium-234 within a sample. ...more on Wikipedia about "Uranium-thorium dating"

Uranium-uranium dating is a radiometric dating technique utilizing the comparison of two isotopes of uranium in a sample: uranium-238 and uranium-234. Uranium-uranium dating is one of several radiometric dating techniques exploiting the uranium radioactive decay series, in which U-238 undergoes 14 alpha and beta decay events while decaying to the stable isotope lead-206. Other dating techniques using this decay series include uranium-thorium and uranium-lead dating. ...more on Wikipedia about "Uranium-uranium dating"

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