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Luminescence dating methods are not radiometric dating methods in that they do not rely on abundances of isotopes to calculate age. Instead, they are a consequence of background radiation on certain minerals. Over time, ionizing radiation is absorbed by mineral grains in sediments and archaeological materials such as quartz and potassium ...
The radioactive system behind hafnium–tungsten dating is a two-stage decay as follows: 182 72 Hf → 182 73 Ta e − ν e 182 73 Ta → 182 74 W e − ν e. The first decay has a half-life of 8.9 million years, while the second has a half-life of only 114 days, [7] such that the intermediate nuclide tantalum-182 (182 Ta) can effectively be ignored.
In 1862, the physicist William Thomson, 1st Baron Kelvin published calculations that fixed the age of Earth at between 20 million and 400 million years. [21] [22] He assumed that Earth had formed as a completely molten object, and determined the amount of time it would take for the near-surface temperature gradient to decrease to its present value.
In a closed system, the amount of radiogenic isotopes present in a sample is a direct function of time and the decay rate of the mineral. [2] Therefore, to find the age of a sample, geologists find the ratio of daughter isotopes to remaining parent isotopes present in the mineral through different methods, such as mass spectrometry .
In 1994, the principles behind optical and thermoluminescence dating were extended to include surfaces made of granite, basalt and sandstone, such as carved rock from ancient monuments and artifacts. Ioannis Liritzis, the initiator of ancient buildings luminescence dating, has shown this in several cases of various monuments. [25] [26] [27]
Monazite geochronology is a dating technique to study geological history using the mineral monazite. It is a powerful tool in studying the complex history of metamorphic rocks particularly, as well as igneous, sedimentary and hydrothermal rocks. [2] [3] The dating uses the radioactive processes in monazite as a clock.
The Hallstatt plateau or the first millennium BC radiocarbon disaster, as it is called by some archaeologists and chronologists, [1] is a term used in archaeology to refer to a consistently flat area on graphs that plot radiocarbon dating against calendar dates.
Rhenium–osmium dating is a form of radiometric dating based on the beta decay of the isotope 187 Re to 187 Os. This normally occurs with a half-life of 41.6 × 10 9 y, [ 1 ] but studies using fully ionised 187 Re atoms have found that this can decrease to only 33 y. [ 2 ]