Closure temperature radiometric dating select search dating service
Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert.
While uranium is water-soluble, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor sediments, from which their ratios are measured.
So, we have a “clock” which starts ticking the moment something dies.
We use the cooling histories to model fission track annealing and He retention and predict zircon and apatite fission track and apatite (U–Th)/He thermochronometric ages.These effects are corrected for by the calibration of the radiocarbon dating scale.Uranium-thorium dating method A relatively short-range dating technique is based on the decay of uranium-234 into thorium-230, a substance with a half-life of about 80,000 years.This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.