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Chronometric dating techniques in archaeology


It is widely accepted by both geologists and astronomers that Earth is roughly billion years old. This age has been obtained from the isotopic analysis of many meteorites as well as of soil and rock samples from the Moon by such dating methods as rubidium–strontium and uranium–lead . It is taken to be the time when these bodies formed and, by inference , the time at which a significant part of the solar system developed. When the evolution of the isotopes of lead-207 and lead-206 is studied from several lead deposits of different age on Earth, including oceanic sediments that represent a homogenized sample of Earth’s lead, the growth curve of terrestrial lead can be calculated, and, when this is extrapolated back in time, it is found to coincide with the age of about billion years measured on lead isotopes in meteorites. Earth and the meteorites thus have had similar lead isotope histories, and so it is concluded that over a period of about 30 million years they condensed or accreted as solid bodies from a primeval cloud of interstellar gas and dust—the so-called solar nebula from which the entire solar system is thought to have formed—at about the same time.

When and how did life emerge on Earth? How did humanity develop a civilization? Is there other intelligent life out there?


Chronometric dating techniques in archaeology

Chronometric dating techniques in archaeology