Isochron dating methods new thread


30-Sep-2020 15:29

Because the Earth formed as part of the Solar System, a second approach is to date extraterrestrial objects, i.e., meteorites and samples from the Moon.Many of these samples have not had so intense nor so complex histories as the oldest Earth rocks, and they commonly record events nearer or equal to the time of formation of the planets.The third approach, and the one that scientists think gives the most accurate age for the Earth, the other planets, and the Solar System, is to determine model lead ages for the Earth, the Moon, and meteorites.This method is thought to represent the time when lead isotopes were last homogeneously distributed throughout the Solar System and, thus, the time that the planetary bodies were segregated into discrete chemical systems.Although early stratigraphers could determine the relative order of rock units and fossils, they could only estimate the lengths of time involved by observing the rates of present geologic processes and comparing the rocks produced by those processes with those preserved in the stratigraphic record.With the development of modern radiometric dating methods in the late 1940s and 1950s, it was possible for the first time not only to measure the lengths of the eras, periods, and epochs but also to check the relative order of these geologic time units.We use cookies to make interactions with our website easy and meaningful, to better understand the use of our services, and to tailor advertising.

Present evidence indicates, however, that these intervals were rather short (100-200 million years) in comparison with the length of time that has elapsed since the Solar System formed some 4 to 5 billion years ago.The first is to search for and date the oldest rocks exposed on the surface of the Earth.