Dating the earth
A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.If the solar system formed from a common pool of matter, which was uniformly distributed in terms of Pb isotope ratios, then the initial plots for all objects from that pool of matter would fall on a single point.Those which appear the most frequently in talk.origins are reproduced below: Note that these aren't necessarily the "best" or most difficult to refute of young-Earth arguments.However, they are quite popular in modern creation-"science" literature (even though they should not be!Unfortunately, the age cannot be computed directly from material that is solely from the Earth.
The current level of helium in the atmosphere would accumulate in less than two hundred thousand years, therefore the Earth is young.
Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.
The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods).
Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years.
Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenland, Australia, Africa, and Asia.
Search for dating the earth:
For example: Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.