Thus both the approximate age and a high time resolution can be obtained.
Rhyolites in Yellowstone N. Assume D3, P3, and N3 in source 3, all zero. Thus, it always better to date minerals that have high K contents, such as sanidine or biotite. The 26 Al — 26 Mg chronometer gives an estimate of the time period for formation of primitive meteorites of only a few million years 1. There are quite a number of mechanisms in operation in a magma chamber.