Rubidium strontium dating range

28-Jul-2016 06:54

Rubidium is a soft, silvery-white metallic element of the alkali metal group, with an atomic mass of 85.4678.Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, including rapid oxidation in air.We know that Rb preferentially goes into the crust. Thus, the Sr-87/Sr-86 ratio of the crust increases over time.Likewise, because the mantle is depleted in Rb, the Sr-87/Sr-86 ratio of the mantle decreases over time.During fractional crystallization, Sr tends to concentrate in plagioclase, leaving Rb in the liquid phase.

However, because this is a small number and counting atoms isn’t easy, it is more useful to use the ratio of one isotope to another.This means that as partial melting occurs, Rb is going to partition to the melt in greater proportion than Sr will.From this partitioning, the mantle will become depleted in Rb relative to Sr.On Earth, natural rubidium comprises two isotopes: 72% is the stable isotope, Rb, with a half-life of 49 billion years—more than three times longer than the estimated age of the universe.German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy.

However, because this is a small number and counting atoms isn’t easy, it is more useful to use the ratio of one isotope to another.

This means that as partial melting occurs, Rb is going to partition to the melt in greater proportion than Sr will.

From this partitioning, the mantle will become depleted in Rb relative to Sr.

On Earth, natural rubidium comprises two isotopes: 72% is the stable isotope, Rb, with a half-life of 49 billion years—more than three times longer than the estimated age of the universe.

German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy.

As with potassium (which is slightly less reactive) and caesium (which is slightly more reactive), this reaction is usually vigorous enough to ignite the hydrogen gas it produces.