Development of this process was aided by German chemists Otto Hahn and Fritz Strassmann, who later went on to discover nuclear fission in December 1938.
The utility of the rubidium–strontium isotope system results from the fact that Sr with a half-life of 48.8 billion years.
The Rb-Sr dating method has been used extensively in dating terrestrial and lunar rocks, and meteorites.
If the initial amount of Sr is known or can be extrapolated, the age can be determined by measurement of the Rb and Sr concentrations and the Sr ratio.
The dates indicate the true age of the minerals only if the rocks have not been subsequently altered.
The important concept in isotopic tracing is that Sr derived from any mineral through weathering reactions will have the same Sr as the mineral.
The resulting Rb-Sr ratios and Rb and Sr abundances of both the whole rocks and their component minerals will be markedly different.
This, thus, allows a different rate of radiogenic Sr to evolve in the separate rocks and their component minerals as time progresses.
❤️ During G-Eazy’s Bud Light Dive Bar Tour, he brought Halsey out on stage. This is well known for the Cenozoic time-scale but, due to poorer preservation of carbonate sequences in the Mesozoic and earlier, it is not completely understood for older sequences.In older sequences diagenetic alteration combined with greater uncertainties in estimating absolute ages due to lack of overlap between other geochronometers (for example U–Th) leads to greater uncertainties in the exact shape of the Sr isotope seawater curve.Their newest release is called “Him & I” and it’s already on repeat.The song first debuted back in August when Halsey joined him on stage which sparked up a flurry of dating rumours.The ideal scenario according to Bowen's reaction series would see a granite melt begin crystallizing a cumulate assemblage of plagioclase and hornblende (i.e.; tonalite or diorite), which is low in K (and hence Rb) but high in Sr (as this substitutes for Ca), which proportionally enriches the melt in K and Rb.This then causes orthoclase and biotite, both K rich minerals into which Rb can substitute, to precipitate.However, because Rb substitutes for K in minerals and these minerals have different K/Ca ratios, the minerals will have had different Rb/Sr ratios.During fractional crystallization, Sr tends to become concentrated in plagioclase, leaving Rb in the liquid phase.Conversely, these fluids may metasomatically alter a rock, introducing new Rb and Sr into the rock (generally during potassic alteration or calcic (albitisation) alteration.Rb-Sr can then be used on the altered mineralogy to date the time of this alteration, but not the date at which the rock formed.