ANSWER: Relative dating is used to determine the relative ages of geologic strata, artifacts, historical events, etc.
This technique does not give specific ages to items.
Each of these minerals has a different initial rubidium/strontium ratio dependent on their potassium content, the concentration of Rb and K in the melt and the temperature at which the minerals formed.
Rubidium substitutes for potassium within the lattice of minerals at a rate proportional to its concentration within the melt.
In addition, Rb is a highly incompatible element that, during partial melting of the mantle, prefers to join the magmatic melt rather than remain in mantle minerals. The radiogenic daughter, Sr, is produced in this decay process and was produced in rounds of stellar nucleosynthesis predating the creation of the Solar System.
Different minerals in a given geologic setting can acquire distinctly different ratios of radiogenic strontium-87 to naturally occurring strontium-86 (Sr as the parent melt.
Ice core sampling normally uses the assumption that the ring bands observed represents years.
Aspartic acid is the compound most often used because it has a of 15,000-20,000 years and allows dates from 5,000-100,000 years to be calculated.
Other problems of contamination have occurred, so the technique is not fully established.
It is fairly reliable for deep-sea sediments as the temperature is generally more stable.
Exploring this series of exhibits will take you on a journey through the history of the Earth, with stops at particular points in time to examine the fossil record and stratigraphy.
The Geology Wing is organized according to the geologic time scale.