- The PPT/PDF document "Geochronology I Power Point Presentation,..." is the property of its rightful owner.
As rubidium easily substitutes chemically for potassium, it can be found doing so in small quantities in potassium-containing minerals such as biotite, potassium feldspar, and hornblende.
(The quantity will be small because there is much more potassium than rubidium in the Universe.) This means that if we wanted to date a rock, and if there was no Sr present initially.
The various reservoirs within the solid earth will have different values of initial Nd ratios, especially with reference to the mantle.
The usefulness of Sm-Nd dating is the fact that these two elements are rare earths.
Geochronologists have a variety of decay systems to work with. By downloading content from our website, you accept the terms of this agreement.
Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials.
Geochronology I Power Point Presentation, PPT - Doc Slides - Chapter 2. For Sr: Slide7Isochron Dating In the general case:we have two unknowns, R0 and t (we measure R and R0). If we have two samples with (presumably) identical R0 and t, subtracting one from the other, we have: Rearranging:or Slide8Isochrons From equ.
Slide4Case where some daughter already present D, daughter; D* =N0 â N, radiogenically produced daughter Since some daughter is initially present (D0): Its more convenient to work with ratios than absolute numbers, so we divide by the amount of another, non-radioactive, non-radiogenic isotope.
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.