Rb sr dating equation
Popular Dating Methods Both the K-Ar and Rb-Sr methods make use of radioactive decay of a parent isotope to a stable daughter isotope. Leeman, "Late Cenozoic Alkali-Rich Basalt from the Western Grand Canyon Area, Utah and Arizona: Isotopic Composition of Strontium," Geological Society of America Bulletin, 85 (Nov. Six analyses of Uinkaret Plateau basalts (U-33, U-35, U-59, U-24, U-43, U-58) were used. For waters developed in multi-mineralic rocks or soils, Sr in any water parcel usually represents a mixture of Sr from several sources, and thus the exact contributions from individual minerals are difficult to determine with the Sr isotopic data alone.However, when considered in conjunction with water chemistry, the Sr isotopes provide a powerful tool for distinguishing among solute sources.Sr is the parameter typically reported in geologic investigations; however, some hydrogeochemists report values in "delta" units.
Because Sr has an atomic radius similar to that of Ca, it readily substitutes for Ca in minerals.
For example, sections of the soil zone affected by evaporative concentration of recharge waters or by differences in p COSr in immobile waters at a plagioclase-hornblende grain boundary versus a quartz-mica boundary will be different.