Isotopic age dating patterson
Very briefly, to radiometrically date rocks with uranium and lead isotopic abundances, you need an unaltered sample of rocks (at least 2) of the same age.
Within each rock, you measure the ratios of each set of lead isotopes (Pb The plot shows the ratios of lead isotopes in meteorite samples, with 3 isochrones plotted as solid lines.
TY - JOURT1 - Cosmogenic, radiogenic, and stable isotopic constraints on groundwater residence time in the Nubian Aquifer, Western Desert of Egypt AU - Patterson, Leslie J. Dissolved gases were measured in some of the deep groundwater samples.
Measured 4He concentrations indicate accumulation of radiogenic 4He that is qualitatively consistent with the age progression indicated by the 36Cl/Cl ratios, but the flux of external 4He from the underlying crust has not been quantified and is not constant throughout the aquifer.
Traces of this Carolinidian belt are preserved in a few isolated fragments within the Caledonian fold belt.Patterson of course did not do science in a vacuum.His discovery was possible because of the work of many other researchers before him.The slope of the isochrone is used to calculate the age of the rock (here, 4.55 billion years is the best fit line in the middle).This method allows us to calculate the ages of rocks formed at the same time.
The new isotopic data reveal the existence of very old rocks in the hinterland — away from the direction of thrusting—of the East Greenland Caledonian belt.