Radiometric dating notes
In 2013 the K–Ar method was used by the Mars Curiosity rover to date a rock on the Martian surface, the first time a rock has been dated from its mineral ingredients while situated on another planet.
Wiens has a Ph D in Physics, with a minor in Geology.
After the recrystallization of magma, more Ca being the most abundant isotope.
Thus, the amount of calcium originally present is not known with enough accuracy to be able to measure the small increase produced by radioactive decay.
K–Ar dating was instrumental in the development of the geomagnetic polarity time scale.