what is a major advantage of k-ar dating over other forms of radiometric dating
K–Ar dating Due to the long half-life, the technique is most applicable for dating minerals and rocks more than 100,000 years old. For shorter timescales, it is unlikely that enough argon-40 will have had time to accumulate in order to be accurately measurable. K–Ar dating was instrumental in the development of the geomagnetic polarity time scale.[2] Although it finds the most utility in geological applications, it plays an important role in archaeology. One archeological application has been in bracketing the age of archeological deposits at Olduvai Gorge by dating lava flows above and below the deposits.[8] It has also been indispensable in other early east African sites with a history of volcanic activity such as Hadar, Ethiopia.[8] The K–Ar method continues to have utility in dating clay mineral diagenesis.[9] Clay minerals are less than 2 micrometres thick and cannot easily be irradiated for Ar–Ar analysis because Ar recoils from the crystal lattice.