Potassium–argon dating (K–Ar) method
It is suitable as tectites (natural glass) usually contain quite high amount of potassium (including radioactive potassium 40). The amount of potassium is determined by mass spectometer. In the same way the amount of argon 40 can be measured. The date of origin of natural glass can be calculated from the measured figures.
The age of Moldavites was determined by the use of the above method to be 14.7 million years.
More about K-Ar dating:
- Sean D. Pitman M.D. – Radiometric Dating Methods
- Wikipedia – K–Ar dating
- The University of California – Potassium-Argon Dating
- SAO/NASA Astrophysics Data System (ADS)
- Google Scholar
Fission track dating
When uranium cores fall apart, particles with high kinetic energy are created. Such particles go through glass and leave a track 0.01 mm long (i.e. microscopic area of disruption). We can determine the age of glass by the number of tracks in a volume unit.
The age of Moldavites was determined by the use of the above method to be 14.7 million years.
More about Fission track dating: