Thermocronology is a branch of geology that studies the thermal history of rocks and minerals over geological time. In other words, it allows us to reconstruct when a rock cooled as it rose toward the Earth’s surface due to processes such as:
Many minerals contain radioactive elements that decay over time. Thermochronology takes advantage of this process to determine cooling ages.
Each method has a “closing temperature”—that is, the temperature below which the isotopic clock begins to record time.
By combining several methods, it is possible to reconstruct the complete thermal history of a region.
The most commonly used minerals are:
Fission Tracks. Analyzes microscopic damage caused by the spontaneous fission of uranium. It is widely used in:
(U–Th)/He. Measures helium produced by radioactive decay. Widely used in:
Ar/Ar. Uses radioactive argon to study thermal histories at higher temperatures.
Thermocronology is used in: