Closure temperature
In radiometric dating, closure temperature refers to the temperature at which a system, such as a mineral, no longer exchanges parent or daughter atoms with the external environment. This temperature varies broadly between different minerals and also differs depending on the parent and daughter atoms being considered.
Table of values
The following are the closing temperatures of certain minerals grouped by the typical dating method with which they are used.
Potassium-argon method
| Mineral | Closure temperature (C) |
|---|---|
| Hornblende | 530±40 |
| Muscovite | ~350 |
| Biotite | 280±40 |
| Microcline | 130±15 |