closure temperature

Coined 1973 by Martin H. Dodson.

closure temperature (plural closure temperatures)

1. (geology) The temperature, of a mineral, etc., below which there is no significant diffusion of isotopes into the external environment; the temperature of said mineral at the time it was formed (as calculated by radiometric dating).

   Synonym: blocking temperature

   • 1990, C. M. R. Fowler, The Solid Earth, Cambridge University Press, page 199:

     The relationship between the closure temperature of a mineral and its cooling history can be put onto a more rigorous footing by the use of some thermodynamics.

   • 2006, Jean Braun, Peter van der Beek, Geoffrey Batt, Quantitative Thermochronology, Cambridge University Press, page 23:

     Dodson (1973) introduced the term closure temperature, which he defined as the temperature of the thermochronological system at the time ${\displaystyle t_{c}}$ corresponding to its apparent age (cf. Figure 2.1). The closure temperature, which by definition lies between the open-system and blocking temperatures, provides the simplest conceptual entity to which a thermochronological age can be related.

   • 2020, Barbara A. Romanowicz, Seismic Tomography of the Earth's Mantle, David Alderton, Scott A. Elias (editors-in-chief), Encyclopedia of Geology, Volume 1, 2nd Edition, Academic Press, page 606,

     As the closure temperature varies for every mineral and isotopic system, a system can be closed for one mineral at some temperature but open for another.