Thermochronology is the study of the thermal evolution of a region of a planet. Thermochronologists use radiometric dating

Radiometric dating

Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...

 along with the closure temperature

Closure temperature

In radiometric dating, closure temperature or blocking temperature refers to the temperature of a system, such as a mineral, at the time given by its radiometric date. In physical terms, the closure temperature at which a system has cooled so that there is no longer any exchange of parent or...

s that represent the temperature of the mineral being studied at the time given by the date recorded, to understand the thermal history of a specific rock, mineral, or geologic unit. It is a subfield within geology

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, and is closely associated with geochronology

Geochronology

Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

.

A typical thermochronological study will involve the dates of a number of rock samples from different areas in a region, often from a vertical transect along a steep canyon, cliff face, or slope. These samples are then dated. With some knowledge of the subsurface thermal structure, these dates are translated into depths and times at which that particular sample was at the mineral's closure temperature. If the rock is today at the surface, this process gives the exhumation rate of the rock.

Common isotopic systems used for thermochronology include fission track dating

Fission track dating

Fission track dating is a radiometric dating technique based on analyses of the damage trails, or tracks, left by fission fragments in certain uranium-bearing minerals and glasses...

 in zircon

Zircon

Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. A common empirical formula showing some of the range of substitution in zircon is 1–x4x–y...

 and apatite

Apatite

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, chlorapatite and bromapatite, named for high concentrations of OH−, F−, Cl− or Br− ions, respectively, in the crystal...

, potassium-argon

Potassium-argon dating

Potassium–argon dating or K–Ar dating is a radiometric dating method used in geochronology and archeology. It is based on measurement of the product of the radioactive decay of an isotope of potassium into argon . Potassium is a common element found in many materials, such as micas, clay minerals,...

 and argon-argon dating in apatite, uranium-thorium-helium dating in zircon and apatite, and ⁴He/³He dating.