Clinopyroxene thermobarometry

Clinopyroxene thermobarometry is a scientific method that uses the mineral clinopyroxene to determine the temperature and pressure of the magma when the mineral crystalized. Clinopyroxene is found in many igneous rocks, so the method can be used to determine information about the entire rock. Many different minerals can be used for geothermobarometry, but clinopyroxene is especially useful because it's a common phenocryst in igneous rocks and easy to identify, and the crystallization of jadeite, a type of clinopyroxene, implies a growth in molar volume, making it a good indicator of pressure. The data given by this technique is used for understanding magmatic crystallization, prograde and retrograde metamorphism, and ore deposit formation. Understanding these processes can aid industries as well as the scientific community. With this data, information about the lithosphere composition can be extrapolated in more detail, and the diamond exploration industry can determine the probability that a kimberlite contains diamonds. Thermobarometry uses equilibrium constants to calculate information about the environmental conditions present during the rocks' formation. While each rock is forming, it reacts with the surrounding elements until it cools down enough to become inert. Each mineral within the rock will cool and crystalize at different points; a petrogenetic grid is a useful way to visualize each mineral crystalizing in sequence. Individual reactions of specific minerals can be used to calculate either the temperature or pressure. Therefore, two different reactions are needed to calculate both the temperature and pressure of the magma for a single rock. Some reactions are better for pressure and others are better for temperature, based on thermodynamics and Le Chatelier's Principle. This technique requires each reaction to be calibrated, which is done through experimentation and data analysis.