geothermometry

Geothermometry in Earth science involves the study of temperature within the Earth. This can refer to the use of a geologic thermometer, which is a mineral or mineral aggregate that provides information about the temperature conditions under which it formed. Alternatively, it can refer to a geothermometer, a thermometer designed to measure temperatures in deep-sea deposits or boreholes.12

Temperature is a critical variable in metamorphism, the process by which rocks change due to heat and pressure. Metamorphic temperatures can range from approximately 150–200 °C up to the point where rocks begin to melt, around 650–1,200 °C, depending on the rock's composition. The temperature at any given point within Earth's crust is influenced by factors like heat flow from the mantle, radioactive decay, and the movement of hot rocks. The increase in temperature per unit distance of depth is known as the geothermal gradient, which varies significantly across different geological settings. Temperature-gradient measurements can also be used to detect heat-flow anomalies and explore for geothermal resources.34