Temperature and pressure effects on basalt thermal diffusivity – a review

Studying basalt thermal diffusivity under high temperature or high pressure is helpful to understand the lithospheric thermal structure and dynamics of subduction zone and to evaluate the heat-transmission mechanisms in basalt stratum. To explore the temperature and pressure effects on basalt thermal diffusivity, the authors collected data from literature reviews. A decrease in the basalt thermal diffusivity by an elevated temperature was obtained by an exponential function. An increase in basalt thermal diffusivity by pressure was found. The internal reasons of these two findings were explained by a classical physics theory. Moreover, the physical property changes by temperature and pressure are also the reasons of thermal-diffusivity change, which include crack generation, increase in porosity and decrease in density at elevated temperature and crack close, porosity decrease and grain contact under pressure.