Olivine thermal diffusivity influencing factors

Thermal diffusivity is one of the fundamental-thermal parameters for evaluating heat transmission efficiency in the earth. The thermal diffusivity of upper mantle matters has a significant value to digitize the temperature equilibration. Peridotite with the main mineral olivine, as an important rock of upper mantle, plays a considerable role in the heat transmission in the earth. To analyze the factors influencing on olivine thermal diffusivity, this paper summarized the data from a number of literatures relating to olivine and analyzed the internal reasons for its changes with elevated temperature and pressure. The changes of olivine thermal diffusivity are divided into 3 types. Thermal diffusivity decreases drastically at low temperatures in each type, while it has a different change law at high temperature. Even so, the classical physics theory, physical properties, heat radiation and partial melting were used to explain the internal reasons of those changes successfully. Besides, the relationships of thermal diffusivity and pressure and oxidation are expressed simply.