摘要：The origin and history of the Earth are manifested as the evolu- tionary processes of chemistry and physics of its interiors, which can be recognized by deciphering the geochemical signals recorded in minerals and rocks. Deep interiors of the Earth and other rocky planets are under both extreme pressure and temperature, i.e., approximately 360 gigapascals (GPa) and as high as 7000 K at the center of the Earth. So far, many questions on Earth's interiors remain equivocal, such as the compositions and mineralogy of the mantle and core, the causes of chemical and physical heterogene- ities of the mantle, origins of magma and petroleum, the role of fluid-rock interaction in the crustal evolution and earthquake gen- eration, the behavior and partition of elements and chemical spe- cies, chemical dynamics of the degassing process, among other processes, which have attracted much attention of scientists. The materials in the interior domains of Earth and other planets experi- ence the extreme processes of high pressure and high temperature (high P–T) conditions. Not only does high temperature, but also high pressure severely affects the behavior of atoms and molecules, chemical dynamics of reactions, and existing states of materials. However, traditional investigations usually neglect the chemical re- actions under high P–T conditions. Thus, the high P–T chemical reac- tions and processes are among the most important factors in the Earth's evolution, which are involved in various geological pro- cesses, such as mantle metasomatism, element differentiation, iso- topic fractionation, magma evolution, ore formation, alteration of rocks, earthquake generation, etc. Therefore, studies of the geo- chemical behavior of materials under high P–T conditions are fun- damental to understand the physicochemical properties of the Earth's interior. High-pressure experiments and theoretical simula- tions are powerful tools to explore the Earth's interiors in addition to the geophysical techniques, analysis of natural samples and me- teorite. This Special Issue of High Pressure Geochemistry in Geosci- ence Frontiers assembles contributions that present results of high pressure geochemistry, concerning mainly the behavior and parti- tion of elements, hydration and dehydration of minerals, origin of magma, reaction between minerals and magma, effect of chemical composition (as well as volatiles) on the transport property of min- eral/rock, gas diffusion, phase transitions and occurrence states of materials under high P–T conditions.
