Phase Transitions in Mantle Rocks

摘要: Phase transitions of silicates and oxides relevant to the Earth’s mantle have been discussed in previous chapters. In this chapter, we focus on phase transitions in mantle rocks and related materials. PyrolitePyrolite represents the average upper mantleUpper mantlecomposition. Oceanic lithospheresOceanic lithosphere subducting into the deep mantle have a layered structure consisting of overlying basaltic crustCrust, residual harzburgiteHarzburgite, and depleted pyrolite from top to bottom. The phase transition behaviors of basalt, harzburgite and pyrolitePyrolite are significantly different, which results in density differences among the rocks. The density differences lead to the subduction or stagnation of basaltic crustCrustand harzburgiteHarzburgite in the transition zoneTransition zone and the lower mantleLower mantle. In addition, phase transitions in subducted continental crustContinental crust materials are …