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在0.2～5.0GPa和室温至1400℃温压范围内,测量了上地幔主要造岩矿物橄榄石、单斜辉石和斜方辉石在大洋地温梯度和大陆地温梯度下的纵波速度。测量结果表明,在较低压力下,矿物受到破裂、压实和重结晶作用的影响而导致其测得的波速值明显偏低,可以通过较高压力下的波速测量值外推获得低压下的波速值。在不同地温梯度下随着深度的增大,地幔矿物的波速逐渐增加,压力是影响波速变化的最主要因素,温度的升高不改变波速升高的总体趋势,但在较大的深度下温度对波速的影响明显加强。主要地幔矿物在一定深度范围内出现局部波速降低的现象,与矿物相变、软化及熔融作用有关。
The P-wave velocities of olivine, clinopyroxene and orthopyroxene, the major rock-forming minerals in the upper mantle, were measured over the geothermal gradient and continental geothermal gradient at temperatures ranging from 0.2 to 5.0 GPa and room temperature to 1400 ℃. The results show that under the condition of lower pressure, the influence of the fracture, compaction and recrystallization on the minerals leads to the lower value of the measured wave velocity. By means of the extrapolation of the velocity measurements at higher pressures, Wave velocity value. Under different geothermal gradients, with the increase of depth, the velocity of mantle minerals gradually increases. Pressure is the most important factor that affects the variation of wave velocity. The increase of temperature does not change the overall trend of wave velocity increase. However, at a greater depth, the temperature The impact on the wave speed is significantly enhanced. The main mantle minerals in a certain depth range of local wave velocity decreased phenomenon, and mineral phase transition, softening and melting related.