论文部分内容阅读
P- and S-wave velocities in eclogites and granulites from the Dabie ultrahigh pressures (UHP) meta-morphic belt, China, were measured at room temperature under the hydrostatic pressures up to 1.0 GPa. The ultrahigh pressure eclogites had the highest densities (3.3-3.6 g·cm-3), high velocities and the lowest anisotropy (1.4% -2.6%). The lowest densities (2.8-3.1 g·cm-3) and the highest Poisson’s ratios (0.28-0.29) were found in granulites, whereas the strongest anisotropies (6.1% - 8.4%) were found in the high-pressure (HP) eclogites. Comparison of the velocities in rocks with that observed in the deep seismic sounding profile crossing Dabieshan suggests that e-clogites might exist in the lower crust of Dabieshan, but the quantity might be small. The upper mantle has very similar velocities as the UHP eclogites and serpentinizated/water-bearing dunite. The formation of eclogite represents the crust-mantle recycling processes. Crustal material is delaminated and sinks into the mantle by way of eclogite,
P-and S-wave velocities in eclogites and granulites from the Dabie ultrahigh pressures (UHP) meta-morphic belt, China, were measured at room temperature under the hydrostatic pressures up to 1.0 GPa. The ultrahigh pressure eclogites had the highest densities (3.3 -3.6 g · cm -3), high velocities and the lowest anisotropy (1.4% -2.6%). The lowest densities (2.8-3.1 g · cm -3) and the highest Poisson’s ratios (0.28-0.29) were found in granulites Comparison of the velocities in rocks with that observed in the deep seismic sounding profile crossing Dabieshan suggests that e-clogites might exist in the lower crust of Dabieshan, but the quantity might be small. The upper mantle has very similar velocities as the UHP eclogites and serpentinizated / water-bearing dunite. The formation of eclogite represents the crust-mantle recycling processes. Crustal material is delaminated and sinks into the mantle b y way of eclogite,