Compressional Wave Velocities in Eclogites of the Dabieshan, Central China to 5. 0 GPa: A Preliminary Result

Abstract

The Dabie high- and ultrahigh-pressure metamorphic belt is a collisional orogen where coesite and microdiamond inclusions were found. Ten eclogite samples, five from the high-pressure (HP) belt and five from the ultrahigh-pressure (UHP) belt, were selected and measured the compressional wave velocities (V_p) in three mutually orthogonal directions. The UHF eclogites seem to have higher V_p than the HP samples at the identical pressures. The anisotropy in samples from UHP belt (4. 16 %) is less than that from HP belt (6. 37 %). Eclogite, with a possible content from 7. 8 to 16. 5 % is distributed in the crust beneath the central Dabieshan.