| Abstract: | Compressional wave velocities in some Mesozoic and Cenozoic volcanic rocks from Qinling Dabie orogenic belt were measured at room temperature and high pressure (up to 4.5 GPa). Compressional wave velocities of these rocks increase with the increasing of pressure. The experiment data indicate that the pressure at which the microcracks in these rocks finally close is up to 2.0 GPa. The empirical relationships between compressional wave velocities at high pressure and oxide mass fractions, heat productions and densities at room temperature and 100 kPa of these rocks are discussed. It is likely that there does not always exist linear relationship between compressional wave velocities and oxide mass fractions. New heat production data of volcanic rock samples from the Qinling Dabie orogenic belt do not follow the empirical relationship between heat production and seismic velocity for rocks. It is dangerous to use these empirical relations to predicate the modal chemical composition, density and heat production of the lithosphere. |
