Correlations between compressional and shear wave velocities and corresponding Poisson's ratios for some common rocks and sulfide ores

The correlations between Vp and Vs and corresponding Poisson's ratios are important in modeling and interpreting seismic data in terms of chemistry and lithology. Data from high-pressure laboratory measurements of compressional and shear wave velocities (Vp and Vs) are analyzed for 12 common categories of rocks (amphibolite, anorthosite, basalt, diorite, eclogite, felsic gneiss, gabbro-diabase, granite, intermediate gneiss, limestone, mafic gneiss, and peridotite) and 4 types of massive sulfide ores (chalcopyrite, pyrite, sphalerite and pyrrhotite). The analysis reveals that the linear correlation provides good descriptions for the Vs–Vp and lnVs–lnVp relationships. Poisson's ratio is linearly correlated with Vs, Vp, shear modulus (G) and Young's modulus (E) for these rocks and sulfide ores. A decrease in Poisson's ratio is associated with increases in Vs, G and E. However, the variation of Poisson's ratio with Vp depends on the logarithmic ratio Rs/p(i.e., ∂lnVs/∂lnVp). Poisson's ratio increases or decreases with Vp when Rs/p< 1 or > 1. Rs/p varies systematically with lithology (0.300 for granite, 0.573 for diorite, 0.602 for felsic gneiss, 0.631 for intermediate gneiss, 0.721 for gabbro-diabase, 0.768 for mafic gneiss, 0.866 for eclogite, 0.890 for amphibolite, and 1.391 for peridotite). It is suggested that Rs/p can be used as a proxy for the composition of the deep continental crust and the upper mantle.