Physics Journal of the Indonesian Physical Society
CHARACTERISTCS OF COMPRESSIONAL-WAVE VELOCITY IN ULTRAMAFIC ROCKS
Research Center for Physics LIPI, Bandung 40135, Indonesia
Seismic-wave velocities in rocks are controlled by several factors, such as types of minerals and their composition, porosity, and fabrics or mineral preferred orientation. Velocity measurements of ultramafic rocks, which consist mainly of olivine and pyroxene, demonstrate that seismic-wave velocities are greater in rocks having greater olivine composition and low porosity. In addition, rock fabrics have more control on the magnitude of anisotropy, in which rocks having strong fabrics tend to show greater anisotropy, and vice versa.