Experimental Estimation of Compressional Velocities of a Series of Swedish Crystalline Rocks and Ores

More than 50 samples were collected and measured for their physical properties including P- and S-wave velocities at both atmospheric and elevated pressures using 0.5 MHz P- and S-wave transducers in a rock physics lab at Curtin University. The rock samples are geographically from two major mining camps in northern and central parts of Sweden with samples ranging from mineral deposits, volcanic rocks to deformed and metamorphosed rocks, and from a region with unique alkaline and carbonatite rocks in the north-central part of Sweden. A few of the rock samples were also measured using a low-frequency (10-50 Hz) apparatus to provide comparison with the ultrasonic velocity measurements. Using a laser interferometer device, rock samples from a major deformation zone were measured for their elastic anisotropy with preliminary results demonstrating that a major reflection zone observed from the deformation zone could be partially enhanced by anisotropy than purely by acoustic impedance contrast. Results may also indicate that some of the coarse grain massive sulphide deposits, in contrary with what generally thought, show a very little acoustic impedance contrast with their host volcanic rocks. Iron deposits show a large acoustic impedance contrast with their hostrock, making them favorable target of seismic methods.