forage sonique

CONT: ""Sonic"" drilling is a relatively new exploration technique that has some particular advantages for certain applications. The method provides continuous (disturbed) samples in a wide range of soil types with large particles that preclude sampling by many other techniques. The drill stem and sampler barrel are vibrated vertically at frequencies between about 50 and 180 Hz (hence the name sonic) such that the sampler barrel normally advances by slicing through the soil.