Very Low Frequency Electromagnetic

Very Low Frequency Electromagnetic (VLF-EM) VLF-EM surveying is carried out with a combination magnetometer and VLF-EM receiver. This instrument is designed to measure the electromagnetic component of the very low frequency field (VLF-EM) which is transmitted from various stations within North America. In all electromagnetic prospecting, a transmitter induces an alternating magnetic field (called the […]

Magnetic Surveying

Magnetic surveing using a magnetometer and VLF-EM to find minerals, an example of geophysics.

  Magnetic Surveying Magnetic surveying works by detecting disturbances in the earth’s magnetic field – in mineral exploration these disturbances are usually caused by magnetite and pyrrhotite, the only two commonly occurring magnetic minerals. It works by detecting the presence of these minerals in varying concentrations, as follows: Magnetite and pyrrhotite may occur with economic […]