Magnetic surveying is typically used for mapping magnetic ores and studying bedrock structures. The VLF method is particularly well suited for mapping fragile bedrock structures (e.g., fracture zones).
By using magnetic + VLF measurement, the magnetic properties of the target area can be registered with the same measurement and the most significant fragile structures of the bedrock can be mapped. The joint mapping of these features provides direct initial information to support, for example, the planning of bedrock drilling for ore exploration, as many ore deposits are connected to fragile structures of the bedrock in the area or the structures border the ore deposit.
The magnetic method is a passive method, so only a receiver is needed. Measurements are made on pre-planned lines, point-to-point or as continuous measurements. The method uses two magnetometers, one as a fixed base station and the other in the measurement.
Magnetic measurement is performed from pre-planned lines as a continuous measurement from point to point. VLF measurement is performed simultaneously on the same lines and with the same equipment at a defined point interval. The method uses one magnetometer as a fixed base station and the magnetometer+VLF equipment is moved along the lines like a regular magnetometer on foot or by skiing.
The equipment used is GemSys GSM-19W+VLF and the base station GemSys GSM-19W magnetometer.
In VLF measurement, only international general base stations can be used or a TX27 mobile VLF transmitter can be used to amplify the signal. Using a mobile base station also enables more versatile line geometry planning than using international VLF stations.
Customers always receive quality-assured raw data from the surveys. In addition, we process and analyze the data. The selected level of reporting and customer orientation to the survey results are implemented as agreed
The result of the magnetic measurement: magnetic profiles, maps and 3D models according to the agreement.
The result of the VLF measurement is the real and imaginary components of the secondary field at each point. Typically, the results are presented as a line profile. The conductivity distribution (classification of conductivity based on the Re/Im ratio), as well as the thickness of the conductive object (in the linear direction) and the slope can be interpreted.
