Magnetometry is a completely noninvasive surface geophysical method that measures the intensity of the Earth's magnetic field. Changes in its values show a change in the measured magnetic properties of the medium. Therefore, the method can be used in regional geology studies (identification of magmatic structures), on a local scale and even in engineering geology practice (detecting subsurface pipelines, finding unexploded ordnance). It is also used in archaeological research to map buried buildings and furnaces.
The territory of Poland is covered with a semi-detailed surface mapping of the total magnetic field anomaly (ΔT), with the density of measurement points varying between 2 and 6 pts/km2. The quality of the image meets the highest European standards. The measurement database contains approximately 1 million records. A perfect complement to the semi-detailed mapping are numerous detailed mapping studies of both the total magnetic field intensity and its vertical component ΔZ.
All magnetic data were included in the Central Geological Database. They can be used together with gravity data e.g. in NW and NE Poland for detailed analysis of the Precambrian basement. Density of measurements in this region enable constructing 1: 100 000 scale structural maps. In the Sudetic and Silesian-Cracow region, they are useful in the search for mineral resources and mapping of volcanic and igneous rocks enhanced magnetization. In the Polish Lowlands, it can be employed to identify structures in the sedimentary cover (including prospective for hydrocarbon exploration). Geophysical Methods Unit offers the performance of both new magnetic mapping surveys, as well as various types of data listings from the Central Geological Database
- Base maps and images (unprocessed)
- Transformed maps and images:
- Using classical methods (local anomalies, horizontal and vertical derivatives, reduction to the pole etc.)
- Using unconventional visualization methods developed in the PGI
- Data interpretation, including magnetic and gravity-magnetic modelling.
EQUIPMENT AND SOFTWARE
- Scintrex ENVIMAG Magnetometer, ENVI GRAD/MAG option – a set used to measure the strength and vertical gradient of the magnetic field
- Scintrex ENVIMAG Magnetometer, ENVI MAG/VLF option – a set used to measure the strength of the magnetic field and VLF
Data processing and interpretation is made using:
- A package of U.S. Geological Survey computer programs
- GRAVMAG software for magnetometric modelling, developed by the British Geological Survey
- A package of GEOSOFT computer programs for modelling and qualitative interpretation of gravity and magnetic anomalies maps
Zdzisław Petecki, Dr
Energy Security Program
Tel. +48 22 45 92 463
Olga Rosowiecka, Dr Eng.
Energy Security Program
Tel. +48 22 45 92 535
Mobile 607 702 272