Electromagnetic (EM) anomalies:
a review of digital data
SIGEOM is Québec's GIS geomining information system. This unique tool contains a geoscience database full of information collected over 150 years. Constantly evolving, SIGEOM is supplied with new data from geological, geochemical and geophysical surveys carried out across Québec.
|The results of airborne geophysical surveys are an important component of SIGEOM. The electromagnetic (EM) anomaly database, combined with other types of data available in SIGEOM, is an exceptional tool for the mineral industry. It makes it possible, at minimal cost, to identify new exploration targets in Québec. In this regard, from 1969 to 1997, the gouvernement du Québec funded 59 magnetic and electromagnetic surveys. The surveys cover 204 NTS map sheets at 1:50,000. They were first published on paper in reports of the DP series. Then, in the mid-1990s, the data was converted and disseminated in digital format.
(PDF Format, 1,8 Mb
(Available in French)
The Ministère des Ressources naturelles et de la Faune recently revised the numeric data relating to EM anomalies available in SIGEOM. From now on, all the information will be fully consistent with data from the original surveys in terms of position and characteristics such as conductivity-thickness (conductance) and magnetic field values.
The revised EM anomaly data will be accessible in July 2006 through E-sigeom à la carte. It will be possible to order it by unit or by lot, on NTS map sheets at a scale of 1:50,000. The files will be provided in ArcView (SHAPE) or MapInfo (MID/MIF) formats.
For more information about SIGEOM: