Time-domain electromagnetic data for the Spiritwood valley aquifer, Manitoba

Abstract

This Open File reports on recent time-domain electromagnetic geophysical data collected and processed by the Geological Survey of Canada as part of the Aquifer Assessment and Support to Mapping project within the Groundwater Geoscience Program. A 1062 km2 area of the Spiritwood valley aquifer in southern Manitoba has been developed as a site for testing the application of airborne electromagnetics and other surface and downhole geophysical methods for regional mapping and characterization of buried valley aquifers in Canada. In November of 2013, time-domain electromagnetic soundings were performed at selected sites to better constrain the airborne results. One-dimensional modelling and inversion of the data show marked variability in the data and the resistivity models between different geological settings. In particular, depth to bedrock is clearly resolved in the models and the incised buried valley interpreted from the regional airborne survey is associated with a relatively strong resistive anomaly indicative of coarser grained material or a high-potential aquifer.