Overview of Airborne-Electromagnetic and -Magnetic Geophysical Data Collection Using the GEOTEM Survey near Three Hills and Cochrane, Alberta

This report is the fourth in a series of eight Alberta Geological Survey (AGS) Open File Reports that provide an overview of airborne electromagnetic and magnetic geophysical surveys completed over the Edmonton-Calgary Corridor (ECC) by Fugro Airborne Surveys Ltd. These surveys were completed between November 2007 to February 2010 as part of a joint AGS and Alberta Environment and Sustainable Resource Development (ESRD) study to determine the usefulness of the RESOLVE�, GEOTEM� and TEMPEST� geophysical survey techniques in mapping the distribution and physical attributes of sediment- and bedrock-aquifer complexes over areas of formerly glaciated terrain.

This report describes data collection methods using the Fugro Airborne Surveys Ltd. GEOTEM� survey techniques and data processing completed for two study blocks near Three Hills and Cochrane, Alberta.

The ECC was selected as the first test area to support the AGS-ESRD groundwater mapping program as it represents the region with the highest rates of industrial and urban growth in the province. Since this growth will exert increasing demands on water resources in the ECC, it is necessary to reassess the spatial distribution of previously mapped, as well as unmapped aquifer complexes in the region. By doing so, Alberta may better predict and manage current and/or future stresses on existing aquifer systems caused by industrial, agricultural and urban development. Airborne geophysical survey methods were selected as one of the tools in completing this assessment.

The ECC is an ideal area to evaluate the usefulness of airborne electromagnetic and magnetic geophysical survey techniques due to the wealth of existing surficial and subsurface geological datasets (i.e., geological mapping, lithologs, petrophysical data, field observations, etc.). These datasets provide users with a means to calibrate and verify airborne geophysical data, analyses and interpretations within the ECC.