Blatchford Lake, NT Airborne Gravity Gradiometry Survey
Principal Investigator: Miles, Warner F. (5)
Licence Number: 14876
Organization: Geological Survey of Canada, NRCan
Licensed Year(s): 2011
Issued: Feb 19, 2011
Project Team: Dr. Alan Galley (Program Manager, TGI4, Geological Survey of Canada), Warner Miles (Project Leader, Geological Survey of Canada), Régis Dumont (Geophysicist, Geological Survey of Canada)

Objective(s): To acquire high-resolution airborne gravity gradient and magnetic data.

Project Description: The objective of the airborne survey is to acquire high-resolution airborne gravity gradient and magnetic data. Airborne gravity gradiometry surveys measure small variations in the rate of change of the gravity field due to lateral variations in the mass and density of underlying bedrock. Aeromagnetic surveys measure magnetic properties of bedrock and are one of the tools used in geological mapping. The bedrock locally contains mineral deposits, specifically rare-earth elements (REE) such as europium, terbium and dysprosium. Understanding these geophysical data will help geologists map the area, assist mineral exploration activities, and provide useful information necessary for communities, aboriginal associations, and government to make land use decisions. It will support potential future ground-based geological mapping and to provide basic information to support mineral exploration

The survey will consist of approximately 4,100 line km of surveying flown at a line spacing of 250 m for traverse lines and 1250 m for orthogonal control lines. The flying height will be determined by a smooth draped surface with a minimum terrain clearance of 100 m. The variations in the earth’s gravity and magnetic field will be measured from the aircraft. Please note that aircraft will not touch down except at municipal airports. There will be no ground-based surveying.

The Blatchford Lake airborne gravity gradiometer survey proposed in this application is the precursor to potential field modeling studies, mineral deposit studies, and bedrock geological mapping. These activities would be based on the results of this airborne geophysical survey and will be communicated through community engagement with Yellowknives Dene First Nation, the Lutsel K’e First Nation, and the Deninu K’ue First Nation (Fort Resolution).

The data will be made available on-line for free download through the Geoscience Data Repository for Gravity Data ( The data will be published as maps available digitally for free download through NRCan’s MIRAGE application (

The fieldwork for this study will be conducted from February 1, 2011 to March 31, 2011.