The Sudbury region is one of Canada's richest mining areas. This elliptical feature known as the Sudbury Basin is believed to have been formed by a meteorite impact nearly 2 billion years ago. Nickel and copper ore has been mined for more than a century from more than 90 mines distributed around the rim of the Basin. Much remains to be learned about the structural evolution of the Sudbury Basin and the mineralized showings around it. The area is typical of the southern Canadian Shield, a glaciated rocky peneplain, with a thin drift cover which supports the coniferous and deciduous forest cover.
Structure is expressed by differential erosion controlled by fractures, dykes and lithology.
The vertical magnetic gradient image, obtained from the Geological Survey of Canada shows geological units as expressed from their magnetic signatures. The variation in the concentration of magnetic minerals can be used to trace rock units. Magma filled dykes also have highly magnetic signatures. The other colours shown on the synergy image correspond to different rock types with different magnetic signatures. These types of synergy images are used more frequently by geologists and mining companies to assist in geological mapping.