Figure 4. Magneto-stratigraphic profile in the Coleman field area. The Crowsnest Formation is associated with a magnetic high and can be regarded as a "marker bed," allowing geologists to map structures based on magnetic response. KWp Wapiabi Formation; KCa Cardium Formation; KBk Blackstone Formation; KC Crowsnest Formation; KBl Blairmore Group. A and B illustrate that TMI profile values may or may not mimic topography.