The point whose depth is determined | Type of magnetic structure | Structural index n |
Depth to surface, for edge | Fault, contact area whose depth ratio to its thickness is small | 0 |
Depth to surface, depth to center | Thin dyke, contact area whose depth ratio to its thickness is great | 1 |
Depth to center | Horizontal cylinder, vertical cylinder | 2 |
Depth to center | Magnetic sphere or magnetic bipolar | 3 |