Geological structures are not often cylindrical and can result from complex deformation histories. Lineament is one of the complex structures on the land surface. It is a linear feature in a landscape that is an expression of an underlying geological structure such as a fault. Typically, a lineament is comprised of a fault-aligned valley, a series of fault or fold-aligned hills, a straight coastline or a combination of these features. Fracture zones, shear zones and igneous intrusions such as dykes can also give rise to lineaments. Lineaments are often apparent in geological or topographic maps and can appear on aerial or satellite photographs or aeromagnetic maps.