Strike and Dip

Strike and Dip 

in geology, the characteristics of the position—or the elements of the bedding—of a layer of rock, the roof of a magmatic massif, vein, or other geological body, or such surfaces as the surface of a tectonic fault relative to the sides of the horizon and the horizontal plane.

The strike is a line formed by the intersection of the horizontal plane with the surface of a layer of rock or another geological body set in an inclined or vertical position. The direction of the strike is expressed by its azimuth. The dip is a line on the plane of a layer or another geological body that extends perpendicularly to the strike in the direction of the inclination of the layer, which is the line of greatest steepness. The orientation of the dip line is determined by its azimuth and dip angle. The azimuth is measured by a projection of the dip line on the horizontal surface, and the dip angle is formed by the dip line and the horizontal projection of the dip line.

Strike and dip are either measured by a dip compass or determined by geological maps, sections, boreholes, mine excavations, geophysical data, or the aerial photographs of layers.

A. E. MIKHAILOV