Strike and dip 2

Stratum compass to measure strike and dip direction in one step

Strike and dip refer to the orientation or attitude of a geologic feature. The strike of a bed, fault, or other planar feature is a line representing the intersection of that feature with a horizontal plane.
On a geologic map this is represented with a short straight line segment oriented parallel to the compass direction of the strike. Strike can be given as either a quadrant compass bearing (N25°E for example) in terms of east or west of north or south, a single three digit number representing the azimuth, where the lower number is usually given (where the example of N25°E would simply be 025, and the other value of 335 is discarded), or the azimuth number followed by the degree sign (example of N25°E would be 25° or 335°). The dip gives the angle below the horizontal of a tilted bed or feature, and is given by the number (0°-90°) as well as a letter (N,S,E,W) with rough direction in which the bed is dipping. One technique is to always take the strike so the dip is 90° to the right of the strike, in which case the redundant letter following the dip angle is omitted. The map symbol is a short line attached and at right angles to the strike symbol pointing in the direction which the planer surface is dipping down. The angle of dip is generally included on a geologic map without the degree sign. Beds that are dipping vertically are shown with the dip symbol on both sides of the strike, and beds that are flat are shown like the vertical beds, but with a circle around them. Both vertical and flat beds do not have a number written with them.