Strike and dip
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Image:Stratum compass-clar hg.jpg Strike and dip refer to the orientation or attitude of a geologic feature. The strike of a stratum or planar feature is a line representing the intersection of that feature with the horizontal. On a geologic map this is represented with a short straight line segment oriented parallel to the compass direction of the strike. Strike is usually given as a compass bearing (N25°E for example) in terms of east or west of north. The dip gives the angle below the horizontal of a tilted stratum or feature. The symbol is a short line attached and at right angles to the strike symbol pointing in the direction of inclination. Typically the angle of dip is included on a geologic map. Strike and dip are determined in the field with a compass and clinometer or combination known as a Brunton compass.
Any planar feature can be described by strike and dip. This includes sedimentary bedding, geologic faults and fractures, cuestas, igneous dikes and sills, metamorphic foliation and any other planar feature in the Earth.
[edit] See also
[edit] References
- Lahee, Frederic H., 1961, Field Geology, 6th ed., McGraw-Hill
- Tarbuck, Edward J. and Frederick K. Lutgens, 2002, Earth: an Introduction to Physical Geology, 7th ed. Prentice Hall, ISBN 0-13-092025-8
