What is Geological map?
[[Image:World geologic provinces.jpg|thumb|300px|Global geologic provinces]] A '''geological''' or '''geologic map''' is a special-purpose [[map]] made to show [[geological]] features. [[William Smith (geologist)|William Smith]] made the first geological map of [[England]]. [[Rock (geology)|Rock]] units or [[strata]] are shown by colour or symbols which show where they are exposed at the surface. Three-dimensional features like [[fault (geology)|faults]], [[fold (geology)|folds]], with symbols which give these features' orientations. [[Stratigraphy|Stratigraphic]] [[contour line]]s may be used to illustrate the surface of a selected [[strata]] illustrating the subsurface [[Topography|topographic]] trends of the strata. [[Isopach map]]s detail the variations in thickness of stratigraphic units. It is not always possible to show this properly: the strata may be extremely fractured, mixed, or otherwise disturbed. There are often gaps ([[discontinuity|discontinuities]]) where [[erosion]] has removed strata. [[File:North america terrain 2003 map.jpg|thumb|300px|left|Geologic map of [[North America]] superimposed on a [[shaded relief]] map]] == Related pages == * [[Topographic map]] [[File:Geological map Britain William Smith 1815.jpg|thumb|[[William Smith (geologist)|William Smith's]] geologic map]] {{clear}} {{science-stub}} [[Category:Geology]] [[Category:Maps]]