Types of Geological Maps
Geological maps depict the area’s geological conditions and structures as they appear on the earth’s surface. They are built in such a way that the data obtained through systematic investigation can be plotted on a suitable topographic map. The true foundation of all geological work is geological mapping and field investigation. A good geological map shows which rocks are visible on the land surface and the stratigraphy and tectonic structure of the area. There are several kinds of geological maps and are described as follows:
- Surface geological map: Contains information about the geology beneath the surface. These maps are scaled at 1:50,000 or higher.
- Outcrop map: Describes the discovery of the rock’s location. These maps contain information about the properties of the rock as well as its structural condition. This type of map is typically large in scale.
- Overview geological map: Provides information about formations that have been revealed and the location of formation extrapolation that is still covered by a Holocene layer. These maps are typically scaled at 1:100,000 or less.
- Structure map: The appearance of the depth lines on the structure map explains certain layers beneath the surface. Scale: medium to large.
- Schematic geological map: Geological data is based on topography.
- Thematic geological map: A geological map that contains information about natural resources and potential energy in specific locations.
- Topography map: Displays the height of an area as contour height measured against the average sea level.
- Isopach map: Represents lines that connect formations or layers of the same thickness without the need for structural support. The scale of this map is generally medium to large.
- Photogeological map: The result of aerial photographs that have been adapted to the actual field conditions.
- A hydrogeological map depicts the state of groundwater in a specific location and whether the formation is permeable or impermeable.