Geological Surveying

Geology is the study of the liquid and solid substances that form the earth. The discipline of geology includes the examination of the composition, properties, and history of the earth materials. The technique of their formation, movement, and changes involved are also studied. Geology survey is an essential engineering discipline that is important for the extraction of minerals and hydrocarbons. It includes topographic mapping that is performed by numerous surveying companies by using modern surveying instruments. Geological information can be obtained by land survey techniques to assist in mitigating damage due to natural disasters. A geological survey is concerned with the methodical study of the subsurface for creation of geological maps. Several geological techniques are used for this purpose, including the conventional visual survey, studying of landforms, hand and machine driven bore holes, remote sensing systems like satellite imagery and aerial photography.

Geological surveying has advanced due to the modern concepts evolved in all disciplines of engineering. Some of the modern

techniques used for the geological survey are as under:

• Robotic laser devices that observe and record data
• Distances measured electronically by light beams
• Use of GPS that is a satellite positioning technology
• Guidance to construction machined by laser beams and satellites
• Laser scanners for the creation of 3-D models

Numerous surveying techniques are used for geological surveys like laboratory test results, and modeling approaches to understand the characteristics of the earth. In the usual geological surveying, the primary information is concerning the study of rocks, their location, and the deformation and examination of the sedimentary layers. In addition, the soils, landscapes, rivers, and glaciers are examined. Usually the surveying tasks include:

• Geological mapping
  

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• Structural mapping to indicate the location of the main rocks and the faults due to which they were placed there
• Surficial mapping for the location of soils
• Survey of topographic features
• Formation of topographic maps
• Survey to identify changes in landscapes, erosion patterns, and river channels
• Subsurface mapping by seismic surveys, ground penetrating radar, and electrical tomography

A geological map illustrates geological features. Rock units are identified by color, while the structural features like faults and folds are indicated by symbols. A geological map is considered to be one of the major tools to communicate or decode information relating to the surface of the earth. Geological maps are mainly used for the interpretation of the structure, mineralogy, stratigraphy, and paleontology of the earth crust. Geological maps are also valuable in locating energy resources like petroleum, coal, natural gas, and geothermal resources. They are also used for the exploration of mineral deposits like gold, copper, iron, and construction aggregate. Geological maps also identify potential hazards, for which necessary precautions can be taken. They are a basic source for engineering applications.