GEOLOGICAL SURVEY

A 'geological survey' is the systematic investigation of the subsurface of a given piece of ground for the purpose of creating a geological map or model.
A geological survey employs techniques from the traditional walk-over survey, studying outcrops and landforms, to intrusive methods, such as hand augering and machine driven boreholes, to the use of geophysical techniques and remote sensing methods, such as aerial photography and satellite imagery.
Geological survey can also be the national or federal institution employed to maintain the geological inventory and advance the knowledge of geosciences for the benefit of the wealth and health of the nation.
Some examples of national geological surveys are listed here:

★ BRGM - BRGM website

★ British Geological Survey - BGS website

★ Geological Survey of Canada

★ Geological Survey of India

★ Saudi Geological Survey

★ United States Geological Survey

★ German Federal Institute for Geoscience and Resources
Individual states or provinces may also have a geological survey. Examples include:

★ Pennsylvania Geological Survey

★ Ontario Geological Survey - [1]