Geological surveying 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.
A geological survey map typically superimposes the surveyed extent and boundaries of geological units on a topographic map, together with information at points (such as measurements of orientation of bedding planes) and lines (such as the intersection of faults with the land surface).
The maps and reports created by geological survey organisations generally aim for geographic continuity and completeness in establishing the spatial patterns of near-surface rock units.
Subsurface maps typically depict the three-dimensional form of geological surfaces by means of contours and cross sections.
Computer-based models are increasingly used to provide more comprehensive information storage and greater flexibility of presentation.