The preparation of geological maps that show the distribution of geologic units selected for representation on a map: Field geology includes the plotting of the orientation of such structural features as faults, joints, cleavage, small folds, and the attitude of beds with respect to three-dimensional space.

A common objective is to interpret the structure at some depth below the surface of the earth.

It is possible to determine, with some degree of accuracy, the structure beneath the surface by using information available at the surface of the earth.