The exaggerated profile plotter (fig. 1) was designed and 
constructed for use with aerial photographs to aid in tracing and 
correlating thin rock units between field measured stratigraphic sections. 
  
Fig. 1. Exaggerated profile plotter 
Problems in geologic mapping on the western flank of the Black Hills, 
Wyoming, involving the identification, correlation, and tracing of 
contacts between formational and intraformational units of the Lakota 
and Fall River formations demonstrated the need and potential usefulness 
of such an instrument. 
The profile plotter is used with aerial photographs and a double- 
projection type stereoscopic plotter to draw vertically enlarged profiles 
that emphasize topographic detail which may reflect rock units, 
structural detail, facies changes, and some surficial deposits.