541360  Geophysical Surveying and Mapping Services 

This industry comprises establishments primarily engaged in gathering,
interpreting, and mapping geophysical data. Establishments in this
industry often specialize in locating and measuring the extent of
subsurface resources, such as oil, gas, and minerals, but they may 
also conduct surveys for engineering purposes. Establishments in this
industry use a variety of surveying techniques depending on the 
purpose of the survey, including magnetic surveys, gravity surveys, 
seismic surveys, or electrical and electromagnetic surveys. 

The data published with NAICS code 541360 are comprised of these parts
of the following SIC industries:
 
     1081 (pt)  Geophysical Surveying Services for Metal Mining, on a 
                Contract Basis
     1382 (pt)  Geophysical Surveying Services for Oil and Gas Fields, 
                on a Contract Basis     
     1481 (pt)  Geophysical Surveying Services for Nonmetallic 
                Minerals (Except Fuels) on a Contract Basis
     8713 (pt)  Geophysical Surveying