Seismic reflection sections can show blocks of the crust in great detail. This study of one layer maps out an ancient network of sandy stream channels , much like the modern channels of the Laramie River, right. Such buried channels can yield oil or gas easily if seismic reflection work can pinpoint their locations. With these details they can plan the extraction of oil, gas, coal, or other minerals. They can also predict how ground water may flow through an area, and find the most efficient strategies to clean up contamination.
Geophysicists can also make maps of other physical properties that rocks show over an area.
Gravitational pull, magnetic field strength, electrical conductivity, radioactivity , and spectral reflectance are all properties that may be used to detect particular rock formations of economic or geologic interest, even if they are buried below the surface. The maps above are derived from maps of magnetic field strength in a part of Nevada. Computerized artificial illumination from the right direction reveals a subtle lineament in the image. A buried, slightly magnetized dike could contain gold ores. Very high-resolution geophysical methods can help geologists wishing to make detailed environmental or engineering studies of rock masses near the surface.