They may study fossil remains of animal and plant life or experiment with the flow of water and oil through rocks. Laboratory equipment used includes instruments such s the X-ray diffractometer, which determines the crystal structure of minerals, and the petrographic microscope, used for close study of rock and sediment samples. Besides locating natural resources and working in laboratories, geologists and geophysicists also advise construction companies and government agencies on the suitability of proposed locations for buildings, dams, or highways. Some administer and manage research and exploration programs. The fields of geology and geophysics are closely related but there are some major differences.
Geologists study the composition, structure, and history of the earth's crust.
They try to find out how rocks were formed and what has happened to them since their formation. Geophysicists use the principles of physics and mathematics to study the earth's internal composition, surface, and atmosphere and also various forces such as its magnetic, electrical, and gravitational fields. Geologists and geophysicists usually specialize. Geological oceanographers study the ocean bottom. They collect information using remote sensing devices aboard ships or sometimes from underwater research craft.