Established in 1966, GeoRef is produced by the American Geosciences Institute and is now one of the most comprehensive databases for the geosciences (or earth science, as it is sometimes known).  Some specific topics covered include:

• Environmental and engineering geology
• Hydrology
• Economic geology
• Geophysics
• Petrology
• Paleontology
• Marine geology and oceanography
• Mineralogy.

This focus lends itself well to use by those studying geology, engineering, environmental sciences, archeology, and similar disciplines.  Students can search a number of different formats, like journal articles, books, maps, conference papers, and reports in order to find information dating back to 1785.