Grid and flight-line data files provided by the geophysical survey contractors.

Gridded data for aeromagnetic surveys with contractors' reports describing the data collection

Gravity measurements to support regional mapping and hydrologic studies

Site-by-site information on 876 natural occurrences of asbestos reported within the conterminous US. Includes location, mineralogy, geology, and relevant literature for each asbestos site. Data are provided in Microsoft Excel, shapefile, and CSV formats.

Physical properties (density, magnetic susceptibility, and remanent magnetism) from 20,000 rock samples. Data are provided in CSV format.

Improved information on deposit model (type) in records of this older USGS database describing sites that are located in California. Includes a list of additional deposit types needed to properly categorize the California locations. Data are provided in Microsoft Excel, CSV, and Esri personal geodatabase (Microsoft Access) formats.

Geochemical data from selected USGS projects from the 1960s-1980s that were previously not published as digital data. Includes geochemical analyses from 36,498 samples of various types using analytical methods and instruments that were current when those studies were carried out. Data are provided in Microsoft Access, shapefile, and CSV formats.

Magnetotelluric data collected in 1989 and 1990 using USGS portable truck mounted systems that measure the distribution of electrical conductivity beneath the surface of the earth. This release provides digital information previously collected, recovered and reformatted for use with modern software. Data are provided in MT/EMAP formats.