Digital geologic maps of the US states with consistent lithology, age, GIS database structure, and format

Aerial surveys of magnetic anomaly and gamma ray emission; older surveys were analog record which have been digitized, newer surveys collected data in digital form.

National Mineral Resource Assessment 1998: Estimates of the number of undiscovered mineral resources of gold, silver, copper, lead, and zinc within identified permissive tracts (geographic areas in which mineral deposits may form).

Seventy-seven major components of the North American continent were delineated at a general scale (1:5,000,000); including the general composition, geological environment, and types of primary metals endowments that can be expected in each domain.

Systematic geochemical and mineralogical survey of soil horizons analyzed using a consistent set of methods, sample spacing 1 per 1,600 sq km.

Geochemical analysis of sediment samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are of stream sediment in the continental US and Alaska.

Geochemistry of concentrates from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US and Alaska.