Revised geologic time scale indicating the ages of the lower bounds of chronostratigraphic and geochronologic units as they are currently known. Modifications to those ages made since the previous time scale was released (2007) are clearly marked.
Summaries of geologic projects in cooperation with the National Park Service including Grand Canyon National Park, Lake Mead National Recreation Area, Golden Gate National Recreation Area, Joshua Tree National Park, Yosemite National Park, and others.
Coordinated studies of the effect of historical mining for mercury, origin and composition of metals in groundwaters and surface waters, history of volcanic and intrusive activity, and the complex geological history of this area.
Links to volcanism, volcanic history, volcanic rocks, and general geology by state, by region, national parks and national monuments and a brief introduction to volcanism around the U.S. entitled: Windows into the past.
Overview of the Core Research Center (CRC) in Denver for preserving valuable rock cores for permanent storage and making the cores available for examination and testing. Includes links to services, well reports, and resources.
The Crater Lake Data Clearinghouse website is a gateway to information and data on Crater Lake with links to data downloads of bathymetry, maps and imagery, a fly-by movie, photos, and information on geology, maps, history, and biota.
Use of diatoms in biostratigraphy, coastal and estuarine studies, paleoceanology, paleoliminology, earthquake studies, environmental quality and forensic studies. Includes listing of USGS diatom projects and links to other diatom websites.
Publication (PDF format) in three parts on the biostratigraphy and lithostratigraphy of the Ibexian Series in the North American Ordovician, with sections on the southern Egan Range, Nevada and the biostratigraphy of the eastern Great Basin.
Map of Pleistocene pluvial lakes in the western Great Basin (Nevada, eastern California, southern Oregon). Includes metadata, online PDF map view, and downloadable ArcInfo export files, ArcView shapefiles, and TIFF files.
Rocks representing a variety of tectonic and depositional environments outcrop along the canal and towpath and reveal the geologic history of the central Appalachian region from the Mesoproterozoic to Jurassic Period.
Links to information on the formation and structure of Chesapeake Bay including online reports, recent field work, field work archives, cooperating agencies, bibliography, and links to articles about other terrestrial impact craters.
Brief description of vertebrates and use of their fossil bones and footprints to aid in dating strata in biostratigraphy and to decipher past climates and recreate ancient ecosystems in paleoecology, paleoclimatology and paleobiogeography.
Information on mollusks and uses of the identification of fossil mollusks in the fields of biostratigraphy, geochronology, paleocoeanography, paleoecology and ecosystems history. Links to experts and related USGS projects.
Colored map compiled by merging geologic and topographic maps of the United States through computer processing and enhancement with links to panoramic movie using QuickTime, descriptions of features, and a game entitled Puzzle of Regions.
Site with a series of articles showing how chemists and geologists use analytical chemistry to determine the age of the Earth, determine Earth's history, predict volcanic eruptions, observe long-term atmospheric change and study pollution.