Solid masses that make up the earth's crust as well as accumulations of materials. Use for major rock types and unconsolidated deposits. For deposits of economic value, see related terms.
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.
Booklet giving general explanations of geologic time, major divisions of geologic time, relative and radiometric time scales, index fossils, and the age of the earth.
Site has links to Lake Mead National Recreation Area: geologic field trips, geologic history, plate tectonics, rocks and minerals, geologic time, geologic maps, and glossary.
Site has links to Mohave National Preserve: geologic field trips, geologic history, plate tectonics, rocks and minerals, geologic time, geologic maps, and glossary.
Site has links to Sunset Crater Volcano National Monument geologic field trips, geologic history, plate tectonics, rocks and minerals, geologic time, geologic maps, and glossary.
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.
Detailed background information with descriptions of sites and photos explaining the geology of this organic-rich shale unit that has recently become a significant source of natural gas resources.
Report presents an abridged guide for laboratory technicians and students using X-ray powder diffraction methodology to study crystalline structure and to determine the mineralogy of finer grained sediments, especially clays.