Geologic, or geological, maps document geological features, including: rock units, geologic strata, bedding planes, and structural features such as faults and folds.

Drawn by “Scribe-of-the-Tomb” Amennakhte in 1150 BCE, the oldest existing geologic map – the Turin Papyrus Map – was discovered at Deir el-Medina in Thebes, and accurately documents the location of sandstone deposits and nearby gold deposits, and the distribution of local rock types.

Nicolas Desmarest's 1768 comparative study of the Auvergne volcanoes and the columns of the Giant's Causeway of Ireland provided the basis for what is considered to be one of the earliest geologic maps of the “modern” era: François Pasumot’s “Map of Part of Auvergne, or figures of, The Current of Lava in which Prisms, Balls, Etc. are Made from Basalt,” printed in 1771. Pasumot not only references Desmarest’s study, but refers to it as a kind of companion to the “Map of part of Auvergne.”

William Maclure holds the distinction of creating the first geological map of the United States. Over the course of a two-year survey period beginning in 1807, Maclure mapped every contemporary U.S. state; it’s estimated he “crossed and recrossed the Allegheny Mountains some 50 times.” The resulting geologic map shows the distribution of “five classes of rock in what are now only the eastern states of the present-day US.”

Lehi F. Hintze Geological Reconnaissance Maps of Oregon, 1936-1958
The Lehi F. Hintze Geological Reconnaissance Maps of Oregon consist of geologic maps prepared and assembled by Hintze for much of the state of Oregon. Most of the maps are compilations of published geologic mapping, unpublished geologic mapping done by graduate students at Oregon State College and the University of Oregon, and mapping by Hintze. The maps in Series III are published geologic maps, many of which have been annotated by Hintze. The maps reflect geologic mapping done from the mid-1930s through the 1950s. Most of the maps are hand-colored and have copious annotations indicating the sources of the information or noting questions or corrections. Some of the maps include cross sections. The maps vary in scale from 1:24,000 to 1:400,000; most of the maps are 1:62,500 or 1:125,000 scale. In addition to mapping done by Hintze, the maps document geologic mapping done by Edwin T. Hodge, W.D. Wilkinson, Howel Williams, William H. Taubeneck, and Robert G. Coleman.

Lincoln County, Oregon, Chronic Geologic Hazard Maps, 1994
The Lincoln County, Oregon, Chronic Geologic Hazard Maps consist of detailed maps, at a scale of 1:4,800, depicting geologic hazards that constantly affect the coast, such as landslides and shoreline erosion. The maps were prepared and published by the Oregon Department of Geology and Mineral Industries. The collection also includes a report explaining the maps and an accompanying erosion rate database. The database is available in electronic form on a 3.5-inch floppy disk.

State of Oregon Maps Collection, 1866-2000
The State of Oregon Maps Collection includes a diverse selection of maps of Oregon. The collection includes single-sheet maps of the full state of Oregon and detailed maps of specific areas. Maps of counties, cities, and regions of the state are included. Topics of the maps include geology, soils, agriculture, recreation, traffic flow, dams and reservoirs, land use, and physiography. Most of the maps depict roads, city and town locations, and political boundaries. City and county maps include street names, buildings, and historical sites. All regions of the state are represented in the collection, including all counties and many cities and towns. Maps of Corvallis and Benton County are in a separate collection. Series 2, Earth Sciences Maps, consists of maps depicting the geology, soils, hydrology, and geophysics of Oregon (Folders 04, 05, and 06). The bulk of the geologic maps were prepared in the 1940s-1970s during the years preceding, during, and immediately following the development of the scientific theory of plate tectonics.

Maps of Washington (State) and the Pacific Northwest, 1863-1994
The Maps of Washington (State) and the Pacific Northwest consist of historic and superseded maps depicting forest resources, geology, public lands and land use, hydroelectric projects, highways, and railroads in Washington and the Pacific Northwest region. Most of the maps in the collection are of all or part of the State of Washington. Regional maps depict Oregon, Washington, Idaho, Montana, and, in some cases, California and Wyoming. The maps were created by various U.S. government agencies, State of Washington departments, and private organizations. Series 3 is comprised of geologic maps, primarily of Washington (Folder 03). A soil map of the Pacific Northwest and a map of earthquakes in Washington and Oregon are also included.

SCARC's holdings include collections comprised entirely of geological maps - like several of those listed above - and collections which include geological maps. You can find additional geological maps in SCARC collections by visiting our website, and searching for "geologic."