Early Geological Map of the Dakotas and Nebraska including Cretaceous Oil-Bearing Rocks
A large format map of Kansas, Nebraska, Dakota and part Colorado and Wyoming, extending as far southeast as Denver, Colorado City and St. Vrains showing the geology of this area.
The map includes excellent detail of railroads including the Union Pacific, showing two parallel routes: one ending in Denver and the other a little to the north heading into Wyoming. Dozens of forts are located on this map. Numerous routes of explorations and surveys are drawn in. This includes Captain Raynolds's 1859 expedition to the Yellowstone and Nicollet's 1839 expedition mapping the upper Mississippi. Areas roamed by the principal American Indian tribes are shown. Warren's extensive knowledge of the area and his skill as a cartographer are obvious in this large, detail-filled map.
The map shows eight geological formations ranging from granites and metamorphics [pre-Cambrian] to Paleocene fluvial sediments. This is likely the earliest map to show the oil-bearing Cretaceous sandstones of North Dakota in any detail. The two dominant structures in the map are a bullseye pattern in South Dakota and a north-south anticline in Colorado. This latter appears to be a complete guess at the geology of the Rocky Mountains, though the former observation has some merit.
One of the geological formations shown is the Potsdam Sandstone. The type locality for this building stone is in New York and extends into parts of nearby states and provinces. It unconformably overlays Proterozoic rocks. In 19th century geology, this name was given to any North American sandstone that unconformably overlaid Precambrian metamorphic rocks. Units such as these are common in North America, and typically referred to as part of the "Great Unconformity," a topic of current debate.
In this map, the Potsdam Sandstone overlays the granites of the Black Hills. Uplifted during the Laramide orogeny, they are now the core of the Black Hills, containing Black Elk Peak (the highest point in the state) and Mount Rushmore. These granites were formed during the Trans-Hudson Orogen in the Neoarchean. This map shows the Potsdam unit at the core of the bullseye, and not granites. Modern maps and logic appear to suggest otherwise, so whether this was a misinterpretation, a misprint, or something else entirely remains to be seen.
The geology was provided by Dr. Ferdinand Hayden, then Professor of Geology and Mineralogy at the University of Pennsylvania. This was surveyed only 4 years prior to his famous trip of exploration into Yellowstone that resulted in Yellowstone becoming the first National Park in the United States.
This geological survey was conducted with excess funds which remained from the establishment of the Nebraska legislature. The geologist was instructed to pay particular attention to possible building stones (of which the Potsdam was a possibility), soils, ores, elevations in mountainous areas and more. Conducted in the year of Nebraska's statehood, this survey is an exemplary study in late 19th-century geology.
States of the Map
The various states and editions of the map are identifiable as follows:
- State 1. (late 1858) Title is Military Map of Nebraska and Dakota, and portions of the States and Territories Bordering Thereon . . . . Published for the 35th Congress, First Session (1857-1858). Two column list of explorations and surveys. No information included from after 1858. Gold Regions in Colorado referenced, but no reference to either Auroria or Denver. https://www.raremaps.com/gallery/detail/69254
- State 2. (late 1858) Includes the addition of the following features (a) To the right of the title, the words "Engraving Carefully Revised G.K. Warren Lieut. Top Engrs" added; (b) Many place names added along the "Nebraska or Platte River" including the foregoing name, as well as O'Fallon's Bluff, Cotton Wood Spring, Brady's L.; (3) "River of Souls" and "Lookingglass C" are added above the Pawnees Reservation; (d) Further northwest on the route surveyed by Warren in 1857, "Loup Fork" has been added; (e) The name "Dakota River" is added; (f) The topographical features east of Laramie Peak are improved; (g) Along the White River, the words "White River" and "Mauvaises Terres or Bad Lands" are added; (h) Mouse River is added to the west of Assiniboine River; (i) Missouri River is added near St. Joseph. https://www.raremaps.com/gallery/detail/47769
- State 3: (1867) Title Changed to Map of Nebraska and Dakota Bien imprint at bottom left and revised list of explorations and surveys, with the last line (Nicollet) centered. Denver named. Significant changes, including less topographical features and river system in the west of the Platte River and south of Ft. Vrain completely revised. https://www.raremaps.com/gallery/detail/46576
- State 4: (1867 circa) List of explorers and surveys modified with the last line is left justified. No Bien imprint. Railroad routes added, including proposed routes to Denver. https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~234618~5510157:Map-Of-Nebraska-And-Dakota?sort=Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No&qvq=q:Map%20of%20Nebraska%20and%20Dakota%2C%20and%20portions%20of%20the%20States%20and%20Territories%20bordering%20thereon;sort:Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No;lc:RUMSEY~8~1&mi=0&trs=
- State 5; (1875) The map is colored to show Geological information. Bien imprint removed, exploration and survey tables removed, new title info and geological table, with final credit in title "Geology by F.V. Hayden M.D. . . ." https://www.raremaps.com/gallery/detail/67301
- State 6 (1872?): Reissue of State 2, with N. Peters Photolithographer, Washington, D.C. imprint at bottom right. www.raremaps.com/gallery/detail/69371