Current Map Indexes

Burlington Quad

Centerville Quad

Dyersburg Quad

Harrison Quad

Jefferson City Quad

Joplin Quad

Kansas City Quad

Lawrence Quad

Moberly Quad

Paducah Quad

Poplar Bluff Quad

Quincy Quad

Rolla Quad

St. Louis Quad

Springfield Quad

Tulsa Quad

Future Map Indexes

Nebraska City

Online Geologic Maps
This Site Is Under Construction

To view listings of completed quads, please click
on entries to the right under "Current Map Indexes."

Geologic maps show the distribution, composition, age, and structure (folds, faults, etc.) of the various solid materials that make up Earth's crust. The two most common types of geologic maps are bedrock maps and surficial materials maps. Bedrock geologic maps show the distribution (outcrop pattern) of competent rock (bedrock). They reveal what the pattern of bedrock would look like if all non-bedrock materials (soil, sediments, etc.) were stripped away from the surface. Surficial materials geologic maps, on the other hand, show the distribution of the various unconsolidated materials (soils, sediments, etc.) that cover bedrock.

Geologic maps are used for decision making in 1) exploration and development of coal, oil and gas, metallic minerals, industrial minerals, and groundwater, 2) environmental applications such as: pollution prevention and site clean-up, 3) hazard prevention and protection in regard to landslides, earthquakes, karst problems, and ground subsidence, 4) engineering of building foundations, roads and highways, railroads, pipelines, utilities, dams, dikes, and locks, 5) city planning in regard to zoning decisions, landscaping, and building codes, 6) regional planning in waste disposal, transportation, and industrial permits, and 7) property valuation in regard to property tax assessment and land acquisition. In short, geologic maps promote sound decision-making in a broad spectrum of activities that are directed towards benefiting man and protecting the environment. The information provided by geologic maps facilitates wise management of the land and its resources.

Geologic maps are normally drawn on topographic base maps that show natural features, cultural features and topographic contours. The scales of topographic base maps and thus the geologic maps drawn on them vary from small-scale to large-scale. Small-scale maps depict large areas in a general manner, whereas large-scale maps depict small areas in much greater detail. Map scales of 1:100,000 or less are generally considered small scales. Map scales larger than 1:100,000 are generally considered large scales. Most modern geologic maps are drawn at large scale on 1:24,000-scale 7.5 minute topographic quadrangle base maps.

Studies show that a 1:24,000-scale geologic map is worth approximately 29 times the cost that one would have to spend gathering the field data and compiling it onto a map.

DGLS has been archiving geologic maps of Missouri for over 100 years. The collection presently contains over 1200 individual geologic maps that cover most parts of the state. These maps were produced by a variety of agencies and individuals, including DGLS, USGS, professors, students, and consultants. Map scales range from small to large. It is worth noting that during the past one dozen years, the geological staff at DGLS has produced 82 detailed 1:24,000-scale geologic maps through the STATEMAP component of the National Cooperative Geologic Mapping Program as administered by the USGS.

Using our Web pages you can locate, view and purchase many of the geologic maps that DGLS maintains in its archival collection located in Rolla, Missouri. They are available by calling the division at 573-368-2125 or by visiting our Publications Desk. To locate our office, view an online map.