Iowa Bedrock Geology 1:500,000-scale

The bedrock geologic map portrays the current interpretation of the distribution of various bedrock stratigraphic units present at the bedrock surface. The bedrock surface is buried by unconsolidated surficial sediments (mostly Quaternary) over most of its extent, but this surface coincides with the modern land surface in areas of bedrock exposure. The map is consistent with all available data including drill records and well samples, as well as surface bedrock exposures (both natural and man-made) and shallow-to-bedrock soils units (NRCS county soils maps). Mapped stratigraphic intervals are portrayed primarily at the group level (i.e., a grouping of bedrock formations), each characterized by distinctive lithologies (rock types) summarized in the map key and associated metadata. The distribution of bedrock units was mapped to conform to the current map of bedrock topography (elevation of the bedrock surface). The structural configurations of relevant stratigraphic datums were intercepted with the bedrock topographic surface to produce the map contacts. The line style shown on the bedrock geologic map qualitatively reflects both data density and degree of certainty of individual stratigraphic contacts. Downloadable

Data and Resources

Metadata Source

Additional Info

Field Value
Citation Date 2010-01-01T12:00:00

Harvest Information

Original ID 66bb6bbde013946035700d274f112205
Index Date 2014-09-25T19:54:38Z
Original Format ISO-USGIN
Original Version 1.2


Name Brian J. Witzke, Raymond R. Anderson and John P. Pope
Position missing
Organization Iowa Geological and Water Survey, Department of Natural Resources

Geographic Extent

North Bound 43.576659396952
South Bound 40.509883081148
East Bound -90.11303214713
West Bound -96.836664959636