First published in 1937 and last revised in 1991, the state geologic map is updated periodically to incorporate new geologic information and up-to-date rock classifications. This new 2008 data revision includes a shift in the boundary between the Pennsylvanian and Permian bedrock, which was recently redefined by the geologic community. The data for the 1991 map was digitized from an original paper copy publication of Map M-1, "Geologic Map of Kansas," (1964), which incorporated a 1:500,000-scale USGS base map. The goal of that project was to capture, in GIS format, the spatial and attribute information portrayed on the 1964 map. This data is from the Kansas Geological Survey - Cartographic Services and its predecessors.

First published in 1937 and last revised in 1991, the state geologic map is updated periodically to incorporate new geologic information and up-to-date rock classifications. This new 2008 data revision includes a shift in the boundary between the Pennsylvanian and Permian bedrock, which was recently redefined by the geologic community. The data for the 1991 map was digitized from an original paper copy publication of Map M-1, "Geologic Map of Kansas," (1964), which incorporated a 1:500,000-scale USGS base map. The goal of that project was to capture, in GIS format, the spatial and attribute information portrayed on the 1964 map. This data is from the Kansas Geological Survey - Cartographic Services and its predecessors.