GEOLOGIC MAP OF THE RUSSELLVILLE 100K SHEET

The USGS is combining existing and new geologic maps to expand coverage across the nation, helping to identify diverse resources and geologic hazards, while also benefiting infrastructure planning. Current mapping in Arkansas covers a series of 100k sheets in a transect that includes the Ozark Dome, the Arkoma Basin, and Ouachita Mountains. The Russellville 100k sheet is the first map nearing completion and it integrates existing geological mapping, new LiDAR data, new geophysical surveys, and field observations into a digital format. The Russellville sheet contains a sequence of Middle Pennsylvanian strata deformed by flexural normal faults and overprinting thrust faults that collectively formed the Arkoma foreland basin during the late Paleozoic Ouachita orogeny. The database behind the GIS-based mapping uses the Seamless Integrated Geologic Mapping extension to the Geologic Map Schema (SIGMa – GeMS), which has the capacity to tie together stratigraphic, spatial, and temporal information at regional and national scales. This product also added a 3-class fault hierarchy based on amount of offset for each fault to improve map readability in structurally complex areas. The mapping uses a relatively new province structure that combines map units based on their genetic origins. This province structure is flexible and easily expanded as new data become available.