AGGREGATE RESOURCE MAPS DERIVED FROM OHIO'S STATEWIDE SURFICIAL GEOLOGY DATASET

Compilation of surficial geology mapping in Ohio was completed in 2022 and established the consistent geologic framework needed for resource derivative mapping. Prominent natural resources in Ohio include sand-and-gravel (SG) and carbonate bedrock. These aggregate resources combined were valued at over $1 billion in 2021, which represented about 78% of the annual value for all nonfuel mineral production. This statewide derivative mapping project identified potential new sources of aggregate based upon lithology, thickness, and extent of unconsolidated surficial sediments. Any surficial geology areas containing sand or gravel were evaluated as potential resources. These resources are considered potentially mineable if they are more than 6 m (20 ft) thick and buried by less than 3 m (10 ft) of fine-grained material. Carbonate bedrock resources in the western and central portions of the state were also evaluated and only areas with less than 12 m (40 ft) of overlying sediments were considered potentially viable resources.

Extensive data review validated areas identified by these resource criteria. Thousands of water well logs were examined and adjusted, providing data that were unavailable during earlier mapping. Aggregate mines opening or expanding prompted the review and remapping of their boundaries during this derivative mapping process. A visual inspection of active and historic aggregate mine operations was used to verify the efficacy of the derivative mapping methodology and definitions of potential resources. Statewide, 13,388 (34%) of the 39,422 GIS polygons in the dataset were reviewed, including all potential SG and carbonate resources, and all pits and quarries. In total, the available SG resources cover an area of 9,197 km² (3,551 mi²) with an average thickness of 22 m (73 ft), resulting in a total volume that would approximately fill half of Lake Erie. These map layers are available for viewing and download on the Ohio Geology Interactive Map.

The delineation of these potential resources can be used to support the sustainable development of these natural resources as demand for aggregate materials continues to increase. In the future, work could be done to determine the true suitability of these resources for development, including economic, geotechnical, and geochemical analysis.