DETAILED, THREE-DIMENSIONAL, SURFICIAL-GEOLOGY MAPPING OF THE MILAN, OHIO 1:24,000 QUADRANGLE

The Central Great Lakes Geologic Mapping Coalition (CGLGMC) is a partnership among the state geological surveys of Ohio, Indiana, Illinois, and Michigan, and the U.S. Geological Survey. The mission of the CGLGMC is to produce detailed, three-dimensional geologic maps and information, along with related digital databases, that are required to support informed decision-making involving ground water, mineral-resource availability and distribution, geological hazards, and environmental management. With rather moderate startup funding, pilot-mapping projects were undertaken in each of the four states. A primary objective of the Ohio pilot project (the Milan quadrangle) was to acquire the technology and knowledge to develop efficient methodologies for production of three-dimensional geologic frameworks. For this work, various tools within ArcGIS were used to construct the bounding surfaces of each geologic unit and to produce grids that allowed depiction of the three-dimensional framework of surficial and bedrock geologic units. Data sources used for this effort included archival field sections and other legacy data, NRCS soils maps, new seismic-refraction surveys, and boring logs from ODOT, OEPA, BUSTR, Division of Water, and engineering firms. All data were prepared for three-dimensional analysis. The resultant three-dimensional model can be manipulated to produce a range of derivative products to address the wide variety of water-management, land-use, environmental, and resource issues that are crucial to local, state, and federal agencies, private industry, and the general public.