OHIO SURFICIAL GEOLOGY: 3D VISUALIZATIONS FROM 2D MAPS

Since 1997, the Ohio Department of Natural Resources, Division of Geological Survey has conducted reconnaissance-style, two-dimensional (2D) mapping with attributes representing the thickness of glacial deposits in the third dimension (3D). Early efforts focused on mapping densely populated urban corridors of the state to provide value-added products or derivative maps. Referred to as “stack maps,” the maps feature a network of polygons individually labeled to identify the “stack” and relative thickness of materials, such as glacial till, sand and gravel, and fine-grained lacustrine deposits, found in each polygon. A multitude of layer files are used to create the stack maps, including bedrock geology, glacial geology, drift thickness, digital elevation models, soils, historic maps, and high-resolution LiDAR imagery. These layers overlay detailed base maps supplemented by detailed point data available from digitized ground-water well logs, oil-and-gas well logs, measured sections, electronic wire logs, Ohio Department of Transportation engineering bore-hole logs, and geotechnical logs. Currently, 72 percent of the state is mapped using these techniques.

For 2013–2014, the western half of the Hillsboro 30 X 60-minute quadrangle was mapped. In this project, 2D polygons from the map area were used to create a 3D representation of the extents and thicknesses of lithologic units bounded by the lower bedrock topography and the upper digital elevation model. The 2D polygon attributes from the stack map were used to construct the vertical components (or stacks) filling the 3D environment in ESRI ArcScene. The resulting 3D conceptual models advance understanding of the extents and distribution of geologic materials in the shallow subsurface while also enhancing mineral resource assessment, improving recognition of geologic hazard potential, and aiding ground-water resource management.