DEVELOPING A 3D GEOFRAMEWORK MODEL FOR KY USING BEST AVAILABLE DATA AND PRACTICES

The Kentucky Geological Survey continues its efforts to develop 3D data elements from the best available 2D resources while documenting best practices for these processes and for the dissemination of available products to researchers and stakeholders. Digitized structure contours, geologic map units, and Digital Elevation Models were utilized within ArcGIS Pro to construct 3D surfaces for shale units in central and eastern Kentucky as well as the Jackson Purchase, with interpolative iterations being performed until each 3D object best represented current geologic understanding. Automated 3D surface interpolation using Jupyter Notebooks in ArcGIS Pro can be an efficient and effective method for creating 3D multipatch objects which closely represent geologic features that are otherwise difficult to visualize. For shales, 3D geologic units were produced for the Cumberland Fm, the Kope/Clays Ferry Fm, the Osgood Fm, the Crab Orchard Fm, the Borden Fm, and Pennsylvanian coal-baring marine shales. Regionally, the interpolated 3D shale units reflect the expected Cincinnati Arch structure when vertically exaggerated and will be useful in future landslide modeling and analysis. An in-depth inventory of data for surface interpolation in the Jackson Purchase was also conducted and datasets containing relevant structure contours were geo-referenced and digitized before being converted to 3D surfaces. Tops in the Jackson Purchase were modeled for the New Albany Shale, Paleozoic-Era bedrock, the McNairy Fm, the Porters Creek Clay, and the Wilcox Fm. These Jackson Purchase units represent some of the only remaining post-Paleozoic-Era strata in Kentucky and will be useful for studying erosional processes and seismic activity within continental deposits. In addition to stratigraphic horizons, a predictive 3D depth to bedrock model for the Ohio River Valley in Kentucky was interpolated using predictive models by Shangguan, et al. (2016) and USACE Hydrographic Surveys, showing river alluvium and bathymetric information, with geographic context. An elevation profile of the modeled Ohio River Valley’s 3D bedrock surface closely aligned with the 1957 USGS Water Supply Paper #1411’s Plate 3 deep channel bedrock profile, demonstrating the accuracy these methods can lend for modeling geologic surfaces in 3D.