SURFICIAL GEOLOGY OF JACKSON COUNTY, OH, USA

The Ohio Geological Survey’s long term-plan of three-dimensional mapping the state is important for derivative applications relating to groundwater and subsurface modeling, material resource management, geologic hazard analysis and mitigation, glacial research, and many other fields. Since the late 1990s, surficial geology “stack” maps of parts of Ohio have been created to illustrate the material types and thicknesses of the unconsolidated surficial units to the bedrock surface. These products are mapped at a scale of 1:10,000 and, although they function as a digital dataset to be used in a GIS environment, are typically published at either 1:24,000 (7.5-minute quadrangles) or 1:62,500 (county-wide scale). Jackson County was one of the last unmapped areas needed to complete the first seamless, gapless statewide surficial geology mapping dataset for the state. This surficial stack map was produced by combining interpretations from field observations, literature review, subsurface logs (e.g., reviewed water wells and geotechnical borings), soil surveys, 2.5 ft x 2.5 ft resolution LiDAR digital elevation models, and collected passive seismic data.

Jackson County is an area dominated by consolidated Paleozoic bedrock from the Appalachian Plateau and various unconsolidated Quaternary-aged deposits. Although this region lies beyond the maximum extent of ice from past glaciations, influence of the ice age is indicated by the presence of numerous slackwater valley fill terraces. Many of these lacustrine deposits are a result of pre-Illinoian drainage modifications caused by ice-damming of the preglacial Teays River Valley and its tributaries. Dammed valleys led to the development of a large proglacial lake (Lake Tight), the eventual incision of drainage divides where rising lake water levels spilled over cols, and the subsequent drainage reversals of streams into underfit valleys. This mapping project refined the extent of these depositional and erosional features and others, which aided in the reconstruction of pre-Quaternary drainage for the county. These surficial datasets support regional projects for county planners and researchers.