Data Summary

Glacial Deposits of Northwestern Pennsylvania

2018 - Allegheny College




Digitized regional surficial geology map for northwestern Pennsylvania. The complete citation for the paper map is: Map of the Glacial Deposits of Northwestern Pennsylvania by V.C. Shepps, J.B. Droste, and R.F. Sitler under the supervision of G.W.White, 1959, Bulletin G-32, Pennsylvania Geologic Survey. The original map was published at a scale of 1:125,000. Three counties are fully covered by these deposits and mapped (Crawford, Erie, and Mercer); five more are partially covered and mapped (Beaver, Butler, Lawrence, Warren, and Venango). This GIS dataset shows the areal distribution of 14 distinct glacial deposits from the Pleistocene Epoch and Recent stream alluvium and/or bedrock exposures. All mapping activity and lithologic interpretations were made by the original authors of the map (Shepps et al., 1959); the authors of this electronic geospatial resource (Shaffer et al., 2005) have only provided digital transfer of the map features and attributes and documentation of the process. Purpose: This dataset identifies the distribution of surficial unconsolidated sediments (glacial deposits and stream alluvium) in northwestern PA. This map is the only published comprehensive regional surficial geologic map available for the region. The original map was digitized to provide an electronic version for GIS work. Potential users should read the Supplemental Information Section (below) to determine the appropriate scale for using these data. More detailed surficial geologic maps may exist within the mapped area in either paper or electronic format. Researchers are encouraged to check with the U.S. Geological Survey, Pennsylvania Geologic Survey, PASDA, and/or Geology Departments at local universities and colleges for other maps.