2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 38-27
Presentation Time: 9:00 AM-5:30 PM


SHAFFER, Christopher, GIS Manager, Allegheny College, 520 N Main St, Meadville, PA 16335 and O'BRIEN, Rachel, Department of Geology, Allegheny College, Meadville, PA 16335, cshaffer@allegheny.edu

Over the course of ten years, regional geoscience mapping in northwestern Pennsylvania has provided more than 40 Allegheny College students with a diverse range of opportunities to learn how to use geographic information systems (GIS) to capture, manage, analyze, and present geospatial data and information. Maps contained within published reports by the Pennsylvania Geological Survey (PAGS) that only exist in hardcopy format have been converted to digital files for use within a GIS. Through this process, students have gained experience using ArcGIS Desktop software to scan and georeference maps, design geodatabase schemas, perform on-screen digitizing, implement tests for assessing quality, and write metadata. Currently, three published maps are available for download by GIS users on the Pennsylvania Spatial Data Access (PASDA) on-line data repository. The largest of these is a surficial glacial geology map that covers 11,370 km2, includes 1595 polygons attributed with six distinct lithologic and stratigraphic descriptors. Another ten maps depicting bedrock geology, fracture traces, and sediment thickness contours are currently in various stages of development. Once complete, these digital map layers will be available to support countless types of spatial analysis in geologic applications. A second project centered on bedrock elevation mapping has also provided students with opportunities to broaden their knowledge and skillsets. Through the process of cross-referencing historic groundwater and oil and gas well records, tax parcel boundaries, emergency address points, roadways, and aerial photos, students have plotted the locations of over 11,500 wells and assigned location accuracy codes for those wells in Crawford, Erie, and Mercer counties, PA. These points, coded with depth to bedrock, lithologic quality codes, and other pertinent characteristics, allowed for the hand-contouring of bedrock elevation and the eventual digitizing of such information. ArcSDE (spatial database engine) was leveraged to facilitate central data management, workflow streamlining, multiuser editing, editor tracking, data backup and recovery. These experiences have allowed students to integrate GIS into their senior thesis projects and build skill sets that are valued by prospective employers.