Recovering Legacy Geological Data into a Geospatial Database Product: An Example from Baja California Norte, México

Alexander Audet, University of Maine


This project develops a workflow for the extraction of legacy geological map data using a case study in the Baja California Norte, México by four workers over forty years. This project is unique from other digitization efforts worldwide because the data were already in an unregistered vector format, instead of a raster format. Thus, the methodology used in this project took advantage of this digital format by writing arcpy scripts for use inside of ArcMap, and using database feature manipulation software, in order to streamline the data extraction process, with the goal being to develop methods for dealing with other similar legacy geological datasets. The project was conditionally successful, with the developed arcpy script extracting strike and dip direction information from the structural geological data, with only minimal manual review required. Additionally, implementation of the FME Workbench software allowed text information describing Dip and Plunge to be extracted and combined with its companion direction and position data; however, project limitations only allowed for a method that required extensive manual review after the automated process. Transferability of the developed workflow is limited by requiring access to FME workbench software in addition to ArcGIS, but as that part of the workflow requires substantial manual work, it could perhaps be replaced by completely manual methods. Additionally, the arcpy scripts might not work properly if used on tightly clustered data, or data constructed differently than the Baja California data. Copies of the arcpy script, FME workflows, and maps can be found on