3 Advances in Geologic Mapping, Databases, and Dissemination: Establishing fundamental resources for the earth science community
This session will highlight new geologic maps, innovations in mapping techniques, and related advances in data management, web accessibility, and applications. We welcome submissions with relevance to hazard assessments, natural resource evaluations, and water-land management.
Monday, 9 March 2026
9:00 AM - 12:00 PM
RCC, 105
Unlocking the Potential of Historical Geologic Maps: Designing a Simple Open-Source Georeferencing Application
Paper number: 3-7
Program: Technical Sessions
Time: 11:00 AM – 11:30 AM
Authors
Abstract
The Tennessee Geological Survey (TGS) curates extensive historical geologic and mineral-resource collections, including thousands of scanned maps documenting primary geologic field observations, drillhole locations, mining history, and geochemical and mineralization data—resources of renewed interest amid efforts to expand domestic sourcing of critical minerals. Over the past 15 years, TGS and the U.S. Geological Survey have invested in long-term preservation, resulting in more than 15,000 documents being scanned, metadata created, and stored in a digital repository. However, most map-based records remain difficult to discover and use because they lack geospatial indexing; users must rely on basic keyword metadata (e.g., quadrangle and county names) rather than a true spatial search.
This presentation introduces a lightweight, open-source georeferencing application designed to accelerate the creation and editing of spatial footprints for scanned historical maps. Developed in Python using open-source libraries, the tool opens common raster formats as well as PDFs and supports both traditional affine georeferencing and a “synthetic affine” approach that enables rapid, guided placement when control information is limited. Users can digitize custom areas of interest and export polygon features to common open geospatial formats as well as Esri-compatible GIS datasets, including direct creation and editing within ArcGIS Online feature layers. The application can also generate world files and export images for viewing in situ within standard GIS software. By streamlining footprint production and georeferencing workflows, this tool supports improved spatial discovery and broader reuse of legacy geologic map information.
Geological Society of America Abstracts with Programs. Vol. 58, No. 1
doi: 10.1130/abs/2026SE-411906
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