2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 33
Presentation Time: 6:00 PM-8:00 PM

GEOLOGIC AND MINERAL LOCALITIES MAP DATABASE OF LIBERIA


WAHL, Ronald R., U.S. Geological Survey, P.O. Box 25046 Mail Stop 980, Denver, CO 80225, rwahl@usgs.gov

Ten 1:250,000-scale U.S. Geological Survey geological maps and ten corresponding mineral localities maps of Liberia were digitized and attributed using ArcGIS from ESRI. Map topology was built and maintained in an ArcGIS geodatabase. A data dictionary was used to build the ArcGIS geodatabase and then lookup tables for each feature class within the geology and mineral localities feature data sets. These lookup tables were then linked to the appropriate feature class attribute table with relationship classes. Map units of point, line and area geometries, faults and contacts were assigned graphic styles separately in ArcMAP. Four digital publication-quality maps using the ArcMAP module of ArcGIS were made showing the geologic data with images showing the planimetric data, shaded topographic relief using Shuttle Radar Topographic Mission 90-meter digital elevation data, and two country-wide geophysical data sets: processed aeromagnetic and aeroradiometric images. The mineral data on this map were divided into five categories based on economic value: non-metallic, metallic, precious metals, energy, and gemstones. The final geodatabase will be useful in making mineral assessments, as well as many civil projects.