STANDARDIZING AND AUTOMATING DIGITAL GEOLOGIC-GIS MAP SYMBOLIZATION - UPDATED

As of September 2024, the National Park Service’s Geologic Resources Inventory (GRI) program has produced approximately 900 digital geologic-GIS maps. For each of these maps, the depiction or symbolization of geologic features (actual, observed, or measured) has been primarily derived from the features’ source map.

As a result of this approach, the symbolization of geologic features is not fully standardized, and thus the symbolization of a specific geologic feature on one map may differ from the symbolization of that same feature on another map. In addition, the process of assigning map symbols to geologic features has utilized non-standard and often incomplete ESRI symbology stylesheets (e.g., Geology 24K or Mining), and is often time consuming and inefficient.

In an effort to standardize how geologic map features are symbolized on digital geologic-GIS maps, the GRI has recently developed a geologic map symbolization standard that is based on the Federal Geographic Data Committee (FGDC) Digital Cartographic Standard for Geologic Map Symbolization. The process for producing geologic map symbolization has also been automated through GRI-developed custom tools that efficiently and accurately produce geologic feature symbolization.