Stack-unit geologic mapping: color-coded and computer-based methodology

Representing lithostratigraphic successions or stack-unit geologic data on maps is a relatively recent technique in the US for displaying diverse geologic relationships. Complex geologic data can be conveyed on a stack-unit map of color and pattern combinations. This paper describes a computer-based, color-coded methodology for representing geologic data to a depth of 15 meters on a stack-unit map. The constructed map, a stack-unit map of the Paducah 1° × 2° Quadrangle, contains 785 individual polygons that depict 133 different successions of geologic materials to a depth of 15 meters. By using this color and pattern technique, both three-dimensional regional geologic trends and local geologic relationships become easily discernible to the viewer. -Authors