FOCUS AND PERSPECTIVE IN THE BONNEVILLE LAKE BASIN, UTAH: SOLVING SCIENTIFIC PROBLEMS WITH QUADRANGLE-BASED QUATERNARY GEOLOGIC MAPPING

Quadrangle-based Quaternary geologic mapping is a highly sophisticated, intellectually demanding, scientific process which results in a map that represents the proposed solution to one or more geologic problems. Quaternary geologic mapping is not a simple cataloging of sediment types, but rather a highly complex intellectual activity that requires the mapper to conduct intensive spatial analysis and to devise and test numerous sets of multiple working hypotheses. Mapping in a new area is not repeating what was accomplished on a previous map. Each quadrangle contains a unique assemblage of landforms, earth materials, and structural elements and each map concerns a different and unique set of geologic problems. Mappers, therefore, need solid research skills and extensive knowledge of geomorphology, sedimentology, stratigraphy, air photo interpretation, photogrammetry, cartography, and GIS to address the multitude of varied Quaternary geologic problems that exist within a quadrangle area. Successful Quaternary mappers must be familiar with a great variety of geologic processes as well as with the dominant regional problems and the regional geologic history. Having perspective on important thematic and regional questions helps the researcher recognize relevant data during the focused study of the quadrangle area and to apply those data to answering the broader questions. A completed geologic map is a visual representation of spatially portrayable results of the intensive research conducted during the mapping process. As in other types of publications, the research results portrayed on a geologic map contain elements of generalization and interpretation in addition to description. Thus, despite the impression of certainty that geologic maps leave on many readers, like other research products, they are subject to reanalysis and revision over time. Scientific benefits derived from integrating the focused study through mapping of a 1:24,000 scale quadrangle with regional and thematic perspectives are illustrated with examples from the Bonneville lake basin of northwestern Utah. The examples illustrate how quadrangle mapping in the Bonneville basin has contributed to understanding climate change and resource exploration science.