GEOLOGICAL APPLICATIONS OF MAPPING SOFTWARE: A CASE STUDY OF STREAM RESPONSE TO TECTONIC UPLIFT OF THE EASTERN FRANCISCAN BELT, NORTHERN CALIFORNIA COAST RANGE

Modern computer technology, including Google Earth and Terrain Navigator Pro, can be utilized as visual and modeling tools for geological research. Image overlays of USGS maps on Google Earth allow three-dimensional visualizations of geologic contacts, faulting and folding, depositional packages, and migrations of stream channels. Terrain Navigator Pro allows topographic profile modeling, slope calculations, and various statistical tools related to horizontal and vertical distances. Mapping software integration allows the user to better determine locations of geological interest, including contacts, slopes, faults, and points of uplift, tilting and other geomorphic expressions. An investigation of California's western Great Valley sequence and Eastern Franciscan Belt of the Coast Range shows stream deflection, migration, and sinuosity responses to tectonics and implies rate of uplift initiated by convergent margin-transform processes (Mesozoic through present). The Eastern Belt currently experiences approximately 5-9 mm of uplift per year and can be considered the structural top of the accretionary wedge comprising the Franciscan Complex. The Great Valley sequence is tilted Mesozoic forearc basin sediments, striking generally N-S to NW-SE, and dipping eastward due to the encroachment of the Coast Range. This contact shows a high rate of slope change due to uplift. Mapping software capabilities are presented using this tectonically active location as a case study. We will present quantitative models of tectonic activity in the Eastern Franciscan Belt to illustrate the utility of the Google Earth and TNPro mapping software. These evolving tools will be of invaluable assistance to geologists in the office and field as visual aids for presentations and interpretation, statistical models and generally assists in investigations before visiting the field. It can assist in quantifying and interpreting results from fieldwork. Additionally, the integration of multiple components can aid in visually grasping multiple spatial events to help constrain, predict, or implicate geologic events.