GEOLOGIC MAPPING STRATEGIES OF NOVICES AND EXPERTS AS EVIDENCED THROUGH GPS TRACK AND MAP ANALYSIS

Strategies of experts and novices during mapping of two field localities were examined to better understand the nature of expert cognition in the geological sciences. Two day-long (4-8 hour) mapping projects took place at field locations near Marquette, Michigan. Each field site required a different mapping approach; at one site, participants mapped cross-cutting relationships between rock units exposed in intermittent outcrops in a ~100 meter by 300 meter area, whereas at the second site, participants mapped rock units that form a structurally complex syncline exposed in vertical cliffs of a quarry and road cut over a horizontal distance of 1.5 km. Seven participants representing a continuum of prior geologic study and field mapping experience, ranging from none to 10+ years, took part in the study. Three undergraduates and a master's student mapped sites during normal activities in a required field methods course, and the remaining participants (a PhD student, professional geologist, and college professor) mapped the following day.

We recorded complete GPS tracks of participant movement during the mapping activities, and collected both paper maps and field notes produced by participants during the exercises. Participant maps were converted to digital format and matching polygons or polygon groups between maps were paired for analysis. We also compared participant maps to a USGS bedrock map though the analysis of polygon shape and centroid distance metrics. GPS tracks collected during mapping activities were analyzed for specific hot spots of participant activity, as well as general trends in spatial pattern. Finally, participant activity as evidenced in the GPS tracks was associated with specific mapped features. Comparison of tracks from novices and experts showed marked differences in track simplicity, hot spot location, and general trends, suggesting preconceived strategies. A wide range of map features, mapping accuracy, and mapping strategies were apparent among both novice and expert geoscientists.