Spatial Signatures of Mapping Expertise Among Field Geologists

Abstract

Geologists consider field mapping skills necessary for the development of expertise in geology. We discuss the results of a day-long geology mapping exercise in the Tobacco Root Mountains, Montana, USA. Sixty-seven volunteer geologists, chosen specifically to represent a continuum from novice to expert, were asked to create a map of bedrock geology for approximately 70 square hectares. In order to identify and assess field mapping strategies, GPS tracks of each participant's field activities were analyzed using GIS and sequence alignment techniques. Results indicate differences in routes used during the field task by participants with varying levels of mapping expertise. To investigate this result, the field area was divided into thirty-three sub-regions based on topography, vegetation, rock outcrops, and participant traffic. Using these sub-regions, multiple variables such as amount of time spent in each sub-region and the order in which these sub-regions were visited were determined for each participant. Geologic mapping experts and others who are able to produce highly accurate maps recorded similar spatio-temporal sequences during the task, likely related to development of a reasonable structural hypothesis early in the task. These results have implications for field education and emphasize the role of working hypotheses in informing the movement of experts in the field.