REVISITING NEARBY OUTCROPS TO BUILD DEPTH IN UNDERSTANDING: A TECHNIQUE FOR BUILDING TRANSFERABLE FIELD OBSERVATION AND INTERPRETATION SKILLS

In many introductory and advanced-level college courses first-hand field experiences are typically short-lived (two hour or one day), single events. Students rarely get the opportunity to revisit the outcrop or locality after they have completed a report. Student field experiences that focus on repeat visits to a nearby locality are an excellent means of building depth of student understanding and learning for the following reasons: 1. Students are able to ‘see’ errors or omissions in their first set of field notes. 2. Students get feedback on their work, and master the first step before progressing to work that requires slightly higher-order thinking skills. 3. Students also gain an appreciation for full and accurate field observations and notes. 4. The practical problems of limited transport, funds, travel time, and outcrop availability are reduced.

Two examples of areas used for this approach are: 1) The Ordovician sedimentary sequence exposed in the bluffs of the Mississippi River in the Minneapolis-St. Paul area. First, students learn about geomorphology, topographic maps, and the drawing of simple topographic profiles. Second, they learn about the sedimentary rocks that the gorge is carved in, as they measure a stratigraphic section. Third, they learn about the regional context. Fourth, they learn about the possible depositional settings. Finally, they learn about the paleontological record preserved in the rocks, and its use and application. 2) Glacially polished bedrock surfaces of Central Minnesota, in which granite and associated intrusive rocks are cut by basalts. First, igneous processes and rock types are introduced. Second, the intrusive relations can be evaluated. Third, the role of fractures can be assessed. Finally the techniques of field mapping can be introduced, and aspects of igneous petrogenesis can be discussed.

This approach of revisiting outcrops forces students to appreciate and gain skills that are used: 1. When a geologist makes a single visit to a remote field locality, and 2. When a geologist makes multiple visits to a field locality. This approach also promotes student appreciation for the depth and breadth of knowledge and understanding required to make complete observations and interpretations. These skills are eminently useful and transferable to other disciplines.