IRON ORE RECOVERY POTENTIAL FROM BENSON MINE TAILINGS: USING COMMUNITY PROBLEMS TO SERVE AS A TEACHING METHOD

In 1950, Benson Mines at Star Lake, New York was the largest open pit magnetite iron ore mine in the world. In 1978, when Benson Mines closed, 470 people lost their jobs. During the operation of the mine large amounts of tailings were dumped in the area surrounding the mine. Renewed interest in mining the tailings for the magnetite and martite they contain led to the present investigation. This mining, geologic and economic problem, was used to provide a meaningful educational experience for students in applied geophysics. Students were exposed to a real world practical problem requiring the selection of geophysical methods, planning of the field work, conducting field surveys and analysis and interpretation of the data.

The students decided on three geophysical methods to conduct the survey. Seismic refraction and electrical resistivity methods were used to determine thickness of the tailings. The resistivity and magnetic methods were used to detect anomalies that may be due to magnetite concentrations in the tailings. Magnetic, gradiometer and electrical resistivity maps were constructed to determine if magnetite was present in certain areas and to estimate its depth.

This hands-on approach in which students work on a real problem serving the community proved to be an effective method of teaching geophysics. The method requires the students to do science by collecting appropriate data and to analyze and interpret the data. For each phase of the investigation students developed field skills as well as observation and reasoning skills necessary for the problem solving.