[Society of Exploration Geophysicists and Environment and Engineering Geophysical Society Symposium on the Application of Geophysics to Engineering and Environmental Problems 2014 - Boston, Massachusetts (16 March to 20 March)] Symposium on the Application of Geophysics to Engineering and Environmental Problems 2014 - RESULTS FROM AN AIRBORNE MAGNETIC STUDY FOR LOCATING LEGACY WELLS IN DEVELOPING SHALE GAS REGIONS OF SOUTHWESTERN PENNSYLVANIA