The Heavy, Non-Magnetic Residuals of Certain Samples Collected by the Wisconsin Geological Survey Open-file report; contains unpublished data that has not yet been peer-reviewed. Metallic Minerals Rocks and Minerals Data and Resources WOFR1916-01 The Heavy, Non-Magnetic Residuals of Certain Samples Collected by the Wisconsin Geological Survey Steidtmann, E.; 1916 Report: 6 p. Download Related Collections Open-File Report View Open-File Report