1. Geology of the metamorphosed Biwabik iron-formation, Eastern Mesabi district, Minnesota, Bulletin 43, Plate 1 Maps University Of Minnesota Public content 1962. Gundersen, J.N. and Schwartz, George M. (George Melvin), 1892-1980. Generalized geologic map and longitudinal diagram of the Eastern Mesabi District, Minnesota, scale 1 inch = about 1 1/4 mile. Minnesota Geological Survey.