| Reference | {Deposit:: SCHWARTZ, G. ET AL, 1959, INVESTIGATION OF THE COMMERCIAL POSSIBILITIES OF MARL IN MINNESOTA, OFFICE OF IRON RANGE RESOURCES AND REHABILITATION}{Deposit:: ROEPKE, HARLAN, 1958, THE NISSWA LAKE MARL DEPOSIT, CROW WING CO., MN, UNIV. OF MINNESOTA, M.S. THESIS.}{Deposit:: STAUFFER, C.R., AND G.A. THIEL, 1933, THE LIMESTONES AND MARLS OF MINNESOTA, MINNESOTA GEOLOGICAL SURVEY BULL. 23.}{Production:: SCHWARTZ, 1959, INVEST. OF POSSIBILITIES OF MARL IN MN} |